Title: A K19E missense mutation in the plasminogen gene is a common cause of familial hypoplasminogenaemia.
Date: - (dd/mm/yy) - 06/01/06
Authors: Tefs K, Tait CR, Walker ID, Pietzsch N, Ziegler M, Schuster V.
Abstract: 1: Blood Coagul Fibrinolysis. 2003 Jun;14(4):411-6.
A K19E missense mutation in the plasminogen gene is a common cause of familial hypoplasminogenaemia.
Tefs K , Tait CR , Walker ID , Pietzsch N , Ziegler M , Schuster V .
Children's Hospital, University of Leipzig, Germany.
The prevalence of familial plasminogen deficiency in Scotland has recently been calculated at 2.9/1000. However, little is known of the molecular genetic background and the frequency of plasminogen gene mutations in most cases of inherited plasminogen deficiency. Having previously identified 28 unrelated subjects with familial plasminogen deficiency from a cohort of 9611 blood donors, we have now reviewed 19 of these 28 subjects and screened the plasminogen gene in 15 subjects with hypoplasminogenaemia (plus five relatives) and four subjects with dysplasminogenaemia for mutations and polymorphisms. A missense mutation K19E in the plasminogen gene was found in 13 of the 15 propositi with hypoplasminogenaemia, in one of these in a homozygous manner. In two subjects with hypoplasminogenaemia, two new mutations (P353A and R471X) were identified. These three different mutations, if inherited in a homozygous or compound-heterozygous manner, may be associated with the development of ligneous conjunctivitis. In four subjects with dysplasminogenaemia, three heterozygous mutations (C548G, n = 1; A601T, n = 1; G693R, n = 2) were found. None of the propositi with plasminogen deficiency developed venous thrombosis at any time. In conclusion, the K19E mutation in the plasminogen gene is a common cause of hypoplasminogenaemia in Scotland, with an estimated prevalence of around 0.14%.
PMID: 12945885 [PubMed - indexed for MEDLINE]
NCBI | NLM | NIH
Department of Health & Human Services
( read full article )
Sources on the web: - NCBI - PubMed
Related publications: 1: Blood Coagul Fibrinolysis. 2003 Jun;14(4):411-6.
Related documents to download: -
Notes: -
Year: 2003
Title: Ligneous conjunctivitis in a patient with plasminogen type I deficiency: case report
Date: - (dd/mm/yy) - 02/01/06
Authors: P. Meyer - Universitäts-Augenklinik Basel, Basel/CH
S. Turtschi - Universitäts-Augenklinik Basel, Basel/CH
J. Messerli - Universitäts-Augenklinik Basel, Basel/CH
Abstract: Meeting Abstract
Publisched 22-09-2004
by GMS
Evidenzbasierte Medizin - Anspruch und Wirklichkeit. 102. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft. Berlin, 23.-26.09.2004. Düsseldorf, Köln: German Medical Science; 2004. Doc 04dogDO.13.02
Ligneous conjunctivitis in a patient with plasminogen type I deficiency: case report
Text
Objective
Ligneous conjunctivitis is a rare, chronic, recurrent pseudomembranous conjunctivitis forming nodular masses on the palpebral conjunctiva.
Methods
Case report with clinical and histopathological diagnostic findings.
Results
A 31-year-old woman patient developed a therapy resistant, chronic conjunctivitis after intraocular surgery (secondary implantation of a posterior chamber lens). Large papillae with whitish deposits on the superior tarsal region were found. The tarsus was deformed by scaring lesions. Because of congenital cataract with secondary glaucoma, the patient was repeatedly operated on both eye. In November 2003, a surgical excision of the papillomatous deposits was performed with parallel cryotherapy of the tarsus. On histology, both granulation tissue with accompanying inflammatory infiltrate and necrotic areas and clotted fibrin deposits were found. The analysis of clotting parameter revealed a plasminogen deficiency of 17% compared to normal values. The conjunctivitis could be positively influenced by an after-treatment with a therapeutic contact lens and hyaluronic acid.
Conclusions
In chronic, therapy-resistant conjunctivitis with whitish, pseudomembranous, fibrin-rich deposits, especially after surgery, an early biopsy of the conjunctiva with histological examination is necessary. In suspect of conjunctivitis lignosa, the diagnosis can be confirmed by detection of a plasminogen type I deficiency.
© 2004 Meyer et al; licensee . This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.
gms german medical science | The Portal of the Association of the Scientific Medical Societies in Germany | AWMF DIMDI ZB MED
(read full article)
Sources on the web: - the article's original URL.
- GMS
Related publications: 102. Jahrestagung der DOG Deutsche Ophthalmologische Gesellschaft e.V. 23. bis 26.09.2004, Berlin
Related documents to download: -
Notes:
Year: 2004
Title: Ligneous Conjunctivitis news
by:CANCER-HELP.ORG
Date: - (dd/mm/yy) - 01/01/06
Authors: CANCER-HELP.ORG
Abstract:
Web Resources for Ligneous Conjunctivitis --> BATEMAN (1986) - LIGNEOUS CONJUNCTIVITIS
Features Listed For BATEMAN (1986) - LIGNEOUS CONJUNCTIVITIS. McKusick: 217090.
Ligneous conjunctivitis: a local manifestation of a systemic ...
Ligneous conjunctivitis: a local manifestation of a systemic disorder?
Ligneous conjunctivitis.
Click here to read Ligneous conjunctivitis. ... Actually, systemic plasminogen deficiency
5 lock
Topic :- Ligneous Conjunctivitis Message :- My 3 year old daughter has been diagnosed
Conjunctivitis Ligneous,Ligneous Conjunctivitis
Conjunctivitis Ligneous,Ligneous Conjunctivitis,Conjunctivitis Ligneous,Ligneous
Conjunctivitis, Ligneous
Ligneous Conjunctivitis is a rare disorder that is characterized by recurrent lesions
Ingenta: Article Summary -- Otolaryngological manifestations of ...
Otolaryngological manifestations of ligneous conjunctivitis International Journal
Ingenta: article summary -- Ear involvement in ligneous ...
Ear involvement in ligneous conjunctivitis: a rarity or an under-diagnosed condition?
#217090 CONJUNCTIVITIS, LIGNEOUS
Ligneous conjunctivitis is a rare pediatric disorder characterized by chronic tearing
TYPE I PLASMINOGEN DEFICIENCY AND LIGNEOUS CONJUNCTIVITIS
TYPE I PLASMINOGEN DEFICIENCY AND LIGNEOUS CONJUNCTIVITIS. JP McCluskie,
Ligneous cervicitis - BJOG: An Internal Journal of Obs Gyn, Vol ...
In one case, ligneous conjunctivitis was induced by antifibrinolytic treatment
Ligneous cervicitis - BJOG: An Internal Journal of Obs Gyn, Vol ...
Ligneous conjunctivitis and the cervix. Br J Obstet Gynaecol 2003;110: 1032-1033. ... Ligneous
BJO -- KLEBE et al. 83 (7): 878
Immunohistological findings in a patient with unusual late onset manifestation
Membranous, Pseudomembranous and Ligneous Conjunctivitis
File Format: PDF/Adobe Acrobat
Karger Publishers
1st quarter 04. Cicatrising Conjunctivitis De Cock R: Membranous,
Conjunctivitis, Ligneous
Ligneous Conjunctivitis is a rare disorder that is characterized by
Conjunctivitis, Ligneous
Ligneous Conjunctivitis is a rare disorder that is characterized by recurrent lesions
Bacterial Conjunctivitis -- eCureMe.com
Industrial pollutants; Smoke; Facial creams; Ultraviolet light; Sarcoidosis;
Viral Conjunctivitis -- eCureMe.com
Industrial pollutants; Smoke; Facial creams; Ultraviolet light. Sarcoidosis;
Conjunctivitis with Pseudomembrane
Epidemic keratoconjunctivitis (EKC), ligneous conjunctivitis (a rare idiopathic bilateral
Optometric Physician
Ligneous Conjunctivitis Treated with Topical Plasmin and Topical Plasminogen. ... Treatment
Search
Ligneous conjunctivitis: report of two cases. Abstract number: P1356. ... We report two
conjunctivitis
...associated hemorrhagic conjunctivitis. Amniotic membrane transplantation
MGI 3.0 - References Query Results (Details)
98139456 (MEDLINE). Title: Ligneous conjunctivitis in plasminogen-deficient
MGI 3.0 - References Query Results (Details)
9242524 (PubMed). Title: Homozygous mutations in the plasminogen gene
Ligneous conjunctivitis. Case report
Conjuntivitis lignea: a propósito de un caso. Ligneous conjunctivitis. Case
Plasminogen
Consider testing plasminogen in patients with ligneous conjunctivitis,
healthwise
None. General Discussion. Ligneous Conjunctivitis is a rare disorder that is characterized
Thrombosis and Haemostasis
Contraceptive pills induce an improvement in congenital hypoplasminogenemia in
Thrombosis and Haemostasis
Homozygous and Compound-heterozygous Type I Plasminogen Deficiency Is a Common
Health Library -
Conjunctivitis, Ligneous. ... Ligneous Conjunctivitis is a rare disorder that is characterized
Health Library -
Conjunctivitis, Ligneous. ... Ligneous Conjunctivitis is a rare disorder that is characterized
Allergic Conjunctivitis Clinical Resources
...document: Noninfectious Causes of Conjunctivitis: Access document;
Keratoconjunctivitis Clinical Resources
Ligneous Conjunctivitis: Access document. Acknowledgments: Access
Dictionary definition of LIGNEOUS CONJUNCTIVITIS
Dictionary definition of LIGNEOUS CONJUNCTIVITIS. Medical dictionary.
LISTSERV 1.8e
Ligneous Conjunctivitis: Re: Ligneous Conjunctivitis (29 lines) From:
LISTSERV 1.8e
Ligneous Conjunctivitis: Ligneous Conjunctivitis (39 lines) From: Steve
Conjunctivitis
...syphilis, Kawasaki disease; Thyroid disease, gout, carcinoid, sarcoidosis, psoriasis,
BJO -- MEIRE et al. 84 (10): 1203
Ligneous conjunctivitis is a rare chronic pseudomembranous conjunctivitis that
BJO -- Abstracts: Diamond et al. 75 (12): 753
753-754. ORIGINAL ARTICLES. Tranexamic acid-associated ligneous conjunctivitis
Blood -- Abstracts: Schuster et al. 90 (3): 958
Download to Citation Manager. RAPID COMMUNICATION. Homozygous Mutations in
Blood -- Abstracts: Drew et al. 91 (5): 1616
Ligneous Conjunctivitis in Plasminogen-Deficient Mice. AF Drew, AH Kaufman,
Human protein: Q15146 - Plasminogen precursor. EMBL Bioinformatic ...
Disease, defects in plg may be associated with ligneous conjunctivitis
Human protein: AAH60513 - Plasminogen. EMBL Bioinformatic ...
Disease, defects in plg may be associated with ligneous conjunctivitis
LIGNEOUS CONJUNKTIVITIS IN SEVERE TYP I PLASMINOGEN DEFICIENCY
J. Kraft 1 , P. Zeitler 2 , V. Schuster 2 , W. Waller 1. Ligneous conjunctivitis
conjunctivitis type
...http://omni.ac.uk/browse/mesh/detail/C0009763L0009 TYPE I PLASMINOGEN DEFICIENCY
NEJM -- Therapy with a Purified Plasminogen Concentrate in an ...
Article from The New England Journal of Medicine -- Therapy with a Purified Plasminogen
E-STREAMS Vol. 5, No. 12 - December 2002
Systemic Disease and Conjunctivitis 145; Superior Limbic Keratoconjunctivitis
VI Congreso Virtual Hispanoamericano de AnatomÃa Patológica
Scleral grafting in the management of ligneous conjunctivitis. ... 4. Nussgens
Ophthalmology, May 2002
Effective Treatment of Ligneous Conjunctivitis With Topical Plasminogen.
(read full article)
Sources on the web: CANCER-HELP.ORG
Related publications: CANCER-HELP.ORG
Related documents to download: -
Notes: -
Year: 2005
Title: LA CONGIUNTIVITE LIGNEA
Date: - (dd/mm/yy) - 01/01/06
Authors: Simona Sforzin
Abstract:
La
CONGIUNTIVITE LIGNEA
Definizione
La congiuntivite lignea è una rara congiuntivite cronica in cui una grossa massa nodulare sostituisce la normale mucosa. Possono venire coinvolte altre mucose come quella nasale, orale e del tratto genitale femminile (R.M. Winter, M. Baraitser, London Neurogenetics Database, Oxford Medical Databases, 2000). Di recente, si è visto che il deficit completo di plasminogeno spiega questa sindrome clinica distinta, che era appunto nota come congiuntivite lignea. Le manifestazioni principali sono oculari. (C. Scriver et al., The Metabolic and Molecular Bases of Inherited Disease, Eighth Edition).
Segni e Sintomi
L’omozigosi per la mutazione nulla nel plasminogeno fu individuata come la base molecolare di una rara malattia oftalmologica, la congiuntivite lignea. Questa malattia fu descritta per la prima volta nel 1847 e ne sono stati documentati più di cento casi. La congiuntivite lignea si presenta di solito nella prima infanzia come una congiuntivite cronica pseudomembranosa, sebbene in alcuni pazienti l’esordio sia ritardato fino all’età adulta. Queste lesioni hanno una consistenza che ricorda il legno, da cui il termine di “congiuntivite lignea” e possono prendere origine da traumi minori o da infezioni. Pseudomembrane simili possono insorgere in altre superfici mucose, compresa l’orofaringe, l’albero tracheobronchiale e il tratto genitale femminile. Una significativa minoranza di pazienti presenta idrocefalo congenito occlusivo. La maggior parte dei casi appare essere sporadica e, nel 1986, si è osservato un modello di ereditarietà coerente con un disordine autosomico recessivo. L’esame istologico delle pseudomembrane rivela rottura dell’epitelio e depositi massivi di fibrina accompagnati da un infiltrato infiammatorio. Nel 1997, Schuster et al. studiarono due pazienti con congiuntivite lignea ed una documentata attività plasmatica del plasminogeno non dosabile. Un paziente aveva omozigosi per Arg216Cys e l’altro per Trp597Ter. Il padre di quest’ultimo presentava una eterozigosi composta per questa mutazione non senso e una seconda mutazione nello stesso codone dell’altro allele, Trp597Cys, che portava ad una attività del plasminogeno ridotta al 15 percento. I livelli di plasminogeno negli altri genitori erano più o meno la metà del normale. Gli stessi autori, successivamente, descrissero altri 5 pazienti, con età tra i 5 e i 71 anni, tutti eterozigoti composti per mutazioni nel gene del plasminogeno. C’è una correlazione tra il tipo di mutazione, l’attività del plasminogeno residua e la gravità della malattia. La completa assenza di complicazioni tromboemboliche nei pazienti con congiuntivite lignea o nei loro familiari è in stridente contrasto con le scoperte realizzate nei topi con deficit di plasminogeno. Queste osservazioni suggeriscono che il ruolo primario del plasminogeno negli umani si giochi nella cleareance extravascolare della fibrina, implicando l’esistenza di un sistema di fibrinolisi intravascolare alternativo o sovrapposto. (C. Scriver et al., The Metabolic and Molecular Bases of Inherited Disease, Eighth Edition). L’esame istopatologico rivela depositi amorfi ed eosinofili di fibrina, albumina e globulina. Sono state viste cellule dell’infiammazione acuta e cronica. L’epitelio di rivestimento può essere ulcerato in alcuni punti o, più spesso, subire proliferazione iperplastica. I vasi sanguigni impermeabili possono essere un fattore nella patogenesi della malattia. (Albert and Jakobiec, Principles and Practice of Ophthalmology, Second Edition, Saunders).
Eziologia
L’ereditarietà è autosomica recessiva
Terapia
In un recente lavoro, un paziente con congiuntivite lignea grave (omozigote per Glu460Ter), è stato trattato con successo con un concentrato di Lys-plasminogeno preparato dal plasma umano. Questa terapia ha portato ad un rapido declino dei livelli di complesso trombina/antitrombina e di D-dimero e ad una risposta clinica drammatica. In questo paziente, la terapia sostitutiva a lungo termine con plasminogeno ha portato alla completa regressione della congiuntivite lignea ha normalizzato le secrezioni iperviscose del tratto respiratorio e le ferite guarite. La remissione dei sintomi con la terapia sostitutiva e la loro ricomparsa quando la terapia viene interrotta dimostra il ruolo cruciale del plasminogeno nella fibrinolisi extravascolare e conferma che la grave deficienza di plasminogeno causa la congiuntivite lignea. (Scott et al. Therapy with a Purified Plasminogen Concentrate in an Infant with Ligneous Conjunctivitis and Homozygous Plasminogen Deficiency. N Engl J Med 339:1679, 1999)
Bibliografia
Schuster-V; Zeitler-P; Seregard-S; Ozcelik-U; Anadol-D; Luchtman-Jones-L; Meire-F; Mingers-AM; Schambeck-C; Kreth-HW
Homozygous and compound-heterozygous type I plasminogen deficiency is a common cause of ligneous conjunctivitis
THROMBOSIS-AND-HAEMOSTASIS. JUN 2001; 85 (6) : 1004-1010
Martinovic-E; Ells-A
Ligneous conjunctivitis related to a defect in the fibrinolytic system
CANADIAN-JOURNAL-OF-OPHTHALMOLOGY-JOURNAL-CANADIEN-D-OPHTALMOLOGIE. APR 2001; 36 (3) : 147-149
Ploplis-VA
Gene targeting in hemostasis. Plasminogen
FRONTIERS-IN-BIOSCIENCE. MAR 2001; 6 : D555-D569
Ozcelik,-U; Akcoren,-Z; Anadol,-D; Kiper,-N; Orhon,-M; Gocmen,-A; Irkec,-M; Schuster,-V
Pulmonary involvement in a child with ligneous conjunctivitis and homozygous type I plasminogen deficiency.
Pediatr-Pulmonol. 2001 Aug; 32(2): 179-83
Martinovic,-E; Ells,-A
Ligneous conjunctivitis related to a defect in the fibrinolytic system.
Can-J-Ophthalmol. 2001 Apr; 36(3): 147-9
Shimabukuro,-M; Iwasaki,-N; Nagae,-Y; Nakagawa,-Y; Ohtori,-Y; Inoue,-Y; Tano,-Y
Ligneous conjunctivitis: a case report.
Jpn-J-Ophthalmol. 2001 Jul-Aug; 45(4): 375-7
Scully,-C; Gokbuget,-A-Y; Allen,-C; Bagan,-J-V; Efeoglu,-A; Erseven,-G; Flaitz,-C; Cintan,-S; Hodgson,-T; Porter,-S-R; Speight,-P
Oral lesions indicative of plasminogen deficiency (hypoplasminogenemia).
Oral-Surg-Oral-Med-Oral-Pathol-Oral-Radiol-Endod. 2001 Mar; 91(3): 334-7
Kraft,-J; Lieb,-W; Zeitler,-P; Schuster,-V
Ligneous conjunctivitis in a girl with severe type I plasminogen deficiency.
Graefes-Arch-Clin-Exp-Ophthalmol. 2000 Sep; 238(9): 797-800
Chen,-S; Wishart,-M; Hiscott,-P
Ligneous conjunctivitis: a local manifestation of a systemic disorder?
J--AAPOS. 2000 Oct; 4(5): 313-5
Inizio periodo consultato
Gennaio 2001
Ultimo aggiornamento
13/11/2001
Database
Medline Current Contents
Codici
icd9: - icd9cm: 372.10 - icd10: H10.4 - mim: #217090 - esenzione: RF0290
A cura di
Simona Sforzin
(read full article)
Sources on the web: MALATTIE RARE Regione Veneto
A cura di Simona Sforzin
Related publications: MALATTIE RARE Regione Veneto
A cura di Simona Sforzin
Related documents to download: -
Notes: -
Year: 2001
Title: PLASMINOGEN DEFICIENCY
Data Base: OMIM
By: DBGET
Date: - (dd/mm/yy) - 01/01/06
Authors: DBGET integrated database retrieval system, GenomeNet
Abstract: Database: OMIM
Entry: 173350
MIM Entry: 173350
Title:
+173350 PLASMINOGEN; PLG
PLASMINOGEN DEFICIENCY, INCLUDED;;
ANGIOSTATIN, INCLUDED;;
MICROPLASMIN, INCLUDED
Text:
Plasminogen is the zymogen in the circulating blood from which plasmin
is formed. Miyata et al. (1982) stated that plasminogen is a
single-chain glycoprotein with 790 amino acid residues. Activation to
the active form, plasmin, by urokinase (191840) involves cleavage at the
arg-val bond between residues 560 and 561, resulting in the formation of
the 2-chain plasmin molecule held together by 2 disulfide linkages. The
heavier chain contains about 411 residues and the lighter chain about
233. The main function of plasmin is the digestion of fibrin in blood
clots. Plasmin is a proteolytic enzyme with a specificity similar to
that of trypsin. Like trypsin, plasmin belongs to the family of serine
proteinases, in which the active site catalytic triad, his-57, asp-102,
and ser-195 (chymotrypsin numbering), is situated in the light chain.
The first abnormal plasminogen causing thrombophilia was reported by
Miyata et al. (1982); see 173350.0001. Hach-Wunderle et al. (1988) found
moderate deficiency of normal-functioning plasminogen in a 53-year-old
woman who developed deep venous thrombosis of the left thigh and calf,
following an injury to the leg. A similar deficiency of plasminogen was
found in the mother and a sister who, however, had no thrombotic
episodes. This was the only example of plasminogen deficiency among 435
German individuals with a history of thromboembolism who were evaluated
by Hach-Wunderle et al. (1988). Dysfunctional plasminogen variants were
also described by Wohl et al. (1982), Miyata et al. (1984), Kazama et
al. (1981), and Soria et al. (1983). In many of these cases the
plasminogen variant has been associated with a recurrent thrombosis.
Dolan et al. (1988) described 3 kindreds in which thrombosis was
associated with plasminogen deficiency of type I, i.e., immunoreactive
plasminogen levels were reduced in parallel with functional activity. In
1 woman they observed that plasminogen levels rose to within normal
limits during pregnancy and returned to low levels after delivery. In a
total of 8 pregnancies, no thrombotic events occurred. It is clear that
both type I and type II plasminogen deficiency predisposes to venous
thrombosis, although most of the hitherto reported cases have been of
type II, e.g., plasminogen Tochigi disease. Shigekiyo et al. (1992)
studied the frequency of thrombosis in 21 heterozygotes for type I
congenital PLG deficiency in 2 unrelated families. Three had had
thromboses, but analysis by the Kaplan-Meier method suggested no
difference in frequency from controls. Patrassi et al. (1993) found a
particular thrombotic-like retinal picture compatible with Coats disease
(see 300216) in a 17-year-old propositus in a kindred with heterozygous
plasminogen deficiency type I. Five of 13 family members from the
paternal side showed the same fibrinolytic defect. In 2 of these, a
history of recurrent phlebitis of the legs was present. No other family
members showed retinal abnormality.
Ligneous conjunctivitis (217090) is a serious complication of
plasminogen deficiency. In the tear fluid of the eye, plasminogen
activators released by the cornea (Mirshahi et al., 1996) convert the
zymogen plasminogen into the fibrinolytic enzyme plasmin, which rapidly
clears the cornea of fibrin deposits. The absence of plasmin activity
results in the formation of the fibrin-rich viscous or membranous
material typically seen in patients with ligneous conjunctivitis and in
mice with targeted disruption of the plasminogen gene (Drew et al.,
1998; Kao et al., 1998). An inflammatory reaction combined with
activation of inflammatory cells in fibroblasts, with a drying out of
the fibrin, results in the wood-like appearance of the conjunctival
lesions. In a double-gene knockout mouse model, the combination of
plasminogen deficiency and fibrinogen deficiency prevents corneal fibrin
deposits and associated inflammatory reactions and restores normal wound
healing. Tracheobronchial fibrin deposition has been observed in
combination with ligneous conjunctivitis in patients and in
plasminogen-deficiency mice (Ploplis et al., 1995). The fibrin deposits
impaired the ciliary system of the tracheobronchial tree and support
bacterial growth, predisposing the patient to multiple sinobronchial
infections. Involvement of the ear in patients with ligneous
conjunctivitis (Marcus et al., 1990) is attributable to fibrin
deposition in the middle ear. Internal hydrocephalus has been reported
in patients with ligneous conjunctivitis (e.g., by Schott et al., 1998),
and in plasminogen-deficient mice (Drew et al., 1998). The
pathophysiologic mechanism may be fibrin deposition in the cerebral
ventricular system, causing impaired circulation of the fluid in the
aqueduct region.
Strikingly, no intravascular thromboembolic episodes occur in ligneous
conjunctivitis (Schuster et al., 1997), despite a severe deficiency of
the key zymogen of the fibrinolytic system. Heterozygous plasminogen
deficiency also appears not to be a risk factor for thrombosis (Tait et
al., 1996; Shigekiyo et al., 1992), despite several reports to the
contrary.
Iijima et al. (1998) reported the case of a 49-year-old woman with
unilateral central retinal vein occlusion and ipsilateral cilioretinal
artery occlusion who showed familial dysplasminogenemia associated with
elevated lipoprotein(a). Decreased plasminogen activity without
reduction of plasminogen antigen was found in the patient, her 2 sibs,
and her 2 children.
Hobart (1978) identified a diallelic polymorphism of plasminogen with
gene frequencies about 0.7 and 0.3. Recombinants were found with HLA,
C3, C6 and ABO. Raum et al. (1979) could demonstrate no linkage with any
of 27 markers. Bissbort et al. (1983) found no linkage between PLG and
35 other marker genes. Although for the PLG:GC linkage, positive lod
scores (up to 1.52 at theta = 0.20) were found in females, negative lod
scores in males suggested caution in acceptance of this linkage as true.
The results were based on 18 families. Eiberg et al. (1984) found a lod
score of 7.37 at theta = 0.12 in males for linkage of FUCA2 and PLG.
Linkage of PLG with GC (and therefore location on chromosome 4) was
suggested by a lod score of 2.35 at theta 0.30 in males. Several studies
gave negative evidence on the possible chromosome 4 localization of the
PLG locus or, at best, weakly positive evidence (Falk and Huss, 1985;
Buetow et al., 1985; Marazita et al., 1985). Swisshelm et al. (1985),
using DNA probes for in situ mapping, located the PLG gene to 6q25-q27.
With a PLG-specific probe, Murray et al. (1985) did Southern blot
analyses of DNA from somatic hybrid cells and also localized the gene to
chromosome 6. Murray et al. (1987) observed linkage disequilibrium
between a newly identified DNA polymorphism and a previously described
protein polymorphism for plasminogen. The finding implied that the 2
types of polymorphisms described variation at the same locus. They
mapped the PLG locus to 6q26-q27 by study of somatic cell hybrids and by
in situ hybridization. By fluorescence in situ hybridization, Rao et al.
(1994) concluded that the PLG gene is located at 6q26. Degen et al.
(1990) isolated cDNA for the mouse gene and localized it to chromosome
17 of that species. Segregation of 2 allelic forms in 3 sets of
recombinant inbred strains allowed localization within the t-complex.
The gene was found to be deleted in the semidominant deletion mutant
'hairpintail.'
Studying a family affected by plasminogen deficiency and deep vein
thrombosis and performing haplotype analysis using RFLPs present in the
PLG and LPA genes, Magnaghi et al. (1995) discovered a recombination
event in a region of approximately 50 kb of DNA separating the 2 genes.
PCR and sequencing analysis of PLG exons 10 and 15, the sites of the 2
mutations found by Ichinose et al. (1991), revealed no abnormality,
suggesting that a new type of plasminogen mutation was present in this
Italian family. The mutation resulted in both plasminogen activity and
plasminogen antigen. The propositus had mild myocardial ischemia
documented by electrocardiography at the age of 29. He suffered a first
episode of proximal deep vein thrombosis and pulmonary embolism at the
age of 37 following a hip fracture which occurred in a car accident. A
brother suffered a lethal ischemic stroke at the age of 41.
Petersen et al. (1990) reported that the human plasminogen gene spans
about 52.5 kb of DNA and consists of 19 exons separated by 18 introns.
They concluded that there is at least one other plasminogen-related gene
in the human genome in addition to apolipoprotein(a) (152200). Forsgren
et al. (1987) characterized a full-length cDNA for plasminogen. Wu et
al. (1987) described the preparation and purification of a fully
functional human microplasmin derived from native plasmin. Wu et al.
(1987) determined the structure of microplasmin and proposed a scheme
for its formation.
In their Figure 3, Magnaghi et al. (1995) illustrated the orientation
and relative position of the LPA and PLG genes and the apo(a)-like and
plasminogen-like genes. The PLG and LPA genes are transcribed in
opposite directions.
O'Reilly et al. (1994) isolated from a Lewis lung carcinoma a novel
angiogenesis inhibitor that mediated the suppression of metastases by
this tumor and designated the inhibitor angiostatin. They found that
angiostatin is a 38-kD internal fragment of plasminogen containing at
least 3 of the kringles of plasminogen. Cao et al. (1996) demonstrated
that recombinant fragments of angiostatin have inhibitory activity in
vitro. Gately et al. (1996) showed that angiostatin is produced by the
proteolytic cleavage of plasminogen by a serine protease produced by
several human prostate carcinoma cell lines.
Fischer et al. (2000) identified plasminogen, a proprotease implicated
in neuronal excitotoxicity, as a PrPsc (176640)-binding protein. Binding
is abolished if the conformation of the PrPsc is disrupted by 6-molar
urea or guanidine. The isolated lysine-binding site-1 of plasminogen
(kringles I-III) retains this binding activity, and binding can be
competed for with lysine. Plasminogen does not bind to PrPc; thus
plasminogen represents the first endogenous factor discriminating
between normal and pathologic prion protein. Fischer et al. (2000)
suggested that this unexpected property may be exploited for diagnostic
purposes.
Schuster et al. (1999) found distinct compound heterozygous mutations in
the plasminogen gene in 5 patients with ligneous conjunctivitis. One
patient had a lys19-to-glu/arg216-to-his pair of mutations. The patient
was a previously healthy 71-year-old woman who had first developed
unilateral ligneous conjunctivitis at the age of 69 years. At that time
a pseudomembrane developed over the palpebral conjunctiva of the right
upper eyelid. It recurred rapidly after surgical removal.
Data on gene frequencies of allelic variants of plasminogen were
tabulated by Roychoudhury and Nei (1988).
ANIMAL MODEL
Bugge et al. (1995) reported that mice rendered Plg deficient by gene
targeting complete embryonic development, survive to adulthood, and are
capable of reproduction. They do, however, develop multiple spontaneous
thrombotic lesions leading to severe organ damage and high morbidity or
mortality at an early age. They noted that in the Plg -/- mice, the
levels of urokinase-type plasminogen activator in urine were normal.
Romer et al. (1995) analyzed skin wound repair in Plg knockout mice and
demonstrated that Plg is required for normal repair of skin wounds.
A number of studies have shown that gram-negative and gram-positive
bacteria can interact with the host plasminogen activation system to
increase their invasiveness and enhance their ability to cross tissue
barriers Boyle and Lottenberg (1997). Gebbia et al. (1999) studied the
role of the plasminogen activation system during the course of infection
of relapsing fever caused by a species of Borrelia in plasminogen
knockout mice, Plg -/-. Subcutaneous inoculation of spirochetes achieved
a similar peak spirochetemia in control and deficient mice, indicating
that the plasminogen activation system had no effect on the development
of this phase of the infection. Anemia, thrombocytopenia, hepatitis,
carditis, and splenomegaly were noted in all mice during and immediately
after peak spirochetemia. Fibrin deposition in organs was noted in Plg
-/- mice but not in controls. Significantly greater spirochetal DNA
burdens were consistently observed in the hearts and brains of control
mice 28 to 30 days after infection. Furthermore, the decreased
spirochetal load in brains of Plg -/- mice was associated with a
significant decrease in the degree of inflammation of the leptomeninges
in these mice. These findings indicated a role for the plasminogen
activation system in heart and brain invasion by relapsing fever
Borrelia, resulting in organ injury.
Cao et al. (1998) showed that a shift of balance of tumor angiogenesis
by gene transfer of a cDNA coding for mouse angiostatin into murine T241
fibrosarcoma cells suppresses primary and metastatic tumor growth in
vivo. Implementation of stable clones expressing mouse angiostatin in
C57B16/J mice inhibited primary tumor growth by an average of 77%. After
removal of primary tumors, the pulmonary micrometastases in
approximately 70% of mice remained in a microscopic dormant and
avascular state for 2 to 5 months. The tumor cells in the dormant
micrometastases exhibited a high rate of apoptosis balanced by a high
proliferation rate. These studies showed the diminished growth of lung
metastases after removal of the primary tumor, suggesting that
metastases are self-inhibitory by halting angiogenesis. The data may
also provide a novel approach for cancer therapy by antiangiogenic gene
therapy with a specific angiogenesis inhibitor. The angiostatin-induced
long-term dormancy of lung metastases was equivalent to 14 to 15 human
years (when 1 mouse day is equivalent to approximately 35 human days).
Drixler et al. (2001) examined the biologic effects of angiostatin on
pathologic and physiologic retinal angiogenesis as well as its effects
on growth and development in newborn mice. They found that angiostatin
successfully inhibited oxygen-induced intravitreal pathologic
angiogenesis without affecting the development of physiologic retinal
vascularization, development, and growth. Drixler et al. (2001)
concluded that antiangiogenic treatment might be a useful in
proliferative retinopathies.
Swaisgood et al. (2002) evaluated the in vivo effect of plasma
carboxypeptidase B (CPB2; 603101) on plasminogen function.
Cpb2-deficient mice, generated by homologous recombination, were healthy
and did not exhibit the poor health characteristics of Plg-deficient
mice. In a pulmonary clot lysis model, fibrinolysis was significantly
increased in mice with partial (Cpb2 +/-) or total (Cpb2 -/-) absence of
Cpb2 compared with their wildtype counterparts (Cpb2 +/+). In a
thioglycollate model of peritoneal inflammation, leukocyte migration at
72 hours increased significantly in Plg +/-/Cpb2 +/- and Plg +/-/Cpb2
-/- compared with their wildtype counterparts. The studies demonstrated
that Cpb2 regulates primary functions of Plg in fibrinolysis and cell
migration in vivo.
Allelic Variants:
.0001
THROMBOPHILIA DUE TO PLASMINOGEN TOCHIGI
PLASMINOGEN KAGOSHIMA;;
PLASMINOGEN NAGOYA II;;
PLG M5
PLG, ALA600THR
Aoki et al. (1978) investigated a patient with recurring thrombosis. The
only abnormality was depressed plasminogen activity in the plasma.
Plasminogen antigen concentration was normal, however. Studies of the
family showed others who, like the proband, had about half-normal
plasminogen activity and showed one person (both of whose parents were
apparent heterozygotes) who had no plasminogen activity despite normal
antigen levels. Gel electrofocusing of the purified plasminogen from
heterozygotes and the homozygote confirmed the existence of an
abnormality of the plasminogen molecule in this family. Miyata et al.
(1982) referred to the abnormal plasminogen in the family of Aoki et al.
(1978) as plasminogen Tochigi. They showed, furthermore, that the
abnormality is replacement of alanine by threonine as residue 600 in the
active site. (Ala-600 is the equivalent of ala-55 in the chymotrypsin
numbering system.) Presumably, the nucleotide change is CGX to TGX. The
authors suggested that threonine at position 55 in plasminogen Tochigi
may perturb his-57 such that the proton transfers associated with the
normal catalytic process cannot occur in the abnormal plasmin. Ichinose
et al. (1991) described the same mutation: an alanine at position 601
near the active site histidine was replaced by a threonine as a result
of a G-to-A transition. (Whether indicated as an ALA600THR or an
ALA601THR mutation depends on the method of counting codons.) The
mutation results in the loss of a Fnu4HI restriction endonuclease site;
Fnu4HI recognizes GCTGC but not ACTGC. Ichinose et al. (1991) observed a
homozygote.
By isoelectric focusing (IEF) electrophoresis, several workers
identified a functionally inactive PLG variant designated PLG M5,
present in 2 to 4% of Japanese subjects (review by Kikuchi et al.,
1992). Kikuchi et al. (1992) demonstrated that PLG Tochigi and PLG
Nagoya II are identical to PLG M5. The ala600-to-thr mutation is a type
I mutation; the plasma levels of immunoreactive PLG are normal but
activities are very low.
Murata et al. (1997) studied 3 patients with retinochoroidal vascular
disorders and found that each carried the ala601-to-thr mutation. They
suggested that this defect may play a role in the pathogenesis of
circulatory disorders in small local vessels because of reduced
fibrinolytic activity due to decreased functional plasminogen levels.
.0002
THROMBOPHILIA DUE TO PLASMINOGEN NAGOYA I
PLG, VAL355PHE
Ichinose et al. (1991) described a mutation of val355-to-phe resulting
from a guanine-to-thymine transversion. This mutation was demonstrated
by digestion with AvaII endonuclease, which recognizes the normal GGTCC
but not GTTCC.
.0003
THROMBOPHILIA DUE TO PLASMINOGEN DEFICIENCY
PLG, SER572PRO
In a 43-year-old Japanese woman with late-onset epilepsy as a result of
cerebral infarction associated with PLG deficiency, Azuma et al. (1993)
found heterozygosity for a TCC (ser)-to-CCC (pro) transition at codon
572 in exon 14. The patient and members of her family were heterozygous.
.0004
CONJUNCTIVITIS, LIGNEOUS
PLG, ARG216HIS
Ligneous conjunctivitis (217090) is a rare and unusual form of chronic
pseudomembranous conjunctivitis that usually starts in early infancy.
The disease may be associated with pseudomembranous lesions of other
mucous membranes in the mouth, nasopharynx, trachea, and female genital
tract. Schuster et al. (1997) examined 2 unrelated Turkish girls
suffering from ligneous conjunctivitis and occlusive hydrocephalus. Both
children exhibited severe plasminogen deficiency. Genomic DNA from both
parents as well as from clinically healthy family members were screened
for mutations in the plasminogen gene by PCR, SSCP analysis, and DNA
sequencing. In 1 girl with ligneous conjunctivitis, a homozygous G-to-A
point mutation was identified in plasminogen exon 7 at nucleotide
position 780, leading to an arg216-to-his amino acid exchange. Her
healthy sister and her healthy parents were heterozygous for this
mutation. The second patient showed homozygosity for a G-to-A point
mutation in plasminogen exon 15 at nucleotide position 1924, which led
to a stop codon (trp597 to ter; 173350.0005). The healthy parents were
shown to be heterozygous for this mutation. In addition, the father's
second allele revealed another mutation in the same codon (trp597 to
cys), indicating that he was a compound heterozygote at the plasminogen
locus.
In a previously healthy 71-year-old woman who had first developed
unilateral ligneous conjunctivitis at the age of 69 years, Schuster et
al. (1999) identified the R216H mutation and a lys19-to-glu mutation
(173350.0010) in compound heterozygous state.
.0005
CONJUNCTIVITIS, LIGNEOUS
PLG, TRP597TER
See 173350.0004 and Schuster et al. (1997).
.0006
CONJUNCTIVITIS, LIGNEOUS
PLG, GLU460TER
In a child of a consanguineous Turkish couple, Schott et al. (1998)
found ligneous conjunctivitis and homozygous plasminogen deficiency due
to homozygosity for a 1511G-T transversion, leading to a stop codon
(TAA) at position 460 (glu460 to ter). This mutation abolished the
catalytic domain of plasmin. A healthy brother and the healthy parents
were heterozygous for the mutation. Prenatal ultrasound examination
demonstrated progressive internal hydrocephalus, and the child was
delivered by elective cesarean section at a gestational age of 35 weeks.
Bulging fontanel and macrocephalus were the only findings at that time.
Bilateral inflammation of the palpebral portion of the conjunctiva, with
hypersecretion and formation of pseudomembranes, was noticed 3 days
after birth. Within 2 weeks, a thick, yellowish-white, fibrous, woody
pseudomembranous layer of conjunctival proliferation had developed,
spreading from the inner side of the upper and lower eyelids and
completely closing both eyes. The pseudomembranes were removed
surgically several times but regrew rapidly. Imaging studies
demonstrated Dandy-Walker malformation, hypoplasia of the cerebellum,
and hypoplastic corpus callosum. There was also hyperviscosity of
tracheobronchial and nasopharyngeal secretions and impaired wound
healing. Replacement therapy with lysine-conjugated plasminogen led to
rapid regression of the pseudomembranes and normalization of respiratory
tract secretions and wound healing.
.0007
PLASMINOGEN KANAGAWA-I
PLG, GLY732ARG
Higuchi et al. (1998) identified a new dysplasminogen, plasminogen
Kanagawa-I, in a healthy 20-year-old male with no past history of
thrombosis or bleeding. He was found to have dysplasminogenemia
following voluntary blood donation for teaching purposes. His plasma
plasminogen activity was approximately 50% of that of normal pooled
plasma. Nucleotide sequencing revealed a heterozygous G-to-A transition
in exon 18, which resulted in an amino acid substitution of gly732 to
arg. Both the proband's father and paternal grandfather were
heterozygous for this mutation. The grandfather was a compound
heterozygote for plasminogen Kanagawa-I and Tochigi (173350.0001); his
plasminogen activity and antigen levels were 7.7% and 87.2% of that of
normal pooled plasma, respectively. He had never had significant
thrombosis.
.0008
CONJUNCTIVITIS, LIGNEOUS
PLG, LYS212DEL
Schuster et al. (1999) described unusually severe ligneous
conjunctivitis with systemic manifestations in a brother and sister who
were compound heterozygotes for a deletion of lys212 of the PLG gene,
inherited from the mother, and a splice site mutation in intron Q,
namely a deletion of the first nucleotide, a guanosine, following exon
17 (173350.0009), inherited from the father. Both exhibited plasminogen
antigen and functional activity levels below the limit of detection.
The 19-year-old white female described by Schuster et al. (1999) first
developed conjunctivitis at 3 weeks of age. At 3 years of age, she
developed bilateral conjunctival pseudomembranes and was diagnosed with
ligneous conjunctivitis. These membranes recurred repeatedly,
necessitating surgical removal on 18 different occasions. The rate of
conjunctival membrane formation had decreased in recent years. At 5
years of age, she developed hoarseness and was noted to have a ligneous
membrane in the vocal cords. She also showed asthma-like symptoms. At
the age of 8 years, she developed pneumomediastinum and had her first of
20 bronchoscopies to remove thickened membranes from her
laryngotracheobronchial tree. At 16 years of age, she developed an
abscess of the left lung, necessitating bronchoscopic drainage. She had
also had gingival membranes and nodular, calcified masses in the renal
collecting system, demonstrable by ultrasound and pyelography. Treatment
with multiple eyedrops, corticosteroids, local heparin, and multiple
courses of various antibiotics had been ineffective.
The 14-year-old brother reported by Schuster et al. (1999) developed
conjunctivitis at 9 months of age that became severe at 4 years of age.
He had required surgery for ligneous conjunctival membranes on 15
occasions, beginning at the age of 5 years. Also since that age, he had
had membranes on the gums associated with intermittent bleeding,
geographic tongue, and sinusitis. He also had membrane formation in the
pharynx and in the renal collecting system. Furthermore, duodenal
ulceration and an eosinophilic gastric infiltration were observed. The
clinical course of these patients had previously been reported by
Bateman et al. (1986) and Cohen (1990).
.0009
CONJUNCTIVITIS, LIGNEOUS
PLG, IVS17, 1-BP DEL, G, +1
See 173350.0008 and Schuster et al. (1999).
.0010
CONJUNCTIVITIS, LIGNEOUS
PLG, LYS19GLU
See 173350.0004 and Schuster et al. (1999).
See Also:
Dayhoff (1972); Eiberg and Mohr (1982); Hobart (1979); Ikemoto et
al. (1982); Lewis et al. (1984); Mannucci et al. (1986); Nakamura
and Abe (1982); Nishigaki and Omoto (1982); Raum et al. (1980); Sakata
and Aoki (1980); Scharrer et al. (1986); Wu et al. (1987)
References:
1. Aoki, N.; Morio, M.; Sakata, Y.; Yoshida, N.: Abnormal plasminogen:
a hereditary molecular abnormality found in a patient with recurrent
thrombosis. J. Clin. Invest. 78: 1186-1195, 1978.
2. Azuma, H.; Uno, Y.; Shigekiyo, T.; Saito, S.: Congenital plasminogen
deficiency caused by a ser572-to-pro mutation. Blood 82: 475-480,
1993.
3. Bateman, J. B.; Pettit, T. H.; Isenberg, S. J.; Simons, K. B.:
Ligneous conjunctivitis: an autosomal recessive disorder. J. Pediat.
Ophthal. Strabismus 23: 137-140, 1986.
4. Bissbort, S.; Bender, K.; Mayerova, A.; Wienker, T. F.; Mauff,
G.: Genetic linkage relations of the human plasminogen gene. Hum.
Genet. 63: 126-131, 1983.
5. Boyle, M. D. P.; Lottenberg, R.: Plasminogen activation by invasive
human pathogens. Thromb. Haemost. 77: 1-10, 1997.
6. Buetow, K. H.; Murray, J. C.; Ferrell, R. E.: Linkage relationship
of PLG, GC and ALB. (Abstract) Cytogenet. Cell Genet. 40: 595-596,
1985.
7. Bugge, T. H.; Flick, M. J.; Daugherty, C. C.; Degen, J. L.: Plasminogen
deficiency causes severe thrombosis but is compatible with development
and reproduction. Genes Dev. 9: 794-807, 1995.
8. Cao, Y.; Ji, R. W.; Davidson, D.; Schaller, J.; Marti, D.; Sohndel,
S.; McCance, S. G.; O'Reilly, M. S.; Llinas, M.; Folkman, J.: Kringle
domains of human angiostatin: characterization of the anti-proliferative
activity on endothelial cells. J. Biol. Chem. 271: 29461-29467,
1996.
9. Cao, Y.; O'Reilly, M. S.; Marshall, B.; Flynn, E.; Ji, R.-W.; Folkman,
J.: Expression of angiostatin cDNA in a murine fibrosarcoma suppresses
primary tumor growth and produces long-term dormancy of metastases. J.
Clin. Invest. 101: 1055-1063, 1998.
10. Cohen, S. R.: Ligneous conjunctivitis: an ophthalmic disease
with potentially fatal tracheobronchial obstruction. Laryngeal and
tracheobronchial features. Ann. Otol. Rhinol. Laryng. 99: 509-512,
1990.
11. Dayhoff, M. O.: Atlas of Protein Sequence and Structure. Thrombin
and plasmin. Washington: National Biomedical Research Foundation
(pub.) 5: 1972. Pp. D100-D101 and D110.
12. Degen, S. J. F.; Bell, S. M.; Schaefer, L. A.; Elliott, R. W.
: Characterization of the cDNA coding for mouse plasminogen and localization
of the gene to mouse chromosome 17. Genomics 8: 49-61, 1990.
13. Dolan, G.; Greaves, M.; Cooper, P.; Preston, F. E.: Thrombovascular
disease and familial plasminogen deficiency: a report of three kindreds. Brit.
J. Haemat. 70: 417-421, 1988.
14. Drew, A. F.; Kaufman, A. H.; Kombrinck, K. W.; Danton, M. J.;
Daugherty, C. C.; Degen, J. L.; Bugge, T. H.: Ligneous conjunctivitis
in plasminogen-deficient mice. Blood 91: 1616-1624, 1998.
15. Drixler, T. A.; Borel Rinkes, I. H. M.; Ritchie, E. D.; Treffers,
F. W.; van Vroonhoven, T. J. M. V.; Gebbink, M. F. B. G.; Voest, E.
E.: Angiostatin inhibits pathological but not physiological retinal
angiogenesis. Invest. Ophthal. Vis. Sci. 42: 3325-3330, 2001.
16. Eiberg, H.; Mohr, J.: Linkage scores among GC, PLG, MNSs, PON,
and C3. (Abstract) Cytogenet. Cell Genet. 32: 270-271, 1982.
17. Eiberg, H.; Mohr, J.; Nielsen, L. S.: Linkage of plasma alpha-L-fucosidase
(FUCA2) and the plasminogen (PLG) system. Clin. Genet. 26: 23-29,
1984.
18. Falk, C. T.; Huss, J.: Estimates of recombination frequencies
between the chromosome 4 markers MN, GC, and PLG. (Abstract) Cytogenet.
Cell Genet. 40: 627, 1985.
19. Fischer, M. B.; Roeckl, C.; Parizek, P.; Schwarz, H. P.; Aguzzi,
A.: Binding of disease-associated prion protein to plasminogen. Nature 408:
479-483, 2000.
20. Forsgren, M.; Raden, B.; Israelsson, M.; Larsson, K.; Heden, L.-O.
: Molecular cloning and characterization of a full-length cDNA clone
for human plasminogen. FEBS Lett. 213: 254-260, 1987.
21. Gately, S.; Twardowski, P.; Stack, M. S.; Patrick, M.; Boggio,
L.; Cundiff, D. L.; Schnaper, H. W.; Madison, L.; Volpert, O.; Bouck,
N.; Enghild, J.; Kwaan, H. C.; Soff, G. A.: Human prostate carcinoma
cells express enzymatic activity that converts human plasminogen to
the angiogenesis inhibitor, angiostatin. Cancer Res. 56: 4887-4890,
1996.
22. Gebbia, J. A.; Monco, J. C. G.; Degen, J. L.; Bugge, T. H.; Benach,
J. L.: The plasminogen activation system enhances brain and heart
invasion in murine relapsing fever borreliosis. J. Clin. Invest. 103:
81-87, 1999.
23. Hach-Wunderle, V.; Scharrer, I.; Lottenberg, R.: Congenital deficiency
of plasminogen and its relationship to venous thrombosis. Thromb.
Haemost. 59: 277-280, 1988.
24. Higuchi, Y.; Furihata, K.; Ueno, I.; Ishikawa, S.; Okumura, N.;
Tozuka, M.; Sakurai, N.: Plasminogen Kanagawa-I, a novel missense
mutation, is caused by the amino acid substitution G732R. Brit. J.
Haemat. 103: 867-870, 1998.
25. Hobart, M. J.: Personal Communication. Cambridge, England
1978.
26. Hobart, M. J.: Genetic polymorphism of human plasminogen. Ann.
Hum. Genet. 42: 419-423, 1979.
27. Ichinose, A.; Espling, E. S.; Takamatsu, J.; Saito, H.; Shinmyozu,
K.; Maruyama, I.; Petersen, T. E.; Davie, E. W.: Two types of abnormal
genes for plasminogen in families with a predisposition for thrombosis. Proc.
Nat. Acad. Sci. 88: 115-119, 1991.
28. Iijima, H.; Gohdo, T.; Tsukahara, S.: Familial dysplasminogenemia
with central retinal vein and cilioretinal artery occlusion. Am.
J. Ophthal. 126: 312-314, 1998.
29. Ikemoto, S.; Sakata, Y.; Aoki, N.: Genetic polymorphism of human
plasminogen in a Japanese population. Hum. Hered. 32: 296-297, 1982.
30. Kao, W. W.; Kao, C. W.; Kaufman, A. H.; Kombrinck, K. W.; Converse,
R. L.; Good, W. V.; Bugge, T. H.; Degen, J. L.: Healing of corneal
epithelial defects in plasminogen- and fibrinogen-deficient mice. Invest.
Ophthal. Vis. Sci. 39: 502-508, 1998.
31. Kazama, M.; Tahara, C.; Suzuki, Z.; Gohchi, K.; Abe, T.: Abnormal
plasminogen, a case of recurrent thrombosis. Thromb. Res. 21: 517-522,
1981.
32. Kikuchi, S.; Yamanouchi, Y.; Li, L.; Kobayashi, K.; Ijima, H.;
Miyazaki, R.; Tsuchiya, S.; Hamaguchi, H.: Plasminogen with type-I
mutation is polymorphic in the Japanese population. Hum. Genet. 90:
7-11, 1992.
33. Lewis, M.; Kaita, H.; Philipps, S.; Giblett, E. R.; Anderson,
J.: Linkage data for the locus pairs PLG:GC and PLG:MN/Ss. (Abstract) Cytogenet.
Cell Genet. 37: 522, 1984.
34. Magnaghi, P.; Agazzi, A.; Semino, O.; Ferrari, M.; Barbui, T.;
D'Angelo, A.; Taramelli, R.: A recombination event in the closely
linked plasminogen and apolipoprotein(a) gene loci. Clin. Genet. 47:
285-289, 1995.
35. Mannucci, P. M.; Kluft, C.; Traas, D. W.; Seveso, P.; D'Angelo,
A.: Congenital plasminogen deficiency associated with venous thromboembolism:
therapeutic trial with stanozolol. Brit. J. Haemat. 63: 753-759,
1986.
36. Marazita, M. L.; Spence, M. A.; Boustany, R.-M.; Fleishnick, E.;
Martin, J. B.; Kolodny, E. H.: Linkage relations of PLG (plasminogen).
(Abstract) Cytogenet. Cell Genet. 40: 689, 1985.
37. Marcus, D. M.; Walton, D.; Donshik, P.; Choo, L.; Newman, R. A.;
Albert, D. M.: Ligneous conjunctivitis with ear involvement. Arch.
Ophthal. 108: 514-519, 1990.
38. Mirshahi, S.; Soria, J.; Nelles, L.; Soria, C.; Faure, J. P.;
Pouliguen, Y.; Mirshahi, M.: Plasminogen activators in human corneal
fibroblasts: secretion, cellular localization, and regulation. Fibrinolysis 10:
255-262, 1996.
39. Miyata, T.; Iwanaga, S.; Sakata, Y.; Aoki, N.: Plasminogen Tochigi:
inactive plasmin resulting from replacement of alanine-600 by threonine
in the active site. Proc. Nat. Acad. Sci. 79: 6132-6136, 1982.
40. Miyata, T.; Iwanaga, S.; Sakata, Y.; Aoki, N.; Takamatsu, J.;
Kamiya, T.: Plasminogens Tochigi II and Nagoya: two additional molecular
defects with Ala-600-Thr replacement found in plasmin light chain
variants. J. Biochem. 96: 277-287, 1984.
41. Murata, M.; Ooe, A.; Izumi, T.; Nakagawa, M.; Takahashi, S.; Ishikawa,
M.; Mori, K.; Ichinose, A.: Ala601-to-thr type dysplasminogenaemia
genetically diagnosed in patients with retinochoroidal vascular disorders. Brit.
J. Haemat. 99: 301-303, 1997.
42. Murray, J. C.; Buetow, K. H.; Donovan, M.; Hornung, S.; Motulsky,
A. G.; Disteche, C.; Dyer, K.; Swisshelm, K.; Anderson, J.; Giblett,
E.; Sadler, E.; Eddy, R.; Shows, T. B.: Linkage disequilibrium of
plasminogen polymorphisms and assignment of the gene to human chromosome
6q26-6q27. Am. J. Hum. Genet. 40: 338-350, 1987.
43. Murray, J. C.; Sadler, E.; Eddy, R. L.; Shows, T. B.; Buetow,
K. H.: Evidence for assignment of plasminogen (PLG) to chromosome
6, not chromosome 4. (Abstract) Cytogenet. Cell Genet. 40: 709,
1985.
44. Nakamura, S.; Abe, K.: Genetic polymorphism of human plasminogen
in the Japanese population: new plasminogen variants and relationship
between plasminogen phenotypes and their biological activities. Hum.
Genet. 60: 57-59, 1982.
45. Nishigaki, T.; Omoto, K.: Genetic polymorphism of human plasminogen
in Japanese: correspondence of alleles thus far reported in Japanese
and difference of activity among phenotypes. Jpn. J. Hum. Genet. 27:
341-348, 1982.
46. O'Reilly, M. S.; Holmgren, L.; Shing, Y.; Chen, C.; Rosenthal,
R. A.; Moses, M.; Lane, W. S.; Cao, Y.; Sage, E. H.; Folkman, J.:
Angiostatin: a novel angiogenesis inhibitor that mediates the suppression
of metastases by a Lewis lung carcinoma. Cell 79: 315-328, 1994.
47. Patrassi, G. M.; Sartori, M. T.; Piermarocchi, S.; Viero, M.;
Boeri, G.; Girolami, A.: Unusual thrombotic-like retinopathy (Coats'
disease) associated with congenital plasminogen deficiency type I. J.
Intern. Med. 234: 619-623, 1993.
48. Petersen, T. E.; Martzen, M. R.; Ichinose, A.; Davie, E. W.:
Characterization of the gene for human plasminogen, a key proenzyme
in the fibrinolytic system. J. Biol. Chem. 265: 6104-6111, 1990.
49. Ploplis, V. A.; Carmeliet, P.; Vazirzadeh, S.; Van Vlaenderen,
I.; Moons, L.; Plow, E. F.; Collen, D.: Effects of disruption of
the plasminogen gene on thrombosis, growth, and health in mice. Circulation 92:
2585-2593, 1995.
50. Rao, P. H.; Murty, V. V. V. S.; Gaidano, G.; Hauptschein, R.;
Dalla-Favera, R.; Chaganti, R. S. K.: Subregional mapping of 8 single
copy loci to chromosome 6 by fluorescence in situ hybridization. Cytogenet.
Cell Genet. 66: 272-273, 1994.
51. Raum, D.; Marcus, D.; Alper, C. A.: Genetic polymorphism of human
plasminogen. Am. J. Hum. Genet. 32: 681-689, 1980.
52. Raum, D.; Marcus, D.; Alper, C. A.: Genetic control of human
plasminogen (Plgn). (Abstract) Clin. Res. 27: 458A, 1979.
53. Romer, J.; Bugge, T. H.; Pyke, C.; Lund, L. R.; Flick, M. J.;
Degen, J. L.; Dano, K.: Impaired wound healing in mice with a disrupted
plasminogen gene. Nature Med. 2: 287-292, 1995.
54. Roychoudhury, A. K.; Nei, M.: Human Polymorphic Genes: World
Distribution. New York: Oxford Univ. Press (pub.) 1988.
55. Sakata, Y.; Aoki, N.: Molecular abnormality of plasminogen. J.
Biol. Chem. 255: 5442-5447, 1980.
56. Scharrer, I. M.; Wohl, R. C.; Hach, V.; Sinio, L.; Boreisha, I.;
Robbins, K. C.: Investigation of a congenital abnormal plasminogen,
Frankfurt I, and its relationship to thrombosis. Thromb. Haemost. 55:
396-401, 1986.
57. Schott, D.; Dempfle, C.-E.; Beck, P.; Liermann, A.; Mohr-Pennert,
A.; Goldner, M.; Mehlem, P.; Azuma, H.; Schuster, V.; Mingers, A.-M.;
Schwarz, H. P.; Kramer, M. D.: Therapy with a purified plasminogen
concentrate in an infant with ligneous conjunctivitis and homozygous
plasminogen deficiency. New Eng. J. Med. 339: 1679-1686, 1998.
58. Schuster, V.; Mingers, A.-M.; Seidenspinner, S.; Nussgens, Z.;
Pukrop, T.; Kreth, H. W.: Homozygous mutations in the plasminogen
gene of two unrelated girls with ligneous conjunctivitis. Blood 90:
958-966, 1997.
59. Schuster, V.; Seidenspinner, S.; Zeitler, P.; Escher, C.; Pleyer,
U.; Bernauer, W.; Stiehm, E. R.; Isenberg, S.; Seregard, S.; Olsson,
T.; Mingers, A.-M.; Schambeck, C.; Kreth, H. W.: Compound-heterozygous
mutations in the plasminogen gene predispose to the development of
ligneous conjunctivitis. Blood 93: 3457-3466, 1999.
60. Shigekiyo, T.; Uno, Y.; Tomonari, A.; Satoh, K.; Hondo, H.; Ueda,
S.; Saito, S.: Type I congenital plasminogen deficiency is not a
risk factor for thrombosis. Thromb. Haemost. 67: 189-192, 1992.
61. Soria, J.; Soria, C.; Bertrand, O.; Dunn, F.; Drouet, L.; Caen,
J. P.: Plasminogen Paris I: congenital abnormal plasminogen and its
incidence to thrombosis. Thromb. Res. 32: 229-238, 1983.
62. Swaisgood, C. M.; Schmitt, D.; Eaton, D.; Plow, E. F.: In vivo
regulation of plasminogen function by plasma carboxypeptidase B. J.
Clin. Invest. 110: 1275-1282, 2002.
63. Swisshelm, K.; Dyer, K.; Sadler, E.; Disteche, C.: Localization
of the plasminogen gene (PLG) to the distal portion of the long arm
of human chromosome 6 by in situ hybridization. (Abstract) Cytogenet.
Cell Genet. 40: 756, 1985.
64. Tait, R. C.; Walker, I. D.; Conkie, J. A.; Islam, S. I.; McCall,
F.: Isolated familial plasminogen deficiency may not be a risk factor
for thrombosis. Thromb. Haemost. 76: 1004-1008, 1996.
65. Wohl, R. C.; Summaria, L.; Chediak, J.; Rosenfeld, S.; Robbins,
K. C.: Human plasminogen variant Chicago III. Thromb. Haemost. 48:
146-152, 1982.
66. Wu, H.-L.; Shi, G.-Y.; Bender, M. L.: Preparation and purification
of microplasmin. Proc. Nat. Acad. Sci. 84: 8292-8295, 1987.
67. Wu, H.-L.; Shi, G.-Y.; Wohl, R. C.; Bender, M. L.: Structure
and formation of microplasmin. Proc. Nat. Acad. Sci. 84: 8793-8795,
1987.
Clinical Synopsis:
Heme:
Decreased digestion of fibrin in blood clots
Vascular:
Deep venous thrombosis;
Thromboembolism
Eyes:
Retinal thrombosis
Neuro:
Late-onset seizures due to cerebral infarction (e.g. .0003)
Lab:
Plasminogen deficiency
Inheritance:
Autosomal dominant (6q26)
Contributors:
Denise L. M. Goh - updated: 1/6/2003
Jane Kelly - updated: 6/21/2002
Ada Hamosh - updated: 12/1/2000
Victor A. McKusick - updated: 1/7/2000
Victor A. McKusick - updated: 7/13/1999
Victor A. McKusick - updated: 6/7/1999
Victor A. McKusick - updated: 3/3/1999
Victor A. McKusick - updated: 2/2/1999
Victor A. McKusick - updated: 12/4/1998
Victor A. McKusick - updated: 4/13/1998
Victor A. McKusick - updated: 9/5/1997
Victor A. McKusick - updated: 6/19/1997
Moyra Smith - updated: 3/20/1996
Moyra Smith - updated: 3/19/1996
Creation Date:
Victor A. McKusick: 6/2/1986
Edit Dates:
tkritzer: 01/20/2005
carol: 3/17/2004
carol: 2/5/2003
carol: 1/6/2003
carol: 6/24/2002
terry: 6/21/2002
carol: 12/1/2000
mcapotos: 7/25/2000
mgross: 6/29/2000
terry: 1/7/2000
mgross: 11/4/1999
carol: 7/23/1999
jlewis: 7/21/1999
terry: 7/13/1999
mgross: 6/21/1999
mgross: 6/15/1999
terry: 6/9/1999
terry: 6/7/1999
carol: 3/5/1999
terry: 3/3/1999
carol: 2/15/1999
terry: 2/2/1999
carol: 12/8/1998
terry: 12/4/1998
terry: 7/24/1998
carol: 4/13/1998
terry: 3/30/1998
terry: 9/12/1997
terry: 9/5/1997
jenny: 6/27/1997
alopez: 6/23/1997
jenny: 6/23/1997
mark: 6/19/1997
terry: 6/14/1996
mark: 3/20/1996
mark: 3/19/1996
mark: 9/18/1995
mimadm: 1/14/1995
davew: 8/5/1994
jason: 6/28/1994
warfield: 4/12/1994
carol: 2/21/1994
OMIM
(read full article)
Sources on the web: DBGET integrated database retrieval system, GenomeNet
Related publications: DBGET integrated database retrieval system, GenomeNet
Related documents to download: -
Notes:
Year: 2005
Title: Coagulation 24 July 2005 (c) 2005, PathologyOutlines.com, LLC
Date: - (dd/mm/yy) - 01/01/06
Authors: PatologyOutLines.Com
http://www.pathologyoutlines.com/
Printer Friendly Version
Abstract:
Coagulation
24 July 2005 (c) 2005, PathologyOutlines.com, LLC
Home Page
Printer Friendly Version
Bold and underlined topics are hypertext links within this document or to references
Table of Contents-Coagulation
Primary references, hemostasis-general, normal hemostasis, intrinsic pathway, extrinsic pathway, common pathway, protein C/S, thrombomodulin, antithrombin, fibrinolysis pathway, contact system
Bleeding disorders: general, laboratory approach
Acquired bleeding disorders: acute phase reaction, acquired dysfibrinogenemia, acquired von Willebrand’s disease, amyloidosis, bovine coagulation factor inhibitors, DIC, factor V inhibitor, factor VIII inhibitor, factor IX inhibitor, liver dysfunction, lupus anticoagulants, proteinuria, Vitamin K deficiency/coumadin
Hereditary bleeding disorders: general, algorithm for workup, factor I (fibrinogen) deficiency, factor II (prothrombin) deficiency, factor V deficiency, factor VII deficiency, factor VIII deficiency (hemophilia A), factor IX deficiency (hemophilia B), factor X deficiency, factor XI deficiency, factor XII deficiency, factor XIII deficiency, high molecular weight kininogen deficiency, prekallikrein deficiency, von Willebrand’s disease
Therapy related coagulopathies: coumadin / warfarin, danaparoid, heparin, heparin-low molecular weight, hirudin, thrombolytic therapy
Acquired thrombophilia / hypercoagulopathies: general, antiphospholipid antibodies, heparin induced thrombocytopenia
Hereditary thrombophilia / hypercoagulopathies: general, activated protein C resistance / factor V Leiden, antithrombin deficiency, dysfibrinogenemia, elevated coagulation factors, heparin cofactor II deficiency, hyperhomocysteinemia, protein C deficiency, protein S deficiency, prothrombin gene mutation (G20210A), sickle cell disease
Coagulation laboratory tests: general, quality assurance, abnormal PT and PTT, activated clotting time, activated protein C resistance, anticardiolipin antibodies, antiplasmin, antithrombin, bleeding time, clot retraction, cryofibrinogen, D-dimer, factor assays, factor I (fibrinogen) assay, factor V Leiden, factor VII assay, factor VIII assay, factor VIII inhibitor, factor IX assay, factor Xa assay, factor XI assay, factor XIII assay, heparin induced thrombocytopenia, heparinase, high molecular weight kininogen, homocysteine, hypercoagulation panel, INR, International sensitivity index, low molecular weight heparin, lupus anticoagulant, mixing studies, plasminogen assay, plasminogen activator antigen-1, platelet aggregation studies, platelet antibodies, platelet hyperaggregation studies, prekallikrein assay, protein C assays, protein S assays, prothrombin gene 20210A, PT, PTT, reptilase time, thrombin time, tPA, vWF testing-general, vWF antigen analysis, vWF activity, vWF multimer analysis
Primary references
Archives of Pathology and Laboratory Medicine (Archives), January 1976 to July 2005
CAP Today, January 2000 to June 2005
Journal of Clinical Pathology, January 2001 to July 2005
Henry: Clinical Diagnosis and Management by Laboratory Methods, 2001 (20th edition)
Massachusetts General Hospital coagulation handbook
Journal search terms: coagulation
Please refer to these primary references for more detailed discussions and photographs
Hemostasis-general
Involves formation of blood clots to stop bleeding from damaged vessels, and activation of natural anticoagulation and fibrinolytic systems to limit clot formation to sites of injury
Bleeding disorders are due to defects in clot formation or overactive fibrinolytic systems
Hypercoagulability disorders are due to defects in anticoagulant system or underactive fibrinolytic systems
Normal hemostasis
Initial step is formation of platelet plug to stop bleeding from damaged vessel
Then, platelet plug is reinforced by fibrin clot
Then, fibrin clot is stabilized by activated factor XIII, which cross-links fibrin strands
Fibrin clot occurs via either intrinsic or extrinsic pathway (or both)
Coagulation factors in intrinsic or extrinsic pathway assemble on surface of activated platelets, which are usually at site of vascular injury
Many coagulation reactions also require calcium as a cofactor
Note: “a” after factor number indicates “activated”
Factor I: fibrinogen
Factor II: prothrombin
Factor III: tissue thromboplastin (tissue factor)
Factor IV: ionized calcium
Factor V: occasionally called labile factor or proaccelerin
Factor VI: unassigned
Factor VII: occasionally called stable factor or proconvertin
Factor VIII: antihemophilic factor
Factor IX: plasma thromboplastin component, Christmas factor
Factor X: occasionally called Stuart-Prower factor
Factor XI: occasionally called plasma thromboplastin antecedent
Factor XII: Hageman factor
Factor XIII: fibrin-stabilizing factor
Intrinsic pathway
Involves factors VIII, IX, XI, XII (Hageman factor), prekallikrein, high molecular weight kininogen
Merges with extrinsic pathway into common pathway
Activated when factor XII binds to negatively charged “foreign” surface exposed to blood
Then sequentially activates factors XI, IX, X, then factor II (prothrombin to thrombin), which converts fibrinogen to fibrin (see common pathway, below)
Once extrinsic pathway is inhibited by TFPI-Xa complex (see extrinsic pathway), factor VIIIa / IXa complex becomes dominant generator of factor Xa, thrombin and fibrin
Factor XIIa also converts prekallikrein to kallikrein, which activates more factor XIIa; both require high molecular weight kininogen as cofactors
Kallikrein also releases bradykinin from high molecular weight kininogen, which causes vasoconstriction
Extrinsic pathway
Involves tissue factor (TF, factor III), originally considered “extrinsic” to blood since it is present on cell surfaces not normally in contact with (i.e. extrinsic to) the circulatory system
Believed to be the primary mechanism of coagulation pathway in vivo, as tissue factor binds to factor VII or activated factor VII (factor VIIa)
TF-Factor VIIa complex activates factors X and IX
Activated factor IX activates more factor X, with cofactors activated factor VIII, anionic phospholipids (from activated platelets) and calcium
Activated factor X converts prothrombin to thrombin, with activated factor V, anionic phospholipids (from activated platelets) and calcium as cofactors; prothrombin factor 1.2 is released (see common pathway, below)
After initial activation, pathway is inhibited by the binding of tissue factor pathway inhibitor (TFPI) to factor Xa, which inhibits TF-Factor VIIa complex, and further coagulation is dependent on the intrinsic pathway
Merges with extrinsic pathway into common pathway
Common pathway
Involves fibrinogen (factor I), factors II (prothrombin), V, X
Thrombin converts soluble fibrinogen to insoluble fibrin; releases fibrinopeptides A and B; remaining fibrin monomers polymerize to form fibrin; thrombin also binds to antithrombin, which inhibits thrombin to prevent excessive clotting
Thrombin may also activate factor XI (part of intrinsic pathway), factors V, VIII, XIII, XI and platelets
Factor XIII cross links fibrin to increase stability of fibrin clot
Protein C / Protein S anticoagulant pathway
Pathway is a physiologic anticoagulant system to limit blood clot formation (i.e. fibrinogen to fibrin conversion) to site of vessel injury
Major anticoagulant systems are protein C and protein S, antithrombin and tissue factor pathway inhibitor (TFPI, see Extrinsic pathway above)
Protein C and S: vitamin K dependent anticoagulant proteins produced mainly in liver (“C” because was third peak to elute from a diethylaminoethyl affinity column)
Activation: endothelial cell protein C receptor binds thrombin-thrombomodulin complex, which activates protein C, which binds to free protein S on endothelial or platelet phospholipids surfaces; this protein C / protein S complex degrades factors Va and VIIIa, which reduces fibrin formation
Activated protein C also indirectly promotes fibrinolysis
60-70% of protein S is bound to and inactivated by C4b binding protein, an acute phase reactant
References: Archives 2002;126:1337
Thrombomodulin
Intrinsic membrane glycoprotein on luminal surface of endothelial cells that binds thrombomodulin and facilitates the activation of protein C
C/T dimorphism at nucleotide 1418 is associated with premature myocardial infarction, but no definite association with venous thromboembolism
References: BMC Neurology 2004;4:21
Antithrombin
Formerly called antithrombin III
Functions as anticoagulant by inhibiting activated factors II (thrombin), IX, X, XI, XII, kallikrein, plasmin and probably factor VII
Activity is accelerated 1000x by interaction with heparin or heparan sulfate (located on endothelial cells)
Member of serine protease inhibitor (serpin) gene family on #1q23-25
References: Archives 2002;126:1326
Fibrinolysis pathway
Process of degrading the fibrin clot when it is no longer needed
Also prevents extension of clot beyond site of injury
Initiated by tPA (tissue plasminogen activator) or uPA (urokinase-like plasminogen activator), which convert plasminogen to plasmin in the presence of fibrin by cleaving the Arg561-Val562 peptide bond
Plasmin degrades the fibrin clot and intact fibrinogen to soluble fibrin/fibrinogen degradation products (FDP)
Plasmin also inactivates factors Va and VIIIa (as does Protein C and Protein S)
tPA is produced by endothelial cells; its activation of plasminogen is major mechanism for lysis of fibrin clots
uPA is produced by urine and plasma; keeps renal tracts free of blood clots; also is important for other cell surfaces and initiating nonfibrinolytic activities of plasmin
Excessive fibrinolysis is prevented by plasmin inhibitor (antiplasmin, formerly called alpha2-antiplasmin) and plasminogen activator inhibitor 1 (PAI-1, inhibits tPA and uPA)
PAI-1 is synthesized by hepatocytes and endothelial cells, is present in platelets and plasma; can bind to fibrin and inhibit plasminogen activators tPA and uPA
Homozygous deficiency of plasminogen is associated with ligneous conjunctivitis (rare form of chronic pseudomembranous conjunctivitis), and replacement therapy with plasminogen is therapeutic
Neither plasminogen deficiency (0.5 to 2.0% of patients with thrombosis) nor tPA are associated with increased risk of thrombosis
References: Archives 2002;126:1376
Contact System
Consists of unknown coagulation factors in the 1950’s
Includes factor XII (Hageman factor), prekallikrein (PK; Fletcher factor), high molecular weight kininogen (Williams, Flaujeac or Fitzgerald factor); some authors include factor XI
Made in the liver
Decreased activity is associated with liver disease, hepatic immaturity in newborns, antiphospholipid syndrome, Asian descent (for factor XII)
Homozygous deficiencies are rare, autosomal recessive; cause very long PTT but no bleeding disorders and no definite association with hypercoagulability
Recommended to not measure their activity in routine evaluation of patients with arterial or venous thromboembolism or acute coronary syndromes (Archives 2002;126:1382)
Laboratory testing: homozygous deficiencies cause prolonged PTT; heterozygous deficiencies have near normal PTT; the test for a particular contact factor is based on the ability of the patient’s plasma to correct a prolonged PTT in plasma that is deficient in the factor being tested
Bleeding disorders
Bleeding disorders - general
Clinical history is important:
(a) single site (structural lesion) vs. multiple sites (coagulopathy)
(b) for coagulopathies - hereditary (family history of bleeding or bleeding since childhood) or acquired (no previous bleeding history)
(c) time from “hemostasis challenge” to bleeding symptoms - immediate suggests platelet disorder (inability to form normal platelet plug); late suggests coagulopathy (breakthrough bleeding occurs after platelet plug due to impaired fibrin formation)
(d) physical exam: petechiae (platelet disorders) vs. hematoma or hemarthrosis (coagulation defects) vs. mucous membrane bleeding or bruising (nonspecific)
Bleeding disorders - laboratory approach
Laboratory tests should be ordered if (a) history or physical exam is suspicious for bleeding disorder or (b) for routine preoperative testing (PT, PTT, platelet count)
See algorithms for prolonged PT, prolonged PTT, abnormal platelet count (platelet chapter) or hereditary bleeding disorder (PT, PTT, and platelet count normal)
Acquired bleeding disorders
Acute phase reaction
Many serum proteins become elevated due to illness, injury, inflammation or stress; also pregnancy
Elevated levels return to normal after condition resolves
Causes increase in fibrinogen, factor VIII, vWF (up to 3x normal levels), decrease in PTT, decrease in protein S
Acquired dysfibrinogenemia
Usually caused by liver or biliary tract disease, acute phase reaction, hepatocellular carcinoma or renal cell carcinoma
Due to increased sialylation of fibrinogen’s carbohydrate side changes; this increases its net negative charge, which promotes charge repulsion between fibrin monomers and decreases the rate of fibrin polymerization
Tumor cells may secrete abnormal fibrinogen
Usually does not cause bleeding or thrombosis
Acquired von Willebrand’s disease
Rare, either spontaneous or associated with hematologic neoplasms or autoimmune disorders
Amyloidosis
Primary amyloidosis may cause acquired factor X deficiency due to the binding of amyloid to factor X
Also inhibits fibrinogen conversion to fibrin, causing prolongation of thrombin time and reptilase time
Bovine coagulation factor inhibitors
After use of bovine “fibrin glue” to achieve hemostasis, 1.7% develop a clinically significant inhibitor
Fibrin glue is bovine thrombin and cryoprecipitate (containing human fibrinogen)
Antibodies are formed against bovine thrombin, also against bovine factors V, VII, X (Archives 1998;122:887)
Disseminated intravascular coagulation (DIC)
Common, due to massive tissue injury, sepsis or other excessive activation of coagulation system; also pregnancy complications (abruptio placenta, amniotic fluid embolism, acute fatty liver of pregnancy, septic abortion), acute hemolytic transfusion reaction, snake bites, homozygous protein C deficiency, adult respiratory distress syndrome and hyaline membrane disease; chronic causes are cancer, liver disease, aortic aneurysm, retained dead fetus or giant hemangioma
Anticoagulant and fibrinolytic systems are activated and overwhelmed, leading to disseminated microthrombi and tissue ischemia, variable bleeding, and consumption of platelets, coagulation factors and natural anticoagulants
With malignancy, may get large vessel thrombosis
Activation of fibrinolytic system causes plasmin activation and formation of D-dimers and other fibrin degradation products
Schistocytes (fragmented red blood cells) are formed as red blood cells are severed flowing through fibrin strands
Laboratory: elevated D-dimers and other fibrin degradation products (FDPs), prolonged PT (70% of cases) and PTT (50%), decreasing platelets and fibrinogen (50%), schistocytes (50%); with chronic causes, fibrinogen and platelets may actually be elevated as acute phase reactants; all factors may be variably decreased due to factor activation and consumption
Note: D-dimer may be falsely positive in HIV+ Castleman’s disease due to interference from monoclonal gammopathy (Archives 2004;128:328)
Treatment: treat underlying disease, transfuse fresh frozen plasma, platelets, cryoprecipitate if bleeding; keep fibrinogen levels above 100 mg/dL with cryoprecipitate or fresh frozen plasma; monitor PT, PTT, platelet count, fibrinogen
Case reports: 30 year old woman with DIC due to amniotic fluid embolism (Archives 2002;126:869)
Factor V inhibitor
May behave like factor VIII inhibitor in mixing studies, with increasing PTT or PT after 1-2 hours
Factor VIII inhibitor
Most common clinically significant inhibitor; develops in 10-20% of patients with severe hemophilia A after infusion of factor VIII containing products, less often with mild/moderate disease
Rarely arises in patients without hereditary hemophilia, causing acquired hemophilia A (see below)
Causes prolonged PTT; in mixing study, PTT is initially normal, then increases after 1-2 hours incubation
Associated with normal PT
In patients with hemophilia A and factor VIII inhibitor, titer of inhibitor often increases after treatment with factor VIII containing products - this does not happen with autoimmune factor VIII inhibitor
Each Bethesda unit of inhibitor decreases factor VIII concentration in assay by 50% (1 unit: 100% to 50%; 2 units: 100% to 25%; 3 units: to 12.5%, etc.)
Treatment: porcine factor VIII (if no cross reactivity with inhibitor), prothrombin complex concentrates, factor VIIa concentrates, immunosuppression for autoimmune based inhibitors
Nonhemophilic patients (autoimmune based inhibitors)
Incidence of 0.2 to 1 per million population per year
Causes bleeding
50% occur in patients with no known medical problems
Also associated with rheumatoid arthritis, SLE, post-partum; also solid tumors and hematologic malignancies
Laboratory: normal D-dimer and fibrinogen; prolonged PTT not corrected by mixing studies
Treatment: plasmapheresis (variable success), factor VIII, immunosuppression
References: Archives 2000;124:730
Factor IX inhibitor
Develops in 2-12% of patients with severe hemophilia B after transfusion of factor IX containing products, less commonly with mild/moderate disease
Rarely arises in patients without hereditary hemophilia, causing acquired hemophilia B
Causes a prolonged PTT, not corrected by mixing studies
Can quantitate titer of inhibitor
Liver dysfunction
Liver is site of production of most coagulation factors, but response of each factor to liver disease is variable due to differences in biologic half lives and acute phase reactions
PT usually prolonged first, then PTT
Factor VII: shortest biologic half life, often affected earliest with largest decrease in serum level
Factor VIII: may be normal or elevated due to acute phase reaction
Factors XI and XII: long biologic half lives, may be normal until liver disease is advanced
Lupus anticoagulants
Common
Antibodies against protein-phospholipid complexes
Causes prolonged PTT (not time dependent), increased or normal PT; may interfere with assays for factors VIII, IX, XI and XII without causing a true decrease in factor levels
May be mistaken for a factor VIII inhibitor if dilutions to abnormal factor assays are not done
Not associated with bleeding, except when accompanied by severe thrombocytopenia or factor II deficiency (rare)
Rarely causes factor II deficiency if lupus anticoagulant binds to factor II
May be associated with thrombosis
Case reports: due to phenytoin use (Archives 1987;111:719)
Proteinuria
Patients with nephrotic syndrome may have decreased factors XI and XII
Vitamin K deficiency / coumadin use
Both have same molecular mechanism for their effects
Coumadin (warfarin): therapeutic anticoagulant to reduce risk of thromboembolism; impairs regeneration of active vitamin K
Vitamin K: cofactor in carboxylation of glutamic acid residues of factors II, VII, IX and X; also protein S and C
Coumadin administration or Vitamin K deficiency cause prolonged PT; severe cases have prolonged PTT also
Vitamin K deficiency: due to fat malabsorption syndromes (vitamin K is a fat soluble vitamin), malnutrition, antibiotics (destroy bacteria producing vitamin K or interfere with vitamin K carboxylation), newborns
Treatment (coumadin overdose - INR > 5.0): fresh frozen plasma or vitamin K; PT should normalize within 12-24 hours
Treatment (vitamin K deficiency): vitamin K once, then 12-24 hours later, then measure PT (should normalize)
Hereditary bleeding disorders
Hereditary bleeding disorders-general
Acquired factor deficiencies (due to liver disease, DIC, lupus anticoagulants, heparin, warfarin or other anticoagulants) are more common than hereditary factor deficiencies, and should be ruled out first
Heterozygous patients have 30-60% of normal values of affected factors, usually with no or minor bleeding disorder
However, factor I (hypofibrinogenemia or dysfibrinogenemia), X, XI or XIII deficient heterozygotes may have bleeding symptoms
Homozygous deficient patients have <30% of normal values of affected factors
Hereditary disorders are confirmed by measuring factor levels in relatives
Combined factor deficiencies are very rare
Combined factor V and VIII: autosomal recessive, due to mutation in endoplasmic reticulum-Golgi gene ERGIC 53 on #18 that transports these factors
Combined factors II, VII, IX and X deficiency: due to mutation in gamma-glutamyl carboxylase gene, whose protein carboxylates glutamate residues in vitamin K-dependent coagulation factors
Very rare to have bleeding disorders due to deficiency in PAI-1 or antiplasmin
Symptoms: bleeding associated with surgery, trauma, dental extractions, postpartum, circumcision or umbilical stumps, GI bleeding, intracranial hemorrhage, hemarthrosis or soft tissue hematomas, easy bruising, epistaxis, menorrhagia
Algorithm for workup of hereditary bleeding disorders
Often there is a family history of bleeding disorder
PT, PTT, platelet count often normal
(a) Test for von Willebrand’s disease (most common hereditary disorder)
(b) Assays for fibrinogen, platelet aggregation, factor XIII, dysfibrinogenemia, PAI1, antiplasmin
(c) Also assays for factors VIII, IX or XI, even with normal PTT
Factor I / fibrinogen deficiency or disorders
Rare
Autosomal inheritance; most mutations are in alpha-fibrinogen chain gene, sparing beta and gamma chains
Often associated with bruising, epistaxis, menorrhagia, GI/GU bleeding, umbilical stump bleeding, miscarriage, poor wound healing; also bleeding after surgery, trauma, dental procedures, pregnancy or circumcision
May prolong PT and PTT
Need 100 mg/dL of fibrinogen for surgical hemostasis; biologic half life is 72-120 hours
Afibrinogenemia: homozygous form; causes severe quantitative deficiency of fibrinogen and increased risk of bleeding; associated with intracranial hemorrhages
Hypofibrinogenemia: heterozygous form; mild/moderate reductions in fibrinogen; little/no bleeding
Dysfibrinogenemia: qualitative fibrinogen deficiency with production of dysfunctional fibrinogen; usually heterozygous; usually either no symptoms or mild bleeding; may paradoxically be associated with thrombosis, with or without bleeding; often prolonged thrombin time and reptilase time, PT and PTT
Acquired causes: DIC, liver dysfunction - more common than hereditary deficiencies
Treatment: 1 bag of cryoprecipitate per 7 kg as needed to keep fibrinogen above 100 mg/dL; one bag raises fibrinogen by 10 mg/dL (approximately); fresh frozen plasma contains fibrinogen also, but in a much larger volume than cryoprecipitate
Factor II (prothrombin) deficiency
Rare
Autosomal inheritance
Need 10-40% for surgical hemostasis; biologic half life is 48-120 hours
Severe deficiencies associated with intracranial hemorrhage
Treatment: 10-20 ml fresh frozen plasma/kg, then 3 ml/kg every 12-24 hours as necessary; prothrombin complex concentrates may be used for serious bleeding
Factor V deficiency
Also called labile factor deficiency
Rare
Autosomal inheritance
Need 10-30% for surgical hemostasis, biologic half life is 12-36 hours
May be associated with bruising, epistaxis, menorrhagia, GI/GU bleeding, umbilical stump bleeding or bleeding after surgery, trauma, dental procedures, pregnancy or circumcision
Severe deficiencies associated with intracranial hemorrhage, although levels don’t always correlate with severity of symptoms
Treatment: 10-20 ml fresh frozen plasma/kg, then 3-6 ml/kg every 12 hours as necessary; commercial concentrates of factor V are not available
Factor VII deficiency
Also called autoprothrombin I deficiency
Rare
Autosomal inheritance
Need 10-25% for surgical hemostasis, biologic half life is 4-7 hours
May be associated with bruising, epistaxis, menorrhagia, GI/GU bleeding, umbilical stump bleeding or bleeding after surgery, trauma, dental procedures, pregnancy or circumcision
Severe deficiencies may resemble hemophilia A or B, and are associated with intracranial hemorrhage
Levels don’t always correlate with severity of symptoms
Treatment: 10-20 ml fresh frozen plasma/kg, then 3-6 ml/kg every 4 hours as necessary
Factor VIII deficiency (Hemophilia A)
Most common severe hereditary bleeding disorder
X lined recessive disorder; (gene is on X chromosome)
Need 80-100% for surgical hemostasis with major surgery or major bleeding, 30-50% postoperatively or to prevent minor bleeding
Biologic half life is 8-12 hours
Affects 1 per 5-10K males; female carriers are usually unaffected unless they have imbalanced inactivation (lyonization), Turner’s syndrome or other rare X chromosomal abnormalities; females with disease are rare (daughters of affected male and carrier female)
Clinical severity varies with factor levels: >5%: bleeding only with surgery or trauma; 1-5%; moderate bleeding; <1%: severe disease with spontaneous bleeding
30% of cases arise from new mutations, so there may be no family history
Symptoms: bleeding into muscle, soft tissue or joints (hemarthrosis), GI/GU tract; easy bruising, excessive bleeding after surgery, trauma, dental procedures or circumcision; epistaxis, poor wound healing, post-traumatic intracranial hemorrhage
Laboratory: prolonged PTT and normal PT in males with unexplained bleeding; measure factor VIII and IX levels (values of 20-30% of normal may cause prolonged PTT) and von Willebrand test panel (reduced factor VIII may be due to decrease in vWF; in female hemophilia A carriers, factor VIII/vWF ratio is 0.5 vs. 1.0 in normal females)
Notes: (a) factor VIII and vWF may be elevated during acute phase reactions, including pregnancy; must repeat tests when acute phase reaction has subsided; (b) factor VIII is labile at room temperature, and mild/moderate decreases may be due to improper processing and storage
Molecular: 40% in Caucasians are due to inversion of intron 22; also numerous other mutations; gene is large; RFLP analysis may be useful in families without the intron 22 mutation
Treatment: factor VIII concentrates (now treated to destroy other viruses, but HIV+ in early 1980’s); 1 unit/kg raises levels in vivo by 2%
major surgery/bleeding - 40-50 units factor VIII concentrate/kg every 12 hours as necessary, usually for 7-10 days,
postoperatively - 15-25 units/kg every 12 hours as necessary, usually for 7-10 days
minor bleeding - 15-20 units/kg every 12-24 hours as necessary for minor bleeding
mild/moderate bleeding - DDAVP (if patients respond to DDAVP)
References: Mol Pathol 2002;55:127 (molecular aspects)
Factor IX deficiency (hemophilia B)
Also called Christmas disease, autoprothrombin II deficiency
Severe hereditary bleeding disorder
X lined recessive disorder (gene is on X chromosome)
Need 50-80% for surgical hemostasis with major surgery or major bleeding, 40% postoperatively, 30-50% to prevent for minor bleeding
Affects 1 per 25-30K males; female carriers are unaffected; females with disease are rare
Clinical severity varies with factor levels: >5%: bleeding only with surgery or trauma; 1-5%; moderate bleeding; <1%: severe disease with spontaneous bleeding
Factor half life is 18-24 hours
Symptoms: bleeding into muscle, soft tissue or joints (hemarthrosis), GI/GU tract; easy bruising, excessive bleeding after surgery, trauma, dental procedures or circumcision; epistaxis, poor wound healing, post-traumatic intracranial hemorrhage
Laboratory: prolonged PTT and normal PT in males with unexplained bleeding; measure factor VIII and IX levels (values of 20-30% of normal may cause prolonged PTT) and von Willebrand test panel
Molecular: numerous mutations; genetic testing for female carriers or prenatal detection uses RFLP analysis
Treatment: factor IX concentrates (now treated to destroy other viruses, but HIV+ in early 1980’s); 1 unit/kg raises levels in vivo by 1%
major surgery/bleeding - 50-80 units factor IX concentrate/kg every 12-24 hours as necessary, usually for 7-10 days
postoperatively - 40 units/kg every 12-24 hours, usually for 7 days
minor bleeding - postoperatively; 30-40 units/kg q 12-24 hours as necessary
Factor X deficiency
Rare
Autosomal inheritance
Need 10-40% for surgical hemostasis, biologic half life is 24-48 hours
May be associated with bruising, epistaxis, menorrhagia, GI/GU bleeding, umbilical stump bleeding or bleeding after surgery, trauma, dental procedures, pregnancy or circumcision
Severe deficiencies may resemble hemophilia A or B, and are associated with intracranial hemorrhage
Treatment: 10-20 ml fresh frozen plasma/kg, then 3-6 ml/kg every 12 hours as necessary; may use prothrombin complex concentrates for serious bleeding
Factor XI deficiency
Common among Ashkenazi Jews
Autosomal inheritance
Need 15-50% for surgical hemostasis, biologic half life is 40-84 hours
May be associated with bruising, epistaxis, menorrhagia, GI/GU bleeding, umbilical stump bleeding or bleeding after surgery, trauma, dental procedures, pregnancy or circumcision
Levels don’t always correlate with severity of symptoms
Treatment: 10-20 ml fresh frozen plasma/kg, then 5-10 ml/kg every 24 hours as necessary
Note: factor XI concentrates may promote thromboembolic complications
Factor XII deficiency
Also called Hageman factor deficiency
Relatively common
Autosomal inheritance
Not needed in normal procoagulant pathways - deficiencies do not cause bleeding symptoms
Factor XII is activated by high molecular weight kininogen and prekallikrein
Activated factor XII converts prekallikrein to kallikrein, which activates more factor XII
Factor XIII deficiency
Rare
Autosomal inheritance
Need 5-50% for surgical hemostasis, biologic half life is 9-12 days
Although fibrin clots form, they are weak and subsequently lyse
Normal PT and PTT
Often associated with bruising, epistaxis, menorrhagia, GI/GU bleeding, umbilical stump bleeding, miscarriage, intracranial hemorrhage, poor wound healing; also bleeding after surgery, trauma, dental procedures, pregnancy or circumcision
Testing recommended if delayed bleeding, umbilical stump bleeding, or miscarriages (with normal PT and PTT)
50% of population has Val134Leu polymorphism, which may protect against deep venous thrombosis, but predispose to intracranial hemorrhage
Acquired causes of factor XIII deficiency: liver disease, DIC, Crohn’s disease, ulcerative colitis, Henoch-Schonlein purpura, leukemia, myelodysplasia, myeloproliferative disorders
Treatment: 500 ml plasma or 1 bag cryoprecipitate / 10 kg every 3 weeks
High molecular weight kininogen deficiency
Rare
Autosomal inheritance
Not needed in normal procoagulant pathways - deficiencies may cause marked prolongation of PTT, but do not cause bleeding symptoms
Prekallikrein deficiency
Rare
Autosomal inheritance
Prolonged PTT, but not associated with bleeding
Acquired cause are DIC or liver disease, rarely antibodies to prekallikrein
von Willebrand’s disease
Most common hereditary bleeding disorder, affecting 1-2% of population, no gender preference
Often mild and undiagnosed; may be masked by acute phase reactions
Due to quantitative or qualitative deficiencies of von Willebrand factor (vWF), found on #12
Symptoms are similar to a platelet function defect (epistaxis, easy bruising, bleeding, menorrhagia)
vWF is synthesized by (a) endothelial cells, stored in Weibel-Palade bodies, secreted into plasma and subendothelium and (b) megakaryocytes, present in platelets in alpha granules
vWF is large polypeptide that polymerizes to form multimers of up to 100 subunits
Plays a role in platelet plug and fibrin clot, both essential to hemostasis at site of endothelial injury
vWF mediates platelet adhesion to endothelium (and formation of platelet plug) by serving as a bridge between them - binds to GPIb glycoprotein on platelet surface and to exposed subendothelium at site of endothelial injury
vWF supports coagulation (fibrin clot) by serving as protective carrier protein for factor VIII; without vWF, factor VIII has shorter half life and its plasma levels are lower
Note: type O patients have lower levels of vWF, type AB patients have highest levels; levels increase with age and with acute phase reactions
Treatment: DDAVP (desmopressin) temporarily increases vWF and factor VIII levels 2-3x; for the patients that don’t respond, give vWF-containing factor VIII concentrates
Repeat testing is often required because vWF and factor VIII become elevated during minor illnesses, injury, stress, pregnancy, estrogen use, other acute phase reactions or in newborns
Subtypes
Type 1 (70-80%): most common, autosomal dominant, partial quantitative deficiency of vWF but normal function; causes mild/moderate bleeding disorder
Low factor VIII, vWF antigen and ristocetin cofactor; low/normal ristocetin induced platelet aggregation, normal or all sizes decreased in multimer analysis, mean ristocetin cofactor/vWF antigen ratio is 1.0; normal platelet count
Type 2 (15-20%): qualitative deficiency of vWF, variable quantitative deficiency, usually mild/moderate bleeding disorder, but may be severe
Type 2A: most common type 2 subtype; autosomal dominant; low/normal factor VIIIc and vWF; relative reduction of intermediate and high molecular weight multimers due to in vivo proteolytic degradation or defective multimer assembly and secretion; markedly reduced ristocetin cofactor, low ristocetin induced platelet aggregation; platelet vWF has similar abnormalities as plasma vWF; mean ristocetin cofactor/vWF antigen ratio is 0.3; normal platelet count
Type 2B: autosomal dominant, hemostatic defect due to intermittent thrombocytopenia and qualititatively abnormal vWF, with increased binding of vWF to GPIb (platelet vWF receptor) and faster clearing of vWF coated platelets from bloodstream; platelet count drops further during pregnancy, surgery, DDAVP therapy; low/normal factor VIIIc and vWF; reduction of high molecular weight multimers but increase in low molecular weight fragments; reduced ristocetin cofactor but increased ristocetin induced platelet aggregation; mean ristocetin cofactor/vWF antigen ratio is 0.6
Type 2C: autosomal recessive; reduction of high molecular weight multimers, increase in small multimers and qualititatively abnormal individual multimers; reduced ristocetin cofactor activity out of proportion to reductions in vWF
Type 2M: rare; autosomal dominant, decreased platelet directed function NOT due to a decrease of high molecular weight multimers, but otherwise similar to type 2A (may be due to mutation that impairs vWF and GPIb binding); low/normal factor VIII and vWF, normal multimer analysis, but very low ristocetin cofactor and low/normal ristocetin induced platelet aggregation; mean ristocetin cofactor/vWF antigen ratio is < 1.0
Type 2N: rare, autosomal recessive; markedly reduced affinity of vWF for factor VIII, causes reduction of factor VIII levels to 5% of reference range; other vWF lab tests are normal; often misdiagnosed as hemophilia A (X linked recessive), but males and females in type 2N are equally affected; assay that measures binding of factor VIII to vWF is available in specialized laboratories
Type 3: very rare; autosomal recessive, often associated with consanguinity; most severe clinical bleeding; homozygous patients have marked deficiencies of plasma vWF and factor VIIIc, no vWF in platelets and endothelial cells, no secondary transfusion response, no response to DDAVP; also undetectable ristocetin cofactor, low ristocetin induced platelet aggregation, all multimer sizes are absent
Platelet type or pseudo von Willebrand’s disease: rare disorder of mutation in GPIb (not vWF gene), causing increased binding of vWF to GPIb, with similar clinical findings as type 2B
Molecular basis of von Willebrand’s disease
Type 1: mutations throughout the gene, not well characterized
Type 2A: mutation in proteolysis site (most common type 2A mutation)
Type 2A: loss of propeptide, required for multimer formation from dimers
Type 2A: mutation in C-terminus, required for dimer formation from monomers
Type 2B: mutation in GPIb binding site, causing increased binding of vWF to GPIb
Type 2M: mutation in GPIb binding site, causing decreased binding of vWF to GPIb
Type 2N: mutation in N-terminis (factor VIII binding site), leading to decreased binding of vWF to factor VIII
Type 3: mutations throughout the gene, not well characterized
References: OMIM 193400
Therapy related coagulopathies
Coumadin / warfarin
Therapeutic anticoagulant to prevent thromboembolism by impairing regeneration of active vitamin K (warfarin is sodium salt of coumarin)
Vitamin K is a cofactor in reactions that carboxylate glutamic acid residues in factors II, VII, IX, X, protein C, protein S
Therapeutic warfarin or Vitamin K deficiency cause decreased activity for these proteins, which prolongs the PT
PTT may be normal if low warfarin levels
Takes 4-5 days for effect due to long half-life of factors II and X
Therapeutic effect is measured by INR - goal is 2-3
INR may be elevated by lupus anticoagulants or use of hirudin with warfarin
Make be supplemented with heparin (intermediate acting anticoagulant) until INR is in therapeutic range for 2 consecutive days
Treatment of bleeding/overdose: vitamin K or fresh frozen plasma
Should not be used alone for acute heparin induced thrombocytopenia, because it causes paradoxical thrombosis - must add a rapid acting anticoagulant also (hirudin, danaparoid, argatroban) until INR is therapeutic
References: J Clin Path 2004;57:1132 (reversal of warfarin)
Danaparoid (Orgaran)
Approved to prevent deep venous thromboses; also an alternative to heparin for patients with heparin induced thrombocytopenia
Composed of low molecular weight glycosaminoglycans that primarily inhibit factor Xa, factor IIa to a much lesser extent
Similar to low molecular weight heparin in having a more predictable anticoagulant effect, with less need for laboratory monitoring
Does not cause thrombocytopenia directly, but rarely reactivates it in patients with preexisting heparin induced thrombocytopenia
Monitor, if desired, with anti-factor Xa assays; draw 6 hours after subcutaneous injection; PT and PTT are unaffected
Therapeutic levels to treat DVT are 0.5-0.8 anti-factor Xa units/ml, lower for DVT prophylaxis
Long half-life, is prolonged with renal failure
No reversal agent is known
Heparin
Also called unfractionated heparin
Short acting anticoagulant
Used as initial anticoagulant therapy, to treat deep venous thrombosis, post-operatively and for other short-term indications
Decreases morbidity and mortality from acute thrombotic disease
Works by markedly enhancing activity of antithrombin, which inhibits activated factors II, IX, X, XI, XII, kallikrein and probably VII, but doesn’t cause a true decrease in factor levels
Derived from porcine intestinal mucosa or bovine lung, which contain heparin-rich mast cells
Most heparin preparations are heterogeneous, with a molecular weight between 7-25K daltons.
Anticoagulant activity is variable, since only 1/3 of heparin molecules have the pentasaccharide sequence necessary for antithrombin mediated anticoagulant activity
Complications include hemorrhage (overcoagulation) and heparin-induced thrombocytopenia
Recommended to monitor with PTT (prolonged, with therapeutic range of 1.5x mean normal range), activated clotting time (if high heparin levels present, as during cardiopulmonary bypass surgery, since no clotting occurs at these levels with PTT) or anti-factor Xa level testing (if lupus anticoagulant or factor XII deficiency, therapeutic range is 0.3 to 0.7 anti-Xa units/ml) within 12 hours; also monitor platelet count within 72 hours, with platelet monitoring to continue for 20 days; PT is usually normal
Recommended that 90% of patients should achieve therapeutic anticoagulation within 24 hours
One study disputes recommendation to reevaluate PTT therapeutic range with each new heparin lot (Archives 2001;125:1458)
Note: often the cause of prolonged PTT is heparin in sample collected through indwelling line; identify by treating with heparinase
Treatment: protamine (for emergency reversal of heparin)
Heparin - low molecular weight
Can be used instead of standard heparin for many patients, with similar efficacy and safety
Produced by breaking heparin into shorter polysaccharide chains; molecular weight is approximately 5,000 daltons
Less likely to bind to acute phase reactant proteins, platelets, platelet factor 4, macrophages and other sites, due to its shorter length
Has more predictable anticoagulant effect than standard heparin, less need for laboratory monitoring, lower incident of heparin induced thrombocytopenia, greater bioavailability
Longer half life than standard heparin (4 vs. 2 hours), which is prolonged in renal failure
Inhibits factor Xa by 2-4x more than factor IIa, so does not substantially prolong PT and PTT
Unlike heparin, does not inhibit thrombin or factor IXa
May monitor (using anti-factor Xa assays, drawn 4 hours after injection) for pregnancy, renal failure, obesity, prolonged use, children, or high risk bleeding / thrombosis patients, although usually don’t have to monitor at all, except for periodic platelet counts
Therapeutic range is 0.4 to 1.1 U/ml for twice a day dosing, higher for once a day dosing, 0.1 to 0.4 U/ml for prophylactic dosing
Effects are reversed with protamine
Hirudin
Also called lepirudin, refludan
Approved by FDA to treat thrombosis in patients with heparin induced thrombocytopenia
Recombinant protein, cloned from a leech, which directly inhibits factor IIa (thrombin)
Has more predictable anticoagulant effect than standard heparin, less need for laboratory monitoring, although close monitoring is still advised, optimally with PTT
Prolongs PT, PTT, thrombin time, ACT
Therapeutic range to treat DVT is PTT that is 1.5-2.5 x normal
Does not cause a heparin induced thrombocytopenia-type syndrome
Half life is one hour, may be prolonged if antibodies develop, dramatically prolonged in renal failure
No reversal agent
Thrombolytic therapy
Used to treat myocardial infarction, pulmonary embolism, arterial or venous thrombosis, thrombotic stroke
Thrombolytic agents include recombinant t-PA, urokinase, streptokinase
Laboratory: presence of fibrin degradation products and D-dimers, decreased fibrinogen and plasminogen, prolonged thrombin time, PT and PTT
Acquired thrombophilia / hypercoagulopathies
Acquired thrombophilia-general
Thrombophilia: any disorder associated with increased risk of venous thromboembolic disease
Common risk factors are post-operative state, trauma, pregnancy, oral contraceptives, obesity, immobility, chronic DIC, malignancy, nephrotic syndrome, paroxysmal nocturnal hemoglobinuria, systemic lupus erythematosus, polycythemia vera, essential thrombocythemia, hyperhomocysteinemia, antiphospholipid antibodies, prior thromboembolism, heparin induced thrombocytopenia, increasing age
The presence of more than one risk factor results in a further increased risk (Archives 2002;126:295)
Case reports: portal vein thrombosis associated with myeloproliferative disorder (Archives 2003;127:e385), fatal pulmonary emboli associated with hypereosinophilia (J Clin Path 2004;57:541)
Antiphospholipid antibodies
Acquired antibodies against phospholipid complexes
Occurs in 3-5% of general population; most common cause of acquired thrombophilia
Rate of thrombosis per year is 1% if no history of thrombosis, 4% in systemic lupus erythematosus (SLE) patients, 5.5% in patients with a history of thrombosis, 6% if high titer of IgG anticardiolipin
Includes lupus anticoagulant (most patients don’t have SLE) and anticardiolipin antibody
Antibodies are against phospholipids (usually transient, secondary to infection) or various plasma protein antigenic targets (beta2-glycoprotein I, protein C, protein S, annexin V, high and low molecular weight kininogens, thrombomodulin, prothrombin, factors XI and XII, complement factor H)
First described by Wassermann in 1906 (Wasserman test was complement fixation procedure using saline liver extracts from fetuses with congenital syphilis)
Associated with an increased risk of arterial or venous thrombosis, thrombocytopenia, recurrent miscarriages; causes 1/3 of strokes in patients younger than age 50 years (often due to mitral or aortic valve emboli), 15% of deep venous thromboses, 5-15% of recurrent spontaneous abortions, eclampsia, maternal DVT’s; also multi-infarct dementia, chorea, migraine, livedo reticularis in skin
Catastrophic antiphospholipid syndrome resembles TTP-HUS
Diagnosis of antiphospholipid antibody syndrome requires a positive lupus anticoagulant or anticardiolipin antibody [(a) IgG, >10 GPL units or (b) IgM, >10 MPL units and positive lupus anticoagulant test] on two separate occasions, at least 6-12 weeks apart, AND either venous or arterial thrombosis, thrombocytopenia or recurrent fetal loss
Anticardiolipin syndrome: one major clinical finding (venous thrombosis, arterial thrombosis, recurrent fetal loss, and thrombocytopenia) plus positive laboratory test result indicating anticardiolipin antibodies or positive lupus anticoagulant (prolonged dilute Russell viper venom test, prolonged PTT); must also retest patient 8-10 weeks after initial positive laboratory tests to rule out transient antiphospholipid antibodies due to infection
References: Archives 2002;126:1424
Heparin induced thrombocytopenia
Common complication of heparin therapy, may cause life threatening venous or arterial thrombosis
Prevent by monitoring platelet count for at least 20 days after initiation of heparin therapy
Treatment: permanently discontinue heparin, avoid platelet transfusions; recommended to not use low molecular weight heparin (may cross react) or coumadin (may cause venous limb gangrene); instead use danaparoid, hirudin or argatroban
Hereditary thrombophilia / hypercoagulopathies
Hereditary thrombophilia-general
Thrombotic disorders due in part to deficiencies in natural anticoagulant or fibrinolytic systems
Acquired risk factors, such as oral contraceptive use, may synergistically increase the risk for thrombosis
Disorders often occur at a young age; usually affects venous system
Workup includes documenting all acquired risk factors for thrombosis
Activated protein C resistance
Most common hereditary predisposition to venous thrombosis (20% of first episodes of thrombosis, 50% of familial thrombosis)
Normally, activated protein C degrades activated factors V and VIII by cleaving specific arginine residues
Almost all patients with activated protein C resistance have Factor V Leiden mutation that causes resistance to degradation by activated protein C
Does not appear to reduce life expectancy
Factor V Leiden
95% with activated protein C resistance have point mutation at an arginine cleavage site (Arg506Gln, 1691 G to A) called R506Q or Factor V Leiden
Mutation causes delayed inactivation by activated protein C, prolonging its life span and procoagulant activity
3-5% frequency in heterozygous form in general white population; rare in African blacks and Asians
Heterozygotes have 2.6x increased risk for dural sinus thrombosis, 3-10x increased risk for venous thrombosis
Homozygotes have 80x increased risk for venous thrombosis; risk occurs later in life
Homozygosity or heterozygosity without symptoms may not require treatment
Presence of second risk factor (genetic or acquired) is often necessary to produce thrombosis; acquired risk factors are malignancy, trauma, surgery, oral contraceptive use, estrogen replacement therapy, antiphospholipid antibody, heterozygosity for prothrombin G20210A, elevated serum homocysteine
Other low frequency factor V mutations (besides Factor V Leiden) are factor V Cambridge (Arg306Thr) and factor V Hong Kong (Arg306Gly); also HR2 haplotype with mutation 4070A to G (His199Arg) in exon 13 of factor V gene, which is associated with other polymorphisms; all have unclear association with venous thrombosis
Testing recommended if venous thromboemboli occur with these features: recurrent, before age 50 years, unprovoked at any age, at unusual anatomic sites (cerebral, mesenteric, portal or hepatic veins), in patient with first degree relative with venous thromboemboli before age 50 years; related to pregnancy or estrogen use or unexplained pregnancy loss in second or third trimesters; may be recommended in family members (with family history), female family members who are pregnant or considering oral contraceptives
Testing not recommended: general population screen, routine test during pregnancy, routine test before or during oral contraceptive use or hormone replacement therapy; as newborn initial test, as initial test in patients with arterial thrombotic events
Treatment: treat venous thromboemboli similarly regardless of the presence of factor V Leiden
Case reports: 51 year old woman with heterozygous factor V Leiden and dural sinus thrombosis (Archives 2003;127:1359)
References: Archives 2002;126:577
Antithrombin deficiency
Hereditary deficiencies occur in 0.07 to 0.17% of general population; many mutations exist (qualitative or quantitative); usually autosomal dominant
Present in 1-9% of patients with venous thrombosis
Higher risk for venous and arterial thrombosis than protein C or S deficiency or activated protein C resistance; often occurs with other genetic or acquired risk factors
Heterozygotes have levels 35-75% of normal; first thrombotic event occurs between ages 10-50 years; overall 50% have thrombosis
Homozygosity is very rare, usually incompatible with life due to neonatal thrombosis, except for those with a heparin-binding mutation subtype, who have severe thrombosis but may survive
Type I mutations: quantitative deficiency with 50% of normal levels; due to any of 80 point mutations
Type II mutations: dysfunctional protein; often asymptomatic
IIa: mutations affect reactive site of target protease
IIb: mutations affect heparin binding site
IIc: recurrent missense mutati9ons;
Treatment: heparin (unfractionated or low molecular weight), followed by warfarin; may need increased doses of heparin or antithrombin concentrates if resistant to heparin; should monitor antithrombin levels (should be 80-120%)
Acquired causes: liver disease, malnutrition, inflammatory bowel disease, extensive burns, recent or active thrombosis (including DIC), heparin therapy, acute hemolytic transfusion reaction, malignancy, L-asparaginase therapy, acute thrombotic episodes, heparin therapy, nephrotic syndrome
References: Archives 2002;126:1326, more information #1, #2
Dysfibrinogenemia
Disorders of fibrinogen structure; have variable effects on function (25% associated with bleeding, 20% associated with thrombosis, 55% have no symptoms or prolonged thrombin time)
Bleeding due to defective fibrin clot formation (impaired release of fibrinopeptides A or B and impaired fibrin monomer polymerization)
Thrombosis due to (a) defective thrombin binding to fibrin, causing increased thrombin in circulation and more thrombosis; (b) defective binding of tPA or plasminogen to fibrin or fibrin resistance to plasmin; includes Dusart (Paris V) and Chappel Hill III dysfibrinogens that are resistant to degradation by plasmin
Congenital (hereditary) dysfibrinogenemia is a rare cause of hypercoagulability (350 reported cases, 0.8% of patients with venous thrombosis); usually due to single amino acid substitutions in fibrinogen Aalpha, Bbeta or gamma genes; recommended to NOT test for dysfibrinogenemia in patients with thrombosis since so rare
Autosomal dominant inheritance, but higher incidence in women due to pregnancy related thrombosis, particularly post-partum and in venous lower extremities, at mean age 27 years; also associated with spontaneous abortions
Laboratory testing: primary screening test is thrombin time (prolonged except for fibrinogens Oslo I and Valhalla - shortened); prolongation may also be due to heparin, heparin-like inhibitors, fibrin degradation products, hypofibrinogenemia, excess fibrinogen, paraproteins, excess protamine, anti-fibrinogen antibodies, anti-bovine thrombin antibodies, systemic amyloidosis, acquired dysfibrinogenemia; reptilase time is less sensitive than thrombin time, but not affected by heparin
Confirmatory test (if thrombin time or reptilase time is prolonged): fibrinogen activity-antigen ratio below reference range; activity measured by Class method (rate of clot formation after adding high concentration of thrombin to citrated plasma; use standard curve relating clotting time to plasma of known fibrinogen activity); antigen concentration determined by ELISA, radial immunodiffusion, precipitation or thrombin clotting methods; perform both tests on same sample in same laboratory and using method-specific reference ranges
Diagnosis: similar laboratory test abnormalities in family members; if necessary, demonstrate abnormal structure or function of fibrinogen
Diagnosis of acquired dysfibrinogenemia: abnormal liver function tests, no dysfibrinogenemia in family members
References: Archives 2002;126:1387, Archives 2002;126:499, http://www.geht.org/databaseang/fibrinogen (online database of fibrinogen mutations)
Elevated coagulation factor levels in plasma
May predispose to thrombosis
Factor I (fibrinogen): high levels associated with increased risk for myocardial infarction, arterial thrombosis
Not recommended to measure to assess thrombotic risk, since assay has not been standardized, independent effect appears to be modest, insufficient clinical data to demonstrate that lowering fibrinogen will present ischemic heart disease
Factor II (prothrombin): high levels associated with increased risk of venous thrombosis; also G20210A mutation (see below)
Factor V: high levels associated with increased risk of arterial thrombosis
Not recommended to measure to assess thrombotic risk, since not associated with venous thrombosis, only one study relates factor V activity and ischemic heart disease, methodology is inadequate to assess individual levels, there are no studies showing that reduction of factor V activity will reduce risk for ischemic heart disease or stroke
Factor VII: high levels or certain genetic polymorphisms are associated with increased risk for myocardial infarction, but not an independent risk factor; levels are associated with triglyceride and cholesterol levels
Factor VIII: high levels associated with increased risk of venous thrombosis and arterial thrombosis; however normal range varies about 3 fold, levels vary with ABO blood type (15% lower with type 0) and is acute phase reactant; if no acute stress reaction, no aerobic exercise in past 24 hours, no estrogenic effects, then baseline value >150% is significant risk factor
Not recommended to assess individual risk because no established standard for elevated levels, tremendous interlaboratory variation, causal relationship is not yet established
Factor IX: high levels associated with increased risk of venous thrombosis; not recommended to assess individual venous thrombosis risk due to limited amount of clinical data and limited availability of factor IX ELISA
Factor XI: high levels (>121%) associated with increased risk of venous thrombosis; not recommended to assess individual venous thrombosis risk because (1) association was found in Netherlands and may not apply to other populations; (2) factor XI assays not generally available; (3) one step clotting assay and PTT based assays may be too variable; (4) may be affected by other variables
Factor XIII: polymorphism Val34Leu may protect against venous thrombosis (Archives 2002;126:1391)
von Willebrand factor: high levels associated with increased risk of arterial thrombosis; not recommended to assess individual thrombotic risk because it is not an independent risk factor, and no studies show that reduction of vWF levels reduces risk of ischemic heart disease, stroke or peripheral arterial disease
References: Archives 2002;126:1405
Heparin cofactor II deficiency
Very rare hypercoagulable condition, either hereditary (autosomal dominant, 15 families documented through 2002) or acquired (liver disease)
Associated with thrombosis, but not a strong risk factor by itself
Testing patients with thromboembolic disease for heparin cofactor II deficiency is not recommended (Archives 2002;126:1394)
Hyperhomocysteinemia
Homocysteine is an amino acid, derived from methionine, may be converted to cysteine
Its metabolic pathways require vitamins B12, B6 and folate; elevated levels may be hereditary (due to mutations in these pathways) or acquired (due to deficiencies of vitamins B12, B6 or folate, renal failure, carcinoma, hypothyroidism or medications)
Elevations in homocysteine are associated with increased risk of arterial and venous thrombosis and atherosclerosis, based on retrospective case control studies; prospective studies show a weak positive association with arterial thrombosis, and no definite association for venous thrombosis
Homozygosity or heterozygosity for the C677T mutation in MTHFR gene (methylene tetrahydrofolate reductase), which is involved in homocysteine metabolic pathway, does not appear to be a risk factor for thrombosis; may be significant in folate-deficient patients
Consider testing patients with documented coronary artery disease, cerebrovascular disease or peripheral vascular disease for homocysteine; high levels can be treated with vitamins B6, B12, or folic acid, although they may not reduce the risk of future cardiovascular events
References: Archives 2002;126:1367
Protein C deficiency
Hereditary deficiencies occur in 0.14 - 0.5% of general population; >160 mutations exist, either type I (76%, usually quantitative) or type II (dysfunctional protein, normal protein levels)
Causes 1-11% of cases of venous thrombosis; these patients also at risk for coumadin-induced skin necrosis if treated with coumadin but no heparin until coumadin levels are therapeutic
Heterozygotes have levels 35-65% of normal; first thrombotic event occurs between ages 10-50 years; only 30% have thromboembolism, increasing to 75% if coexisting factor V Leiden
Homozygotes (1 per 500-750K births) with severely decreased levels present as newborns with DIC and purpura fulminans neonatorum, leading to death unless anticoagulation and replacement therapy with fresh frozen plasma is started
Must exclude acquired causes of protein C deficiency
Acquired causes of low protein C levels: clot formation, surgery, liver disease, coumadin (should be discontinued at least 10 days prior to testing) or Vitamin K antagonist therapy, DIC, vitamin K deficiency, L-asparaginase therapy
Acquired causes of increased protein C (may mask protein C deficiency): ischemic heart disease, pregnancy, postmenopausal women, hormone replacement therapy, oral contraceptives
References: Archives 2002;126:1337
Protein S deficiency
Hereditary deficiencies occur in 0.7% of general population; many mutations exist (qualitative or quantitative); much lower prevalence of thrombophilia with clustering in families; variable penetrance may be due to coexisting risk factors, such as factor V Leiden
Causes 1-9% of cases of venous thrombosis; these patients also at risk for coumadin-induced skin necrosis if started on coumadin without the addition of heparin until coumadin levels are therapeutic
Heterozygotes have levels 35-65% of normal; first thrombotic event occurs between ages 10-50 years; 50% risk by age 45
Homozygotes with severely decreased levels present as newborns with DIC and purpura fulminans, leading to death unless anticoagulation and replacement therapy with fresh frozen plasma is started
Type I (2/3): low free and total protein S antigen, with decreased APC cofactor activity
Type II (rare): normal free and total protein S antigen, and decreased APC cofactor activity
Type III (1/3): normal to low total protein S, low free protein S antigen, and an elevated fraction of protein S bound to C4B protein
Testing recommended: individual with family history who requests testing, to confirm abnormal protein S result; must interpret with caution
Testing not recommended: during pregnancy or postpartum, during inflammatory, thrombotic or surgical event; within 30 days of taking warfarin; must delay longer periods for vitamin K antagonists (Phenprocoumon)
References: Archives 2002;126:1349
Prothrombin gene mutation (G20210A)
Mutation in G to A transition at nucleotide 20210 in 3’ untranslated portion of prothrombin gene, which introduces a new Hind III site
Associated with (may not directly cause) increased prothrombin levels, 2-5x increased risk of venous thrombosis
Risk is multiplicative if taking oral contraceptives and have factor V Leiden gene
Heterozygous form occurs in 1-2% of normal individuals, 6-20% of patients with venous thrombosis
Testing via PCR based assay
Testing recommended: patients with recurrent venous thromboembolic, first episode before age 50, first unprovoked venous thromboemboli at any age, thromboses at unusual anatomic sites (cerebral, mesenteric, portal or hepatic veins), venous thromboemboli in patient with first degree relative with venous thromboemboli before age 50 years; venous thromboemboli related to pregnancy or estrogen use, or unexplained pregnancy loss in second or third trimesters; young individuals with myocardial infarction and no other risk factors; also test factor V Leiden and other mutations (combination most clearly impacts clinical decision making)
Testing not recommended: as general population screen, routine test during pregnancy, routine test before or during oral contraceptive use or hormone replacement therapy; as newborn initial test, as initial test in patients with arterial thrombotic events
Treatment: patients with thromboemboli and this mutation should receive similar treatment as other patients with venous thromboemboli
References: Archives 2002;126:1319
Sickle cell disease
Associated with increases in thrombin generation, fibrinolytic activation, platelet activation, increased antiphospholipid antibodies, decreased levels of circulating anticoagulants and contact factors, increased circulating levels of tissue factor and endothelial cells expressing a tissue factor phenotype
Have hypercoagulable state based on thermoelastographic profiles (Archives 2005;129:760)
Coagulation laboratory tests
Coagulation laboratory tests-general
Performed in almost all hospitals in US
Necessary for diagnosis, treatment and management of bleeding and hypercoagulation disorders, to screen for coagulation disorders and to monitor anticoagulant therapy
CAP requires laboratories to notify medical staff immediately if a critical value is obtained; CLIA requires laboratory to immediately alert
individual or entity that requested the test, or if applicable, the individual responsible for using the test results
Specimens: (a) use tubes with 3.2% but not 3.8% citrate (prolongs PT and PTT if sample not completely filled); (b) do not draw specimens from indwelling catheters (which contain anticoagulants); (c) if multiple tubes are drawn, draw coagulation tube after the red top and before the EDTA, heparin or oxalate/fluoride tubes; (d) try to fill the sample tube completely; (e) notify laboratory if patient is on anticoagulants and specify which ones; (e) don’t delay transport of tubes to laboratory; if delay cannot be avoided, separate plasma or serum from cells as soon as possible; store plasma (or serum) on ice for up to 4 hours, or store frozen
References: Archives 2005;129:47
Quality assurance
Important to prevent laboratory errors
CLIA regulations require patient and control specimens be tested in duplicate only for manual coagulation tests, but not for automated tests
CLIA regulations require calibration and calibration verification procures to substantiate continued accuracy throughout the laboratory’s reportable range of test results
Abnormal PT and PTT - causes
PT normal, PTT prolonged: deficiency of intrinsic pathway factors VIII, IX, XI, XII; less commonly prekallikrein or high molecular weight kininogen; also delay in transporting specimen to lab (affects factors V and VIII)
PT prolonged, PTT normal: deficiency of extrinsic pathway factor VII; occasionally due to deficiency of common pathway factors fibrinogen, prothrombin, factors V or X
PT and PTT prolonged: deficiency of common pathway factors fibrinogen, prothrombin, factors V or X, or multiple factor deficiencies
Activated clotting time
Whole blood clotting assay, usually performed at bedside, to monitor high-dose heparin anticoagulation (cardiopulmonary bypass surgery) or to immediately measure heparin (ECMO, hemodialysis, cardiac catheterization)
Note: test is necessary for high-dose heparin monitoring because PTT is unclottable
Whole blood is collected into tube with celite (diatomaceous earth), kaolin, glass particles or other activator of intrinsic pathway; tube may need to be shaken to disperse the activator; tube is monitored by instrument that records time until clot is formed
Do not collect blood from line containing heparin
Target reference range depends on the method: usually 70-180 seconds, 400+ seconds for cardiopulmonary bypass operations
Does not correlate well with PTT
Affected by platelet count and function, lupus anticoagulant, factor deficiencies, patient and ambient temperature, hemodilution, aprotinin (reversible platelet inhibitor that prolongs celite-based tests)
Activated protein C resistance assay
See Factor V Leiden assay (below)
Anticardiolipin antibodies
One of the two main types of antiphospholipid antibodies (other is lupus anticoagulant)
Indications: patients with venous thromboembolism (particularly if no family history or associated with autoimmune disease); unexplained stroke (young person or autoimmune disease), cerebral venous thrombosis, recurrent or late pregnancy loss; may be considered for arterial thrombosis (particularly in young patient or no documented atherosclerosis)
Specimen: serum (red top)
Methodology: ELISA test to recognize proteins (not actually cardiolipin) bound to a microtiter plate; tests for anti-prothrombin and anti-beta2-GPI antibodies have had limited prospective studies
IgG recommended to evaluated hypercoagulability (risk with IgM or IgA antibodies is uncertain); titers >40 GIU are most closely associated with hypercoagulability
200-400x more sensitive than VDRL, but patient with syphilitic infection may have positive anticardiolipin antibody test results
High sensitivity plates have greater antigenic density on microtiter plate, may be irradiated for greater antigenic density and to facilitate bivalent bonding of plasma antibodies
62% positivity in patients with SLE or other autoimmune results
To demonstrate persistence, positive test must be confirmed by repeat testing after 6 weeks
References: Archives 2002;126:1424
Antiplasmin assay
Also called anti-alpha2-antiplasmin, plasmin inhibitor
An uncommon assay usually sent to reference laboratories
Indications: familial bleeding disorder, after ruling out more common bleeding disorders such as von Willebrand disease
Specimen: plasma in citrate tube, without epsilon-aminocaproic acid, aprotinin, heparin or other fibrinolysis inhibitors
Reference range: approximately 48-80 mg/dL, lower during first 5 days of life
Functional assays: add specific amount of excess plasmin to patient’s plasma, measure plasmin that is unbound to antiplasmin in patient’s serum by detecting color change spectrophotometrically; amount of unbound plasmin detected is inversely proportional to patient’s antiplasmin level
Antigenic (immunologic) assay: patient’s plasma in placed in the cylindrical well of an agarose gel containing antiplasmin antibody, which defuses into the well and forms an antigen-antibody complex and precipitin ring; the size of the ring is proportional to the patient’s antiplasmin
Acquired causes of decreased antiplasmin: liver disease, thrombolytic therapy, DIC
Antithrombin assay
Assays detect antigenic (type I, reduced normal protein, quantitative) or functional (type II, normal amount of defective protein, qualitative) deficiencies of antithrombin (formerly called antithrombin III)
Perform functional assay first - if decreased, perform antigenic assay on fresh specimen; family studies may be helpful
Functional assays: are chromogenic, use predominantly amidolytic methods (i.e. through cleavage of an amide bond), employing a synthetic peptide that mimics the natural target of the enzyme; patient plasma is incubated with excess thrombin and heparin; antithrombin neutralizes thrombin, and remaining thrombin is then quantitated with a chromogenic substance; the amount detected is inversely proportional to the patient’s antithrombin
Functional assay limitations - false levels may be produced if high levels of heparin cofactor II are present; this is eliminated by assays that use inhibition of factor Xa rather than thrombin; newer assays have protease inhibitors to minimize nonspecific substrate cleavage and bovine thrombin; hirudin or argatroban anticoagulation may interfere with thrombin based assays
Antigenic assays: quantification is usually via radial immunodiffusion techniques, although they have coefficients of variation of 40-50%; amidolytic assays have CV of only 9-14%; also used are latex particles coated with antithrombin antibodies; light absorbance is related to the amount of antithrombin in the specimen
Antigenic assay limitations - does not detect functional deficiencies by itself
If initial antithrombin result is low, should do confirmatory test on repeat specimen; also family studies (first degree relatives); must also exclude acquired causes
Specimen: plasma in sodium citrate tube
Levels are lower in newborns; rise to adult levels (112-140 mg/liter) by age 6-12 months
Mildly decreased values (70-80%) are unlikely to be associated with thrombosis
Indications: evaluation of individuals with thrombophilia (strong family history or young patient); also analyze for factor V Leiden and prothrombin G20210A; preferable to not test during the acute phase of a thrombotic event (normal antithrombin value makes antithrombin deficiency unlikely, although cannot interpret mildly abnormal values)
Acquired causes of low antithrombin levels: clot formation, surgical procedures, liver disease, nephrotic syndrome, DIC, heparin (full dose therapy decreases levels by up to 30%), L-asparaginase therapy, possibly pregnancy or oral contraceptives
Acquired causes of high antithrombin levels: coumadin therapy
References: Archives 2002;126:1326
Bleeding time
A relatively nonspecific and nonsensitive test of platelet function, whose use is declining
Test is affected by use of aspirin or other NSAIDs; patients should abstain from their use for 1 week prior to testing
Test is also affected by how incision is made (difficult to standardize)
Procedure: place blood pressure cuff on arm at 40 mm Hg; then trained technician makes a small incision on patient’s arm, blots the blood gently every 30 seconds with filter paper without touching the wound to see if bleeding has stopped and records the time; then apply bandage
Duke bleeding time: uses earlobe or fingertip pierced with lancet
Ivy bleeding time: blood pressure cuff at 40 mm Hg on arm, and forearm cut by lancet
Mielke (template) bleeding time: template placed on skin with spring loaded blade that cuts through template, to standardize the size and depth of cut
Reference range: 1.5 to 9.5 minutes (less in newborns)
Prolonged values: platelet count less than 100K, low hemoglobin, use of aspirin or other platelet inhibitors; also von Willebrand’s and other hereditary platelet disorders, uremia
Clot retraction
Obsolete test
Uses whole blood in red top tube; examine clot at 1, 2, 4 and 24 hours for clot retraction; after clot forms, remaining 40-60% consists of serum and red blood cell “fall-out” from clot
Reduced clot formation: Glanzmann thrombasthenia (reduced glycoprotein IIb/IIIa causes reduced platelet aggregation and clot retraction); DIC, hypofibrinogenemia, dysfibrinogenemia (small clot with increased red blood cell “fall-out”)
Cryofibrinogen assay
Either asymptomatic or causes cutaneous symptoms at cold-exposed areas
Cryofibrinogen consists of fibrinogen and other substances that precipitate at cold temperatures (cryoglobulins are immunoglobulins that precipitate at cold temperatures)
Either primary, or associated with malignancy, infection, inflammatory conditions, diabetes, pregnancy, oral contraceptives; may exhibit leukocytoclastic vasculitis in skin biopsies
Specimen: two sodium citrate or EDTA tubes plus one red top tube for cryoglobulin; place immediately in warm water and transport to laboratory within 2 hours; don’t use heparin-containing specimens (heparin precipitates fibrinogen in this assay)
Indication: for patients with unexplained cutaneous ulcers or ischemia on cold-exposed areas
Procedure: centrifuge at 37C, refrigerate plasma, centrifuge at 4C; each mm of visible precipitate represents 1% of cryofibrinogen; cyrocrit is %volume of precipitate compared to total plasma
Also perform cryoglobulin test to ensure that plasma precipitate is not a cryoglobulin
D-dimer / dimerized plasmin fragment D
Marker of ongoing procoagulant activity
Fibrin degradation products (fibrin split products) that are formed only by plasmin degradation of fibrin, not by plasmin degradation of intact fibrinogen; thus indicating that fibrin has been formed
Normal plasma level is probably due to physiologic clotting activity
Specimen: usually plasma with citrate anticoagulant
Values < 0.5 mg/L with ELISA assays have good negative predictive value for thromboembolic disorders; other values are not predictive (Archives 2004;128:519)
Suggested guidelines for D-dimer testing to rule out pulmonary emboli in patients with low clinical suspicion (if moderate or high clinical suspicion, should do imaging studies): age < 70 years, and no unexplained hypoxemia, unilateral leg swelling, recent surgery, hemoptysis, pregnancy or prolonged duration of symptoms (Acad Emerg Med 2005;12:20)
Elevated levels are sensitive but not specific for DIC
Elevated levels after completion of oral anticoagulation are associated with venous thromboemboli
Latex agglutination method: mix patient plasma with latex particles coated with monoclonal anti-D-dimers or fibrin degradation product antibodies; detect agglutination with coagulation analyzer and semiquantitate with dilutions
ELISA method: also available
False positives: HIV+ Castleman’s disease due to interference from monoclonal gammopathy (Archives 2004;128:328), high rheumatoid factor, liver disease, post-operatively, cancer patients, pregnancy
References: CAP Today; May 2005 (cutoff values for venous thromboemboli), CAP Today; April 2005 (new tests and uses)
Factor assays
PT (factors II, V, VII, X) or PTT (factors V, VIII, IX, XI, XII) based reactions, performed by mixing patient plasma with plasma that is deficient in the factor being measured
PT or PTT is compared to standard curve, to determine amount of factor present in patient’s plasma
Used to determine the etiology of a prolonged PT or PTT
Factor levels are expressed as % of normal plasma concentration, or units per mL of normal plasma; reference range is usually 60-140%
Perform at multiple dilutions to rule out an inhibitor - at higher dilutions, inhibitor interference should decrease due to dilution of the inhibitor
Can also use enzyme immunoassays to quantitate
Levels at birth of factors other than factor VIII are 10-100% of adult levels, but reach adult levels at 6 months
Factor I (fibrinogen) assay
Clauss method: a functional test that is essentially a dilute thrombin time; add diluted patient plasma to high concentration of thrombin, which converts fibrinogen to fibrin; clotting time is inversely proportionate to fibrinogen in sample; values are falsely decreased by heparin > 0.6 units/mL or fibrin degradation products
Ellis method: thrombin (less than Clauss method) is added to undiluted patient plasma and spectrophotometer records change in turbidity
PT based method: thromboplastin (tissue factor with phospholipids) is added to undiluted patient plasma and light scatter or turbidity is measured; the measured optical change (before and after fibrin clot formation) is proportional to amount of fibrinogen
Immunologic methods: use anti-fibrinogen antibodies; usually a send-out test
Values decrease with liver disease (usually late), DIC, thrombolytic therapy, fibrinolysis
Values falsely decreased by bivalirudin, lepirudin, argatroban, and fondaparinux (Archives 2004;128:1142)
Values increased in acute phase reactions and during pregnancy
Reference range: 150-400 mg/dL
Factor V Leiden assay
Also called activated protein C resistance (APC)
Uses plasma (in citrate tube) for screening assay and whole blood for DNA based confirmation assay
Procedure:
(1) dilute patient plasma 1:5 with factor V deficient plasma (dilutes the effect of other factor deficiencies or elevations) and add polybrene (neutralizes unfractionated heparin or low molecular weight heparin)
(2) if lupus anticoagulant is present, must perform DNA based test for Factor V Leiden (or perhaps 1:40 dilution of plasma or add phospholipids to neutralize lupus anticoagulant)
(3) calculate ratio of PTT with versus without exogenous activated protein C; normal is 2.0 or more, factor V Leiden usually < 2.0 (sensitivity and specificity approach 100%, because these patient’s activated factor V resists activated protein C degradation)
Note: use 1:11 dilution for newborns age 0-6 months
Other assays: (a) prothrombin-based factor V assay with factor V deficient plasma (no interference from lupus anticoagulant)
(b) modified Russell viper venom time test (high phospholipids neutralizes lupus anticoagulant)
(c) factor Xa-based assay with factor V deficient plasma
(d) PCR (using whole blood, not plasma); absence of MnlI cleavage at mutation site, guanine to adenine at #1691, or arginine to glutamine at amino acid #506 indicates factor V Leiden mutation
References: Archives 1998;122:430 (advantages of step 1 above)
Factor VII assay
Usually a one stage, prothrombin based assay
Results distorted by cold activation of factor VII, by variable sensitivity of thromboplastins to activity of factor VII vs. VIIa
Can also use enzyme immunoassay
Factor VIII assay
Assay is PTT based clotting assay that measures factor VIII activity
Use severely deficient factor VIII plasma as substrate for one stage clotting assay, although there is tremendous interlaboratory variability
Can also use chromogenic assay, ELISA
Low levels: hemophilia, vWF disease with decreased vWF antigen levels, delay in transporting specimen to lab
Note: levels are not decreased at birth or throughout childhood; levels may increase during pregnancy
Factor VIII inhibitor assay
Methodology: prepare serial dilutions of patient plasma in citrated saline from 1:1 to 1:160 (or high); mix each dilution with an equal volume of normal plasma containing a normal amount of coagulation factors, incubate for 2 hours, then perform factor VIII assay; titer of inhibitor is dilution that inhibits 50% of factor VIII in assay
Factor IX assay
A linear, dose-dependent, false decrease is caused by bivalirudin, lepirudin, argatroban, and fondaparinux (Archives 2004;128:1142)
Factor Xa assay
Used to monitor heparin, particularly if PTT has baseline prolongation due to lupus anticoagulant or factor XII deficiency
Note: can cautiously use PTT to monitor heparin, even if lupus anticoagulant present, if factor Xa assay demonstrates that it is not affected by the lupus anticoagulant
Also used to monitor low molecular weight heparin and danaparoid, which don’t prolong PTT; however, these products have more predictable results, and don’t need to be monitored except if renal failure, pregnancy (increased dosage needed in third trimester), newborns (increased dosage needed), over- or underweight patients, prolonged use or high risk for bleeding/thrombosis
Standard therapeutic range is 0.3 to 0.7 anti-Xa units/mL
Measures ability of heparin in patient’s plasma to inhibit known amount of factor Xa
Sampling: draw specimen 4 hours after subcutaneous injection of low molecular weight heparin or 6 hours after subcutaneous injection of damaparoid to avoid falsely low values; must deliver to laboratory immediately (or separate plasma from cells within 1 hour), because platelets release platelet factor 4, which neutralizes heparin; delays may cause falsely low values
Therapeutic range for treatment of existing deep venous thrombosis: heparin – 0.3 to 0.7 units/mL; low molecular weight heparin – either 0.4 to 1.1 units/mL for twice a day dosing or 1 to 2 units/mL for once daily dosing; danaparoid – 0.5 to 0.8 units/mL
Chromogenic factor X assays: used to monitor warfarin in the presence of a lupus anticoagulant, hirudin or argatroban (which prolong the PT and increase the INR), because warfarin decreases factor X (also factors II, VII, IX), and the chromogenic assay has no interference from lupus anticoagulant, hirudin or argatroban; patient plasma is added to a known amount of excess factor Xa with excess antithrombin; anticoagulant binds to antithrombin and inhibits factor Xa; residual factor Xa is inversely proportional to anticoagulant in plasma, cleaves a chromogenic substrate, and colored compound is detected by spectrophotometer; results reported in antifactor Xa units/mL
Interpretation: low levels of factor Xa are due to (a) not collecting specimen at right time or delayed transportation to lab (see Sampling above), (b) higher therapeutic dose needed; high levels of factor Xa are due to (a) renal failure, (b) heparin contamination (specimen drawn from indwelling line containing heparin), (c) lower therapeutic dose needed
Factor XI assay
Determine by one step clotting activity assay, comparing dilutions of patient plasma to clotting times of dilutions of pooled plasma from normals
Use plasma from individuals with <1% activity of immunodepleted normal plasma
Can also use chromogenic substrate after add inhibitors to factor XIIa and kallikrein
Levels may decrease during pregnancy
Factor XIII assay
Indications: patients with familial bleeding disorder but normal PT and PTT and normal von Willebrand panel
Screening assay: evaluates clot stability in 5M urea; add calcium to patient plasma to make it clot, incubate for 30 minutes at 37C, then place clot in 5M urea for 24 hours at room temperature; normal patients have stable cots, but patients with factor XIII deficiency of 1-2% of normal have clots that dissolve in urea; screening assay does not detect heterozygotes
Quantitative assay: reference range is 70-140% of normal; detects values of 50% of normal (heterozygous deficiencies); expensive and not readily available, factor XIII is activated by thrombin, attaches glycine ethyl ester to a peptide substrate, releasing ammonia detected by photometer; high serum ammonia levels falsely decrease the result
Note: newborns may have lower levels than adults
Heparin induced thrombocytopenia
Determine if thrombosis or thrombocytopenia in a patient exposed to heparin is due to anti-heparin antibody (actually antibody to heparin bound to platelet factor 4 on platelet surface)
Heparin exposure may be minimal (heparin-coated catheter)
Note: 8% of heparinized patients have antibody without symptoms, 1-5% have thrombocytopenia, 1/3 of these develop arterial or venous thrombosis, 20-30% of these die and 20-30% become disabled
Affected patients usually have reduction in platelet count within 4-20 days after heparin exposure for the first time, 1-3 days after reexposure to heparin, platelet count typically decreases 50% or more to under 100K; starts to rise 2-3 days after ceasing heparin, with normal levels at 4-10 days after heparin cessation
Antibody binds to heparin-platelet factor 4 complex, antibody then binds to platelet Fc receptor, which activates the platelet, causing thrombocytopenia and thrombosis
Test should be performed in acute setting, before antibody disappears
Methodology: either ELISA (90% sensitive; heparin complexed to platelet factor 4 as antigen), platelet aggregation (add patient plasma/serum to donor platelets and heparin, check for platelet aggregation) or serotonin release assays (add patient plasma/serum and heparin to donor platelets with radiolabeled serotonin, check for release of serotonin from platelets activated by the antibody)
Heparinase
To detect heparin contamination of specimens, which may cause a prolonged PTT
Also used to remove heparin from specimens so coagulation tests can be performed without interference
Heparinase degrades unfractionated and low molecular weight heparin at multiple sites, including the antithrombin binding site (pentasaccharide sequence), producing fragments up to 1000 daltons, which lack anticoagulant activity
Methodology: measure PTT before and after heparinase (add 1 mL of patient plasma to one vial of heparinase, keep at room temperature for 15 minutes); alternative is to add heparin-binding cellulose to specimens, which binds to heparin, then centrifuge and use supernatant plasma (free of heparin)
Notes: normal thrombin time rules out heparin prolonging the PTT; may have coagulation abnormality in addition to heparin contamination; marked reduction of PTT, but with elevated value, may indicate residual heparin
High molecular weight kininogen assay
Interference occurs in these assays if patient on heparin, hirudin or argatroban, possibly danaparoid
Lower levels in newborns, increase to adult levels by age 6 months
Indications: to determine cause of prolonged PTT, if PTT normalizes in mixing study, factors VIII, IX, XI and XII are normal, PT and fibrinogen are normal, lupus anticoagulant is negative
Methodology: mix patient plasma with high molecular weight kininogen deficient plasma, perform PTT, and compare to standard curve of high molecular weight kininogen vs. PTT
Homocysteine assay
70% of homocysteine is bound to albumin, 30% is oxidized to disulfides, 2% is free
Reference range is 5-15 micromolar (reflects free/non-bound form)
Gender and local population specific reference ranges are strongly recommended, because levels are affected by dietary intake of methionine and vitamins, gender and age (lower in premenopausal women)
High levels may also be due to vitamin B12 deficiency, post-myocardial infarction or stroke
Usually recommended to measure after overnight fast, although this may not be necessary
Also measure 3-6 hours after methionine load of 0.1 g of L-methionine/kg
Must put specimen on ice if plasma separation cannot be performed within 30 minutes, because homocysteine is produced and exported by red blood cells and levels rise after collection in EDTA-anticoagulated tubes; alternatively can use acid citrate tubes and hold for up to 6 hours
Methodology: reduce all forms of homocysteine to free homocysteine, then quantify using either (a) high performance liquid chromatography; (b) fluorescence based immunoassay (Abbott’s IMx analyzer) - reduce using dithiothreitol, then convert to S-adenosyl-L-homocysteine (SAH) via SAH hydrolase; SAH is measured with monoclonal antibody and fluorescent tracer; (c) conventional amino acid analyzer with separation column (slow, but can also detect related amino acids, such as methionine, cystathionine, cysteine)
References: Archives 2002;126:1367
Hypercoagulation panel
Panels are useful to identify all factors predisposing to thrombosis
Laboratory must be notified of therapeutic anticoagulants (heparin, warfarin, danaparoid, hirudin, argatroban)
Venous thrombosis panel typically includes assays for activated protein C resistance (factor V Leiden), protein C, protein S, antithrombin, prothrombin G20210A mutation assay, antiphospholipid antibodies, homocysteine; less common are assays for plasminogen, dysfibrinogenemia, heparin cofactor II or platelet hyperaggregability
Arterial thrombosis panel includes antiphospholipid antibodies, homocysteine levels, lipoprotein (a) [if arterial thrombosis occurs with coronary artery disease, myocardial infarction or stroke]
International normalized ration (INR)
Used to standardize prothrombin time (PT) results for patients taking coumadin (warfarin)
Therapeutic goal is value of 2-3
Intended to make comparisons similar between different labs by compensating for variable thromboplastins used in PT test
Defined as patient PT divided by mean normal PT
Results can be improved with a calibration curve (Archives 2004;128:308)
Results are affected by different thromboplastin reagents, not by storage at room temperature for up to 24 hours (Archives 1998;122:972)
References: J Clin Path 2003;56:48 (recommendations for reporting), J Clin Path 2002;55:845 (patient self testing)
International sensitivity index (ISI)
Measure of sensitivity of particular PT reagent - determined by manufacturer
Used to resolve interlaboratory variations in PT
Different PT reagents have different sensitivities to factor deficiencies
High ISI (3.0) means insensitive reagent vs. low ISI (1.0) means sensitive reagent
References: Archives 2004;128:308 (ISI calibration), J Clin Path 2003;56:114 (ISI calibration for home PT monitors)
Low molecular weight heparin (LMWH)
Recommended to monitor using chromogenic antifactor Xa assay on specimens obtained up to 4 hours after subcutaneous injection of LMWH
Recommended to use different calibrations for LMWH and unfractionated heparin, and to establish calibration curves for each lot and type of LMWH
Don’t use PTT to monitor because LMWH doesn’t affect thrombin or factor IXa
Lupus anticoagulant
Also called lupus inhibitor
One of the two main types of antiphospholipid antibodies (other is anticardiolipin antibodies)
Common in patients with systemic lupus erythematosus
May cause increased PTT (not time dependent), increased or normal PT
Prolongs clotting times by binding to phospholipids cofactors in coagulation cascade (note: often not true for HIV+ patients, Archives 1993;117:595)
Indications: patients with venous thromboembolism (particularly if no family history or associated with autoimmune disease); unexplained stroke (young person or autoimmune disease), cerebral venous thrombosis, recurrent or late pregnancy loss; may be considered for arterial thrombosis (particularly in young patient or no documented atherosclerosis)
Specimen: plasma (citrate tube)
Methodology: all are clotting time based - (a) Russell viper venom time (sensitive to abnormalities in factors X and V, diluted for screening), (b) kaolin clotting time, (c) dilute PT (tissue thromboplastin inhibition test), (d) PTT-based assays (should have low concentration of phospholipids to enhance sensitivity), (e) Textarin (obtained from venomous Australian snake, not sensitive to abnormalities of factor X but sensitive to abnormalities of factor V), (f) Taipan venom (insensitive to abnormalities of factors X or V)
Note: all venom assays are sensitive to abnormalities in factor II, calcium and platelets
Use of commercially available, integrated test systems is recommended: Staclot procedure - (1) add diluent to tube 1 and egg phosphatidylethanolamine to tube 2; (2) add platelet poor plasma with polybrene (neutralizes heparin) to both tubes, incubate and add PTT reagent; PTT in tube 2 should be 12+ seconds shorter than tube 1 to be a positive test for lupus anticoagulant
To demonstrate persistence, positive test must be confirmed by repeat testing after 6 weeks
Screening assay has low concentration of phospholipids to enhance sensitivity; should have platelet count less than 10K
Abnormal (prolonged) PTT results are repeated after mixing with equal amount of normal platelet-poor plasma; continued prolongation of clotting time indicates an inhibitor (not a factor deficiency); confirmed by adding excess phospholipids, which should shorten clotting time towards normal; must also rule out factor VIII inhibitors, heparin, other coagulopathies
Values prolonged by bivalirudin, lepirudin, argatroban, and fondaparinux (Archives 2004;128:1142)
Results vary based on dilutions in factor XII, XI, IX and VIII assays
May be mistaken for a factor VIII inhibitor if dilutions to abnormal factor assays are not done
Don’t test patients being treated with anticoagulants (or interpret with caution)
References: Archives 2002;126:1424, CAP Today; January 2003-warfarin monitoring
Mixing studies
Used to determine if etiology of prolonged PT or PTT is due to a factor deficiency or an inhibitor
Laboratory should be notified of presence of therapeutic anticoagulant
Add heparinase to remove any heparin present (or perform thrombin time to check for even small amounts of heparin)
Methodology: add patient plasma to equal volume of normal plasma and repeat PTT
Prolonged PTT becomes normal after mixing study and stays normal after 2 hours: indicates factor deficiency; perform assays for factors VIII, IX, XI and XII; if PT also prolonged, consider assays for common pathway factors
Prolonged PTT remains prolonged after mixing study: indicates inhibitor; most common is lupus anticoagulant; also therapeutic anticoagulant; rarely due to inhibitors to factors IX, XI or XII
Prolonged PTT becomes normal after mixing study but prolonged after 1-2 hour incubation: indicates factor VIII inhibitor, rarely factor V inhibitor
Plasminogen assay
Either functional (based on plasmin activity) or immunologic (based on concentration of plasminogen antigen)
Functional assays: determine plasmin enzyme activity with plasmin-specific chromogenic substrate; add streptokinase to patient plasma, complex cleaves a chromogen releasing a colored compound; color is measured spectrophotometrically, and is proportional to plasminogen in sample; expressed as percentage of normal plasma (reference range 75-130%)
Immunologic assays: radial immunodiffusion methods; used if dysplasminogenemia is being evaluated; ratio of functional activity to antigen is significantly decreased compared to controls
Plasminogen levels are increased by oral contraceptives (which increase cholesterol levels), pregnancy, acute phase reactions
Plasminogen levels are decreased by liver disease, thrombolytic therapy, DIC; newborns have levels that are 60% of adults, increase to adult values by age 6 months
Indications: patients with familial venous thrombosis but no evidence of other hypercoagulable states, occasionally used to monitor thrombolytic therapy or for patients with ligneous conjunctivitis
Plasminogen activator antigen-1
Uncommon test; perform if strong evidence of familial bleeding disorder but normal results for von Willebrand disease or if unexplained premature myocardial infarction
Must establish appropriate reference ranges and minimize complex formation between PAI1 and t-PA
Not a known risk factor for hypercoagulability (Archives 2002;126:1401), although high levels are associated with arterial thrombosis; low levels are associated with rare familial bleeding disorder
Has circadian rhythm, with highest values in morning; in one study, mean level was 23 ng/mL at 9 am vs. 10 ng/mL at 4 pm; also is acute phase reactant, so don’t measure immediately following thrombosis; also elevated during pregnancy
Collection: collect blood from steadily flowing venipuncture, discard first 3-5 mL (if this is the only test), avoid platelet contamination of plasma (platelets contain PAI1) by separating plasma from cells or storing on ice
Reject specimen if antifibrinolytic agent is present in specimen
Reference range: 4-40 ng/mL for antigen assay, 0-12 units/mL for functional assay
Functional assay: add patient plasma to known amount of urokinase/tPA, which binds to patient PAI1; residual urokinase is detected by adding plasminogen, which converts it to plasmin, which cleaves a chromogenic substrate; amount of released color is inversely proportional to patient PAI1 (note: inhibitors of antiplasmin and plasmin are present to prevent their interference)
ELISA (antigen) assay: also available
Platelet aggregation studies
Used to assess platelet function if a familiar bleeding disorder is suspected, but the PT, PTT, platelet count and von Willebrand tests are normal (which is unusual)
Includes platelet responses to adenoside diphosphate, epinephrine, collagen, ristocetin and arachidonic acid
Usually 60% or more platelets aggregate with the above agonists, but not spontaneously; aggregation is decreased in newborns
Methodology: centrifuge citrated plasma gently to draw red and white blood cells into a pellet, which leaves platelets suspended in the plasma; then add various agonists and a control (no agonist, to measure spontaneous aggregation), and measure platelet aggregation with an aggregometer (which measures optical density)
Abnormalities are often due to medications (aspirin - affects arachidonate aggregation; other platelet-inhibiting agents); also uremia, monoclonal gammopathy, myeloproliferative disorders
Hereditary disorders: consider in patients with bleeding histories, no obvious acquired cause, but abnormal platelet aggregation study repeated at least once, same abnormality in family members; may be a platelet storage pool disorder (deficiency in alpha or dense platelet granules), Glanzmann thombasthenia (deficiency of platelet glycoprotein IIb/IIIa, reduced aggregation by all agonists except ristocetin), Bernard-Soulier disease (deficiency of platelet glycoprotein Ib, causes decreased ristocetin-induced aggregation only)
Platelet antibodies
More detailed discussion in platelet chapter (pending)
Either autoimmune (idiopathic thrombocytopenic purpura), alloimmune (neonatal alloimmune thrombocytopenia, post-transfusion purpura, platelet transfusion refractoriness) or heparin-induced
ELISA: test for specific antiplatelet antibodies; antigen of interest is bound to surface of microtiter plate, then add patient plasma, antibody will bind to antigen
Antigen capture immunoassay: specific antigens are bound to solid phase, then add patient serum, patient antibodies will bind to antigens
Platelet antigen typing by antigen capture immunoassays: patient’s platelet antigens are immobilized by monoclonal antibodies onto a solid phase; then add antibodies of known specificity
Flow cytometry: may be used
Lymphocytotoxicity assay: determine percent reactive antibody (HLA antibodies in patients who are refractory to platelet transfusions)
Polymerase chain reaction: can be used to identify patient’s platelet antigens
Platelet antibody disorders
Drug-induced thrombocytopenia: detected by serotonin release assay (add patient plasma/serum plus drug and platelets with radiolabeled serotonin; drug antibodies, if present, stimulate platelets and radioactive serotonin is released); also detected with flow cytometry; offending drugs include quinine and quidinine, sulfonamides, sulfonylureas, gold salts, salicylates; mechanism is either nonimmune (marrow suppression or nonimmune destruction) or immune (platelet counts due to immune causes may drop to < 10K, return to normal within 7 days of stopping offending drug)
Idiopathic thrombocytopenic purpura (ITP): autoantibody against platelets, usually directed against GP IIb/IIIa, less commonly GP Ib/IX; diagnosis of exclusion; usually resolves in children but is chronic in adults; tests to order include peripheral blood smear, CBC, HIV, thyroid function tests, liver function tests, bone marrow biopsy
Neonatal alloimmune thrombocytopenia (NAIT): incidence of 1 per 1-5K live births; father and newborn have antigen that mother lacks, mother produces antibodies to this antigen (usually PI-A1 component of GP IIb/IIIa) which crosses the placenta and destroys fetal platelets; newborn platelet counts are <100K at birth, return to normal within 2 weeks
Platelet refractoriness: in thrombocytopenic patients with multiple platelet transfusions, due to formation of HLA-A, HLA-B or less commonly ABO antibodies that destroy transfused platelets
Post-transfusion purpura: patient has antibody directed against transfused platelet antigen absent on patient’s platelets; for unknown reasons, these antibodies also destroy platelet’s own antigens; antigen is most commonly PI-A1 component of GP IIb/IIIa; patients have sudden onset of severe thrombocytopenia 5-12 days after transfusion of platelet product, resolves 14 days after transfusion
Platelet hyperaggregation studies
Hyperaggregation may be associated with hypercoagulability, including myocardial infarction, strokes, venous thrombosis
Tested patients should have abstained from aspirin, NSAIDs or platelet-inhibiting drugs for 7 days prior to testing
Indications: patients with unexplained hypercoagulability and normal values in hypercoagulation panel
Methodology: similar to platelet aggregation; centrifuge citrated plasma gently to draw red and white blood cells into a pellet, which leaves platelets suspended in the plasma; then add various agonists at multiple low concentrations and a control (no agonist, to measure spontaneous aggregation), and measure platelet aggregation with an aggregometer (which measures optical density); must carefully evaluate patient’s use of medications (including over the counter); must compare to normal control, and results can be subjective
Prekallikrein assay
Screening assays: preincubate PTT sample for 10 minutes prior to adding calcium; a prolonged PTT that shortens after the 10 minute preincubation is suspicious for prekallikrein deficiency
PTT performed with elagic acid as the intrinsic pathway activator will be normal in prekallikrein deficiency
Specific assay: preincubate patient plasma with prekallikrein-deficient plasma for 1 minute, then add calcium and perform PTT; prekallikrein level is determine from a standard curve of prekallikrein vs. PTT
Interference is due to hirudin, argatroban, danaparoid, heparin (add heparinase)
Reference range is 60-140% of normal; newborn levels are lower, but increase to near adult levels by age 6 months
Indications: prolonged PTT corrected with mixing study, factors VIII, IX, XI and XII are normal, PT and fibrinogen are normal, lupus anticoagulant assays are negative
Protein C assays
Deficiencies are either quantitative (type I, reduced amount of normal protein) or qualitative (type II, normal amount of defective protein) Assays are either functional (measure protein activity) or antigenic (immunoassays that measure quantity, not function)
Perform functional assay first - if decreased, perform antigenic assay; must exclude acquired causes (below)
Low values should be confirmed on a new specimen
Assays should be performed with platelet poor plasma, using sodium citrate collection tubes
Functional assays are clot-based or chromogenic
Clot based functional assays: detects all known type I and II variants; patient’s protein C is activated by Southern Copperhead venom (Agkistrodon contortrix contrortrix), which degrades synthetic substrate, factor Va or factor VIIIa with clot based PTT assay; the prolongation of clotting time is proportional to the amount of factor activity
PT based assay or amidolytic assays are affected by lupus anticoagulants (raises protein C result), elevations of factor VIII > 200% (decreases the result), acute phase reactions, factor V Leiden mutation (decrease the result); cannot perform on patients taking hirudin or argatroban
Chromogenic functional assays: not affected by lupus anticoagulants, factor VIII levels, factor V Leiden or other coagulation abnormalities that interfere with clot-based functional assays; may not detect qualitative deficiencies detected by clot-based assays; patient’s protein C is activated by snake venom, which cleaves a synthetic substrate, which releases a chromogenic that is measured spectrophotometrically
Antigenic assays: either ELISA, electroimmunoassay (Laurell rocket method) or radioimmunoassay; variable levels, so use 3 standard deviations as cutoff
ELISA: uses antibody to protein C immobilized to microtiter place; add plasma; add secondary anti-protein C antibody coupled to an enzyme for colorimetric detection; use standard curve to determine plasma protein C
Laurell rocket antigenic assay: agarose gel has antibody to protein C; plasma samples are put into wells and electrophoresed; antigen-antibody complexes precipitate during electrophoresis, and height of precipitin arc is proportional to plasma protein C, which is compared to standard curve using pooled normal plasma; may be unable to detect protein C levels < 5%
Radioimmunoassay: similar to ELISA, but uses single, radiolabeled antibody
Values falsely increased by bivalirudin, lepirudin, argatroban, and fondaparinux (Archives 2004;128:1142), lowered by warfarin (must discontinue for 10 days prior to testing)
Reference range: 70-140% of normal; newborns levels are 20-30% of adult values; usually rise to near adult levels by age 6 months, but may remain below adult normal levels until age 10 years
Indications: necrotic skin in newborns days 1-3 of life (purpura fulminas neonatorum, can also test parents also for heterozygosity); evaluation of cause of venous thromboembolism (recommended to use chromogenic protein C assays initially)
Non-indications: screening before oral contraceptives or oral anticoagulants (discontinue for 10 days, or test family members)
Acquired causes of low Protein C levels: more common than hereditary deficiencies - clot formation, surgery, liver disease, coumadin (should be discontinued at least 10-30 days prior to testing), DIC, vitamin K deficiency, vitamin K antagonist therapy, L-asparaginase therapy; repeat protein C test once these conditions are no longer present
Acquired causes of increased Protein C (may mask protein C deficiency): ischemic heart disease, pregnancy, postmenopausal women, hormone replacement therapy, oral contraceptives
References: Archives 2002;126:1337
Protein S assays
Deficiencies are either quantitative (type I, reduced normal protein) or qualitative (type II, normal amount of defective protein)
Assays are either functional (measure protein activity) or antigenic (immunoassays that measure quantity, not function)
Gold standard to measure free protein S or APC cofactor activity of protein S is considered the polyclonal ELISA with or without polyethylene glycol precipitation, although this procedure has poor reproducibility
Perform functional assay first (detects all types of deficiencies)
Functional assays are clot-based, cannot be performed in patients taking hirudin or argatroban
Methodology: clot based protein S method is based on the addition of activated protein C, which in the presence of protein S, accelerates the inhibition of thrombin-activated factors VIII and V; the prolongation of clotting time is proportional to the amount of factor S activity; interference may occur with elevated factor VIII (acute phase reactions or otherwise); values falsely increased by bivalirudin, lepirudin, argatroban, and fondaparinux (Archives 2004;128:1142), lupus anticoagulants
Reference ranges are in nmol/liter (each lab should establish its own, values in acute phase plasma are higher):
Total protein S:- 65% of value in pooled normal human plasma (289-397)
Free protein S: 71-115
C4 binding protein beta+: 228-310
Total C4 binding protein: 257-423
Antigenic assays measure free protein S (functionally active form) or total (bound plus free) protein S - usually 60% of protein S is bound to C4b-binding protein
Free protein S levels in protein S deficient patients are very sensitive to timing, temperature and dilutional conditions of assays compared to normal individuals
Acquired causes of low Protein S levels: more common than hereditary deficiencies - clot formation, surgery, liver disease, coumadin (should be discontinued at least 10 days prior to testing), nephrotic syndrome, DIC, L-asparaginase therapy, any stimulus to acute phase response (increases C4b binding protein, decreases free protein S), newborns (12-60% of adult levels, rise to adult levels by 6 months), women (lower than men before menopause, while taking oral contraceptives, during pregnancy or with hormone replacement therapy), vitamin K antagonist drugs, vitamin K deficiency, elevated factor VIII levels (>200%) in PTT based functional assays, thrombosis; also nephrotic syndrome, varicella infection, HIV infection
Classification of deficiencies: all have low functional protein S; I - also low free and total protein S; II / IIb - also normal free and total protein S; III / IIa - low free but normal total protein S
Prothrombin gene 20210A testing
Mutation in G to A transition at nucleotide 20210 in 3’ untranslated portion of prothrombin gene, which introduces a new Hind III restriction site
Methodology: usually PCR amplification of 3’ untranslated region of prothrombin gene surrounding the 20210 polymorphism, then either gel electrophoresis, radioisotopic probing or restriction endonuclease digestion with Hind III to detect the nucleotide sequence
Can identify heterozygotes and homozygotes
Multiplexed arrays test for factor V Leiden, MTHFR C677T and other sequences
Specimen is whole blood
PT - Prothrombin time
Most commonly performed laboratory coagulation test
Measures clotting time from factor VII activation through fibrin formation (i.e. extrinsic and common pathway)
Used as screening test and to monitor warfarin anticoagulation; can only detect single factor deficiencies if level is 15-45% of normal
Methodology: mix patient plasma with calcium (neutralizes citrate anticoagulant) and thromboplastin (a tissue extract, such as from brain, that contains abundant phospholipids and tissue factor), measure time to clot formation
Anticoagulant is usually 3.2% sodium citrate (recommended by Clinical and Laboratory Standards Institute; 3.8% sodium citrate causes prolonged PT if samples are <80% filed compared to 100% filled; no difference in result with 3.2% citrate between filled volumes of 70% and 100%)
Test should use a thromboplastin that is insensitive to heparin in therapeutic range
Note: Warfarin is monitored using INR (international normalized ratio), which standardizes PT results for patients on oral anticoagulants; goal is INR of 2-3; calculated as patient PT divided by mean normal PT; PT/INR should be checked daily at onset of warfarin use until dose and INR are stable (usually at least a week since half life of factors II and X are long), then decreased gradually to every 4 weeks
May be improved by instrument-specific International Sensitivity Index (ISI) values, in-house calibrators or calibration curves (Archives 2004;128:308); ISI measures sensitivity of PT reagent to factor deficiencies (1.0 is sensitive, 3.0 is insensitive, value determined by manufacturer)
Reference interval should be established using at least 120 subjects for each reference population or subclass, and verified using at least 20 subjects
Usual reference range is 10-14 seconds, up to 16 seconds at birth, decreasing to adult values at age 6 months
Limitations: lupus anticoagulants, use of hirudin or argatroban - must use alternative assays, such as chromogenic factor X assays
Prolonged PT: usually due to deficiencies of factors I (fibrinogen), II, V, VII, X, less commonly due to an inhibitor or anticoagulant (heparin, hirudin, argatroban), rarely lupus anticoagulant or specific factor inhibitor
Prolonged PT with normal PTT: warfarin or vitamin K deficiency (decreases function of factors II, VII, IX, X, protein C, protein S), liver dysfunction (decreases hepatic synthesis of all coagulation factors except factor VIII), DIC
Markedly prolonged values may be due to long acting warfarin-like rodenticide toxicity (Archives 2004;128:e181)
References: Archives 1997;121:956 (INR differs with 3.8 vs. 3.2% citrate), CAP today; March 2005-home monitoring
Algorithms for working up a prolonged PTT:
(1) add heparinase; if PT corrects to normal, prolongation is due to presence of heparin
(2) mixing study (determine if etiology if factor deficiency or factor inhibitor); mix patient plasma with equal amount of normal plasma and determine the PT of the mixture after incubation for 2 hours
(a) if PT of mixture is normal, prolonged PT is due to factor deficiency; do assays for factors I, II, V, VII, X
(b) if PT of mixture is still prolonged, suggests presence of inhibitor (rare)
(c) if PTT of mixture is initially normal but becomes prolonged after incubation for 1-2 hours, may be due to factor V inhibitor (rare)
PTT - Partial thromboplastin time
Also called activated partial thromboplastin time (aPTT)
Second most commonly performed coagulation test (after PT)
Measures clotting time from factor XII activation through fibrin formation (i.e. intrinsic and common pathway); more sensitive to intrinsic factor deficiencies
Methodology: mix patient plasma with excess calcium (to counteract the citrate anticoagulant) and phospholipid (called partial thromboplastin since tissue factor is not present) and intrinsic pathway activator such as silica, kaolin, celite or elagic acid; after drawing, invert gently to mix
Used to monitor heparin or direct thrombin inhibitors such as hirudin; target ratio is 1.5 to 3.0 (compared to nonheparinized samples)
Incorrect values may cause bleeding, thrombosis, morbidity or death
3.2% citrate tube is recommended; use of 3.8% citrate as anticoagulant causes prolonged aPTT if samples are <90% filed compared to 100% filled ( no difference in result with 3.2% citrate between filled volumes of 60% and 100%)
Quality control: therapeutic range for heparin should be determined specific to each laboratory’s reagent and instrument system, and redetermined if method changes; determine by comparing ex vivo specimens preferably with an appropriated validated heparin assay or with a previously calibrated PTT specimen using a method to control for reagent drift; determine equivalence using ex vivo plasma samples obtained from patients treated with unfractionated heparin, not spiked in vitro heparinized plasma samples
Can assay heparinized samples up to 4 hours after phlebotomy if centrifuged within 1 hour of collection; have shorter PTT if stored uncentrifuged at room temperature (up to 50% decrease at 4 hours), due to release of PF4 from platelets, which neutralizes heparin
Markedly prolonged values may be due to long acting warfarin-like rodenticide toxicity (Archives 2004;128:e181)
Interpretation: values are normally higher in newborns (up to 55 seconds), decreases to adult levels at age 6 months; values are smaller with acute phase reactions, which elevate Factor VIII levels
References: CAP Today; October 2004 (validating heparin sensitivity of PTT); Archives 1997;121:956 (INR differs with 3.8 vs. 3.2% citrate)
Algorithms for working up a prolonged PTT:
(1) add heparinase; if PTT corrects to normal, prolongation is due to presence of heparin
(2) mixing study (determine if etiology is factor deficiency or factor inhibitor); mix patient plasma with equal amount of normal plasma and determine the PTT of the mixture after incubation for 2 hours
(a) if PTT of mixture is normal, prolonged PTT is likely due to factor deficiency; do assays for factors VIII, IX, XI and XII; if PT is also prolonged, consider common pathway factor assays also
(b) if PTT of mixture is still prolonged, suggests presence of inhibitor, usually lupus coagulant; perform lupus coagulant assay; also possible if heparin is present (should have tested for in step (1) above) or rare factor inhibitors
(c) if PTT of mixture is initially normal but becomes prolonged after incubation for 1-2 hours, may be due to factor VIII inhibitor; perform factor VIII assay - if decreased, perform assay for factor VIII inhibitor
Reptilase time
Clotting time similar to thrombin time, but uses snake venom (Reptilase) instead of thrombin
Measure rate of fibrin clot formation after addition of reptilase to citrated plasma
Generates a fibrin clot by cleaving fibrinopeptide A from fibrinogen
Prolonged by decreased or dysfunctional fibrinogen, or high levels of fibrin degradation products; also amyloidosis (inhibits fibrinogen conversion to fibrin)
Used to diagnose dysfibrinogenemia (also thrombin time)
Not prolonged by heparin or hirudin (unlike thrombin time)
References: Mass General handbook
Thrombin time
Measures rate of fibrin clot formation after addition of standard concentration of thrombin to citrated plasma; thrombin cleaves fibrinogen, releasing fibrinopeptides A and B, and converting fibrinogen to fibrin
Useful to diagnose dysfibrinogenemia after more common disorders are excluded
Reference range: 10-13 or 16-24 seconds, depending on reaction conditions and thrombin concentration
Prolonged if even small amounts of heparin, hirudin or argatroban anticoagulants are present
Also prolonged with dysfibrinogenemia, amyloidosis (inhibits fibrinogen conversion to fibrin), DIC, thrombolytic therapy, thrombin inhibitors in patients exposed to bovine thrombin
tPA
Methodology: must first inhibit interaction of tPA with PAI1 (its functional inhibitor) by acidifying plasma; determine activity by measuring plasmin activity from conversion of plasminogen
Not recommended for routine clinical laboratories due to complexity
Can also measure tPA plasma concentration by ELISA or other immunologic assays
Resting level is usually low, not clinically significant
Post-stimulation level (such as after venous occlusion for 10 minutes) may be more useful
von Willebrand disease testing - general
Often need to repeat tests, because von Willebrand factor and factor VIII are elevated during acute phase reactions, pregnancy, estrogen use and in newborns - can measure fibrinogen (acute phase reactant) to determine if acute phase condition exists
Tests: von Willebrand factor antigen assay, von Willebrand factor activity (ristocetin cofactor activity), factor VIII levels, fibrinogen (or other acute phase reaction marker), multimer analysis
Interpretation:
- All results normal (considering ABO blood type) - unlikely to have vWD if no acute phase reaction, pregnancy, estrogen use, newborn
- All results normal but elevated fibrinogen / factor VIII - acute phase reaction may mask abnormalities; repeat when fibrinogen and factor VIII levels are normal
- Reduced antigen, activity, factor VIII - likely type 1 vWD
- Severely reduced (<10%) or undetectable antigen, activity, factor VIII - likely type 3 vWD
- Activity reduced more than antigen and factor VIII - possibly type 2 vWD; perform multimer analysis and low dose ristocetin cofactor
. normal multimer analysis - likely type 2M vWD
. missing high molecular weight multimers - likely type 2A vWD
. missing high and intermediate molecular weight multimers - likely type 2B or platelet type vWD
. increased low dose ristocetin aggregation - likely type 2B or platelet type vWD
. normal or decreased low dose ristocetin aggregation - not type 2B or platelet type vWD
. reduced factor VIII (5-40%), normal activity and activity - possibly type 2N vWD or in males, mild hemophilia A; also possibly factor VIII degradation due to processing delay
von Willebrand factor antigen assay (vWF)
Levels can increase 2-3x with injury, infection or other acute phase reactant stimulus (30% level at baseline can increase to 90% by the time the patient is tested); can determine presence of acute phase reaction by measuring fibrinogen
Reference range is higher in children < 6 months old than adults (abnormal value in 3 month old may be normal for an adult)
Minor injuries may produce major bleeds in children, leading to false accusations of child abuse
Type O patients have significantly lower vWF antigen levels (75%) compared to type A (106%), type B (117%), type AB (123%); although bleeding symptoms may depend on vWF antigen levels regardless of ABO type
Methodology: (a) ELISA assay measures quantity of vWF, not function (quality); (b) also latex particles coated with anti-vWF antibodies, measure light absorbance; (c) rocket immunoelectrophoresis
Used to determine if patient with personal or family history of bleeding has von Willebrand disease; also to assist in determining hemophilia A carrier status in females
von Willebrand factor activity
Also called ristocetin cofactor activity
Ristocetin is an antibiotic that causes vWF to bind to and activate platelets
Test measures function of von Willebrand factor
Platelets from healthy individuals are mixed with standard concentrations of ristocetin and patient plasma is added to cause platelet agglutination (measured in aggregometer), which is proportional to the vWF concentration
Used to confirm type 2B von Willebrand’s disease (increased agglutination due to increased affinity of vWF for GPIb); similar results for platelet type von Willebrand’s disease (although the defect is in GPIb)
Note: “aggregation” of platelets implies linkage via fibrinogen and GP IIb/IIIa; ristocetin links platelets through vWF and GP Ib, and appropriate term is actually “agglutination”
Other functional test: collagen-binding ELISA assay, functional vWF binds to collagen and is detected
Low dose ristocetin platelet aggregation assay
To diagnose type 2B von Willebrand disease
Similar to von Willebrand factor activity test, but uses patient’s platelets and lower dose of ristocetin
Platelets from patient are mixed with standard concentrations of ristocetin and patient plasma is added to cause platelet agglutination (measured in aggregometer); increased aggregation in type 2B vWD in this assay due to GP Ib mutation, which increases affinity for vWF
von Willebrand factor multimer analysis
To detect type 2 von Willebrand disease
Involves separation of multimers by size using agarose gel electrophoresis of patient’s plasma
Then detect multimers using radiolabeled or enzyme linked anti-vWF antibody
Normal in von Willebrand’s disease types 1, 2N or 2M (type 1 has reduced quantity of all sizes, but difficult to identify on gel)
No/reduced high molecular weight multimers in types 2A and 2B von Willebrand’s disease
No/reduced intermediate molecular weight multiples in type 2A
No/marked reduction in all multimers in type 3
End of Coagulation chapter/outline
(read full article)
Sources on the web: PatologyOutLines.Com
Related publications: PatologyOutLines.Com
Related documents to download: -
Notes: -
Year: 2005
Title: A NOVEL 14 BASE PAIRS DELETION MUTATION IN EXON 5 ASSOCIATED WITH A188G MUTATION IN EXON 2 OF PLASMINOGEN GENE IN TWO PATIENTS WITH SEVERE HYPOPLASMINOGENEMIA AND LIGNEOUS CONJUNCTIVITIS
Date: - (dd/mm/yy) - 01/01/06
Authors: M.T. Sartori, C. Abati, D. Manfrin, F. Dal Bello, L. Spiezia, A. Casonato, M. Fioretti, G.M. Patrassi, P. Simioni, A. Girolami Dept. Medical and Surgical Sciences, Inst. Microbiology, University of Padua Medical School, Italy
Abstract:
Abstract number: OC2367
Supplement to the journal Thrombosis and Haemostasis, July 2001 (ISSN 0340-6245)
Abstract number: OC2367
Supplement to the journal Thrombosis and Haemostasis, July 2001 (ISSN 0340-6245)
A NOVEL 14 BASE PAIRS DELETION MUTATION IN EXON 5 ASSOCIATED WITH A188G MUTATION IN EXON 2 OF PLASMINOGEN GENE IN TWO PATIENTS WITH SEVERE HYPOPLASMINOGENEMIA AND LIGNEOUS CONJUNCTIVITIS
M.T. Sartori, C. Abati, D. Manfrin, F. Dal Bello, L. Spiezia, A. Casonato, M. Fioretti, G.M. Patrassi, P. Simioni, A. Girolami
Dept. Medical and Surgical Sciences, Inst. Microbiology, University of Padua Medical School, Italy
Severe type I plasminogen deficiency has been identified as the cause of ligneous conjunctivitis, a rare disease characterized by development of fibrin-rich pseudomembranes in the mucosa, especially in the conjunctiva. Several defects in the plasminogen gene leading to low or undetectable plasminogen levels have been recently discovered. Two unrelated female patients, aged 13 (N.1) and 30 (N.2) years, both affected with ligneous conjunctivitis were investigated. Plasminogen antigen (PLG:Ag) and activity (PLG:act) plasma levels and DNA sequence analysis of plasminogen gene were performed. In patient N.1, PLG:Ag and PLG:act values were 15% and 15.8% of normal, respectively; in patient N.2, they were 34% and 32.3% of normal, respectively. DNA analysis demonstrated a 14 bp deletion at position 522 (522-536) in exon 5 of plasminogen gene leading to a TGA stop codon 40 bp downstream of the deletion site. Both patients were heterozygous for this deletion in exon 5. Furthermore, DNA analysis showed a A®G point mutation in both patients at position 188 in exon 2 of plasminogen gene, responsible for an amino acid exchange Lys19Glu. This mutation is located in the proactivation peptide (NH2-terminal) of the plasminogen molecule, 59 amino acids upstream of the Lys77-Lys78 cleavage site. Patient N.1 was heterozygous carrier of the A188G mutation, whereas the patient N.2 was shown to be homozygous. Family studies confirmed the hereditary nature of defects. The double genetic defect found in the propositae significantly reduced but not abolished the synthesis of plasminogen. In patient N.1, a tentative therapeutic approach with oestroprogestinc pill determined a notable increase in PLG activity up to 49%. Patient N.2 developed Cushing's disease due to pituitary adenoma. In this condition, her PLG:Ag and PLG:act levels increased to about 50%, and slowly decreased a few months after surgical excision of the neoplasm. A mild decrease of von Willebrand factor and factor VIII plasma levels, compatible with mild type I von Willebrand disease, was also occasionally discovered in patient N.2, To our knowledge, compound plasminogen deficiency and von Willebrand disease has never been reported. In conclusion, our data demonstrate a double genetic defect, namely a new 14 bp deletion mutation in exon 5 and a A188G point mutation in exon 2, in two patients with hypoplasminogenemia and ligneous conjunctivitis. In the propositae, oestroprogestinc therapy and increased glucocorticoids production significantly influenced gene expression and plasminogen levels.
©2001 Schattauer GmbH, Stuttgart - New York
All rights reserved.
XVIII Congress
The International Society on Thrombosis and Haemostasis
July 6-12, 2001
Paris, France
(read full article)
Sources on the web: http://www.schattauer.de/
Related publications: XVIII Congress The International Society on Thrombosis and Haemostasis July 6-12, 2001 Paris, France
Updated 26 June, 2001
http://www.schattauer.de/
Related documents to download: -
Notes:
Year: 2001
Title: Ligneous conjunctivitis in a patient with plasminogen type I deficiency--case report with review of literature
Date: - (dd/mm/yy) - 01/01/06
Authors: Heinz C; Kremmer S; Externbrink P; Steuhl KP Universitätsaugenklinik Essen, Germany. carsten.heinz@uni-essen.de
Abstract:
Ligneous conjunctivitis in a patient with plasminogen type I deficiency--case report with review of literature
Klin Monatsbl Augenheilkd. 2002; 219(3):156-8 (ISSN: 0023-2165)
Heinz C; Kremmer S; Externbrink P; Steuhl KP
Universitätsaugenklinik Essen, Germany. carsten.heinz@uni-essen.de
BACKGROUND: Ligneous conjunctivitis is a rare chronic pseudomembranous conjunctivitis. It forms nodular masses on the palpebral conjunctiva. Beside the conjunctival affection pseudomembranes can also be found on other mucosal tissues.
PATIENT: We report on a male baby who had a ventriculoperitoneal shunt due to hydrocephalus internus on his fourth day after birth. Recurrent pseudomebranous conjunctivitis started in the first week of life. This was refractory to drug therapy and reoccurred soon after surgical procedure. The analysis of clotting parameters revealed homozygous plasminogen deficiency.
CONCLUSION: Recently type I plasminogen deficiency seems to be a major reason for developing conjunctivitis lignosa. Homozygous and heterozygous mutations in the plasminogen gene are found. At the moment no satisfactory therapy is available. Cases with mild ophthalmological symptoms seem to be positively influenced by a therapy of topical steroids combined with heparin. In severe cases with generalised symptoms systemic therapy with lys-plasminogen is necessary. High costs and poor bioavailability complicate systemic therapy. Improved plasminogen variants for treatment of severe type I plasminogen deficiency would be of great clinical importance.
PreMedline Identifier: 11987044
(read full article)
Sources on the web: MEDSCAPE from WEBMD
Related publications: MEDSCAPE from WEBMD
Related documents to download: -
Notes: -
Year: 2002
There are 35 Articles in 5 pages and your are on page number 3
Click HERE to perform a search. |
 |
Title: Ear involvement in ligneous conjunctivitis: a rarity or an under-diagnosed condition?
Date: - (dd/mm/yy) - 31/12/05
Authors: Hydén D. 1; Latkovic S. 2; Brunk U. 3; Laurent C. 4;
Abstract: Conjunctivitis lignosa, a rare affliction of the conjunctiva, is sometimes associated with other disturbances. We present two children with concurrent conjunctivitis lignosa and ear involvement. In these two cases, there were histopathologically verified ligneous changes of the middle ears. Routine haematoxylin and eosin, van Gieson, periodic acid-Schiff (PAS) and alcian blue staining of specimens from the eyes and middle ears revealed findings typical for ligneous conjunctivitis. In addition, new histochemical and immunohistochemical studies for glycosaminoglycans on specimens from the eyes and middle ears showed that the accumulations of the amorphous, cell-deficient material stained strongly but heterogeneously for hyaluronic acid and weakly but uniformly for keratin sulphate. The staining for other glycosaminoglycans, e.g. chondroitin-4-sulphate and dermatan sulphate was confined to vessels and areas rich in collagen fibres and fibroblasts. In patients with conjunctivitis lignosa, the ear involvement may remain undiagnosed due to its resemblance to secretory otitis media with effusion. Since isolated ear involvement may occur, we advocate biopsies for routine haematoxylin and eosin, and specific staining for hyaluronic acid and keratin sulphate, also in children with protracted, refractory otitis media with atypical effusion.
Affiliations:
1: Department of Otorhinolaryngology, University Hospital, Linköping, Sweden 2: Department of Ophthalmology, University Hospital, Linköping, Sweden
3: Department of Pathology, University Hospital, Linköping, Sweden
4: Deparment of Otorhinolaryngology, Univeristy of Umeå, Sweden
© 2005 Ingenta
( read full article )
Sources on the web: Journal of Laryngology & Otology , Volume 116, Number 6, 1 June 2002, pp. 482-487(6)
Related publications: Royal Society of Medicine Press
Related documents to download: -
Notes: -
Year: 2002
|
 |
|
Title: Ligneous conjunctivitis.
Date: - (dd/mm/yy) - 31/12/05
Authors: Schuster V , Seregard S .
Abstract: Surv Ophthalmol. 2003 Jul-Aug;48(4):369-88
Ligneous conjunctivitis. Related Articles, Links
Schuster V , Seregard S .
Department of Pediatrics, Leipzig University Medical School, Leipzig, Germany.
Ligneous conjunctivitis (McKusick 217090) is a rare form of chronic conjunctivitis characterized by the development of firm fibrin-rich, woody-like pseudomembraneous lesions mainly on the tarsal conjunctivae. Less frequently, similar lesions may occur on other mucous membranes of the body indicating that these manifestations are part of a systemic disease. Histopathological findings from affected humans and (plasminogen-deficient) mice indicate that wound healing, mainly of injured mucosal tissue, is impaired due to markedly decreased (plasmin-mediated) extracellular fibrinolysis. Pseudomembraneous lesions of the eyes and other mucosal tissue mainly contain clotted fibrin(ogen). Actually, systemic plasminogen deficiency has been linked to ligneous conjunctivitis in humans and mice. In one case, ligneous conjunctivitis has been induced by antifibrinolytic treatment with tranexamic acid. Further rare associated disorders of ligneous conjunctivitis are congenital occlusive hydrocephalus and juvenile colloid milium. This review outlines the historical background, clinical characteristics of ligneous conjunctivitis and its associated complications, histological abnormalities of pseudomembraneous lesions, inheritance, hemostasiologic and molecular genetic findings in affected patients, current treatment approaches, and the plasminogen-deficient mouse as an animal model.
PMID: 12850227 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: -
Year: 2003
|
|
|
Title: Ligneous conjunctivitis: a local manifestation of a systemic disorder?
Date: - (dd/mm/yy) - 31/12/05
Authors: Chen S , Wishart M , Hiscott P .
Abstract: J AAPOS. 2000 Oct;4(5):313-5.
Ligneous conjunctivitis: a local manifestation of a systemic disorder?
Chen S , Wishart M , Hiscott P .
Unit of Ophthalmology, University of Liverpool and Royal Liverpool University Hospital, Liverpool, England.
Ligneous conjunctivitis is a descriptive term. It refers to the "woody" consistency of the pseudomembrane that usually forms on the palpebral conjunctiva of those affected. It is rare and probably only one manifestation of a multiorgan, pseudomembranous disease. (1-4) We report a case of ligneous conjunctivitis in which investigation revealed a plasminogen deficiency in the heterozygous range (previously reported only in association with a homozygous plasminogen deficiency). We suggest a strategy for investigating known and new cases of ligneous conjunctivitis and/or pseudomembranous disease.
PMID: 11040483 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: -
Year: 2000
|
|
|
Title: Therapy with a purified plasminogen concentrate in an infant with ligneous conjunctivitis and homozygous plasminogen deficiency.
Date: - (dd/mm/yy) - 31/12/05
Authors: Schott D , Dempfle CE , Beck P , Liermann A , Mohr-Pennert A , Goldner M , Mehlem P , Azuma H , Schuster V , Mingers AM , Schwarz HP , Kramer MD .
Abstract: N Engl J Med. 1998 Dec 3;339(23):1679-86.
Therapy with a purified plasminogen concentrate in an infant with ligneous conjunctivitis and homozygous plasminogen deficiency.
Schott D , Dempfle CE , Beck P , Liermann A , Mohr-Pennert A , Goldner M , Mehlem P , Azuma H , Schuster V , Mingers AM , Schwarz HP , Kramer MD .
Department of Pediatrics, Klinikum Mannheim, University of Heidelberg, Germany.
PMID: 9834305 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: -
Year: 1998
|
|
|
Title: Polymorphonuclear elastase in patients with homozygous type I plasminogen deficiency and ligneous conjunctivitis.
Date: - (dd/mm/yy) - 31/12/05
Authors: Mingers AM , Philapitsch A , Schwarz HP , Zeitler P , Kreth HW .
Abstract: Semin Thromb Hemost. 1998;24(6):605-12.
Polymorphonuclear elastase in patients with homozygous type I plasminogen deficiency and ligneous conjunctivitis.
Mingers AM , Philapitsch A , Schwarz HP , Zeitler P , Kreth HW .
Children's Hospital, University of Wurzburg, Germany.
Laboratory studies were performed on six female patients (ranging in age from 1 to 31 years) with ligneous conjunctivitis, which we regard as a systemic condition consisting of ligneous conjunctivitis and other pseudomembranous lesions. Plasminogen levels were severely reduced in all six patients; five patients were homozygous, and one patient was double heterozygous for type I plasminogen deficiency. Of family members tested, 11 of 12 parents and two of six siblings tested were diagnosed as heterozygous. No thrombotic episodes had occurred in any of the patients. Polymorphonuclear (PMN) elastase protein levels were markedly elevated in all, significantly more so in the homozygous patients (range 88 to 335 ng/mL; normal range, 20+/-10 ng/mL) than in the heterozygous patient (58 ng/mL). Of 11 parents examined, only 1 mother had normal PMN elastase (27 ng/mL, with plasminogen antigen 60% and plasminogen functional activity 86%), whereas values were moderately elevated (range 42 to 110 ng/mL) in the other 10 parents examined. After plasminogen substitution, PMN elastase levels consistently decreased but did not reach normal values. We interpret our findings as indicating that non-plasmin-induced fibrinolytic processes, possibly mediated via elastase, may be intensified in patients with plasminogen deficiency.
PMID: 10066157 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: -
Year: 1998
|
|
|
Title: Ligneous conjunctivitis in a girl with severe type I plasminogen deficiency.
Date: - (dd/mm/yy) - 31/12/05
Authors: Kraft J , Lieb W , Zeitler P , Schuster V .
Abstract: Graefes Arch Clin Exp Ophthalmol. 2000 Sep;238(9):797-800.
Ligneous conjunctivitis in a girl with severe type I plasminogen deficiency.
Kraft J , Lieb W , Zeitler P , Schuster V .
Department of Ophthalmology, Julius Maximilian University, Wurzburg, Germany. janine.kraft@mail.uni-wuerzburg.de
BACKGROUND: Ligneous conjunctivitis is a rare form of chronic recurrent pseudomembranous disease and may be associated with systemic membranous pathological changes. Recently ligneous conjunctivitis has been linked to severe type I plasminogen deficiency. We report on a patient with plasminogen deficiency and severe bilateral ligneous conjunctivitis. A new treatment approach and its outcome in this patient are described.
CASE REPORT: We present the case of a 9-month-old Turkish girl with massive swelling of the eyelids and hard white pseudomembranes on both lids. The conjunctival smear was positive for Streptococcus pneumoniae. The clinical diagnosis was: ligneous conjunctivitis with superinfection. Histological investigation showed fibrin as major component of the pseudomembranes. The coagulation analyses revealed decreased plasminogen activity (<5%; normal 80-120%) and decreased plasminogen antigen (<0.4 mg/dl; normal 6-25 mg/dl). The failure of surgical therapy led to the attempt at treatment with intravenous lys-plasminogen. A significant improvement of the ocular symptoms occurred; stabilization with no recurrent pseudomembranes could be achieved for 6 months after treatment.
DISCUSSION: The initial amelioration of symptoms in our patient after systemic replacement therapy confirms the etiological importance of plasminogen deficiency in the development of ligneous conjunctivitis. Curative treatment of ligneous conjunctivitis is still not available. However, intravenous application of plasminogen offers new possibilities in therapy, although long-term treatment seems necessary.
PMID: 11045349 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: -
Year: 2000
|
|
|
Title: Effective treatment of ligneous conjunctivitis with topical plasminogen.
Date: - (dd/mm/yy) - 31/12/05
Authors: Watts P , Suresh P , Mezer E , Ells A , Albisetti M , Bajzar L , Marzinotto V , Andrew M , Massicotle P , Rootman D .
Abstract:
Am J Ophthalmol. 2002 Apr;133(4):451-5. Related Articles, Links
Erratum in:
Am J Ophthalmol 2002 Aug;134(2):310.
Effective treatment of ligneous conjunctivitis with topical plasminogen.
Watts P , Suresh P , Mezer E , Ells A , Albisetti M , Bajzar L , Marzinotto V , Andrew M , Massicotle P , Rootman D .
Department of Ophthalmology, The Hospital for Sick Children and Toronto Western Hospital, Toronto, Ontario, Canada.
PURPOSE: The etiology of ligneous conjunctivitis is now known to be due to an underlying type 1 plasminogen deficiency. We hereby report the clinical features of three cases and their response to topically administered plasminogen.
DESIGN: Observational case series.
METHODS: Two Caucasian females aged 5 years and an 18-month male of north African descent presented with a membranous conjunctivitis, which recurred after surgical excision. Case 1 presented before the association with plasminogen deficiency was known with a bilateral chronic membranous mucopurulent conjunctivitis from the age of 14 months associated with bronchiolitis and gingival hyperplasia. A diagnosis of ligneous conjunctivitis was entertained and a number of drops were instituted. At the age of 4 years plasminogen levels were ordered. Case 2 presented at the age of 4 years with a unilateral chronic membranous conjunctivitis. Plasminogen levels were requested as soon as a diagnosis of ligneous conjunctivitis was suspected. Case 3 was born with congenital hydrocephalus. Conjunctivitis was treated with antibiotics from the age of 1 month. He presented to the eye clinic at the age of 5 months when a clinical diagnosis of ligneous conjunctivitis was entertained and treated with a number of medications. Plasminogen levels were available at 9 months of age.
RESULTS: The two female patients returned plasminogen levels of 0.25 U/ml and 0.3 U/ml, well below the normal level of 0.7-1.0 U/ml. Functional plasminogen levels in the male infant were not recordable with plasminogen antigen levels of 0.125 U/ml (normal range, 0.52-1.82). All cases have responded well to excision of the membranes and institution of topical plasminogen drops. There has been no recurrence with more than 12 months' follow-up.
CONCLUSIONS: With the knowledge of the etiology of ligneous conjunctivitis, efforts are underway to identify the best method of delivery of plasminogen. Topical plasminogen concentrate from fresh frozen plasma holds promise as the definitive treatment for this chronic membranous conjunctivitis
PMID: 11931777 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: -
Year: 2002 |
|
Title: [Ligneous conjunctivitis in a patient with plasminogen type I deficiency--case report with review of literature]
Date: - (dd/mm/yy) - 31/12/05
Authors: Heinz C , Kremmer S , Externbrink P , Steuhl KP .
Abstract: Klin Monatsbl Augenheilkd. 2002 Mar;219(3):156-8
Ligneous conjunctivitis in a patient with plasminogen type I deficiency--case report with review of literature]
[Article in German]
Heinz C , Kremmer S , Externbrink P , Steuhl KP .
Universitatsaugenklinik Essen, Germany. carsten.heinz@uni-essen.de
BACKGROUND: Ligneous conjunctivitis is a rare chronic pseudomembranous conjunctivitis. It forms nodular masses on the palpebral conjunctiva. Beside the conjunctival affection pseudomembranes can also be found on other mucosal tissues.
PATIENT: We report on a male baby who had a ventriculoperitoneal shunt due to hydrocephalus internus on his fourth day after birth. Recurrent pseudomebranous conjunctivitis started in the first week of life. This was refractory to drug therapy and reoccurred soon after surgical procedure. The analysis of clotting parameters revealed homozygous plasminogen deficiency.
CONCLUSION: Recently type I plasminogen deficiency seems to be a major reason for developing conjunctivitis lignosa. Homozygous and heterozygous mutations in the plasminogen gene are found. At the moment no satisfactory therapy is available. Cases with mild ophthalmological symptoms seem to be positively influenced by a therapy of topical steroids combined with heparin. In severe cases with generalised symptoms systemic therapy with lys-plasminogen is necessary. High costs and poor bioavailability complicate systemic therapy. Improved plasminogen variants for treatment of severe type I plasminogen deficiency would be of great clinical importance.
PMID: 11987044 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: -
Year: 2002 |
|
|
Title: Contraceptive pills induce an improvement in congenital hypoplasminogenemia in two unrelated patients with ligneous conjunctivitis.
Date: - (dd/mm/yy) - 31/12/05
Authors: Teresa Sartori M , Saggiorato G , Pellati D , Casonato A , Spiezia L , Pontara E , Gavasso S , Girolami A .
Abstract: Thromb Haemost. 2003 Jul;90(1):86-91.
Comment in:
Thromb Haemost. 2004 Apr;91(4):830-1; author reply 832.
Contraceptive pills induce an improvement in congenital hypoplasminogenemia in two unrelated patients with ligneous conjunctivitis.
Teresa Sartori M , Saggiorato G , Pellati D , Casonato A , Spiezia L , Pontara E , Gavasso S , Girolami A .
Department of Medical and Surgical Sciences, 2nd Chair of Internal Medicine, Padova, Italy. mtsart@unipd.it
Severe type I plasminogen deficiency is the underlying cause of ligneous conjunctivitis, a rare disease characterized by wood-like pseudomembranes developing on the ocular and extraocular mucosa. Two unrelated female patients with ligneous conjunctivitis and moderate hypoplasminogenemia are described. Being of fertile age, they were treated with oral contraceptives, which determined a marked increase in plasminogen levels. Moreover, a palpebral pseudomembrane stopped growing in one patient and disappeared completely in the other while on the estroprogestinic treatment. In patient n. 2, who also suffered from von Willebrand's disease, prior Cushing's disease induced an increase in both von Willebrand factor and plasminogen levels, which dropped after curative hypophysectomy. Genetic plasminogen study showed a 19Lys>Glu mutation in a heterozygous state in the first proposita and in a homozygous state in the second proband. In addition, both index patients were homozygous for a new intron F-14T>G mutation, which was found to reduce the acceptor splicing site prediction score. In conclusion, oral contraceptive therapy may improve plasminogen deficiency and deserves attention as an alternative therapeutic approach in selected cases of ligneous conjunctivitis with low, but not absent, plasminogen synthesis.
PMID: 12876630 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: -
Year: 2003
|
|
|
Title: Treatment of ligneous conjunctivitis with topical plasmin and topical plasminogen.
Date: - (dd/mm/yy) - 31/12/05
Authors: Heidemann DG , Williams GA , Hartzer M , Ohanian A , Citron ME .
Abstract:
Cornea. 2003 Nov;22(8):760-2.
Treatment of ligneous conjunctivitis with topical plasmin and topical plasminogen.
Heidemann DG , Williams GA , Hartzer M , Ohanian A , Citron ME .
Department of Ophthalmology, William Beaumont Hospital, Royal Oak, Michigan, USA. SMHLAD@aol.com
PURPOSE: To describe treatment of a child with recalcitrant ligneous conjunctivitis secondary to a systemic plasminogen deficiency.
DESIGN: Interventional case report.
METHODS: A seven-year-old boy developed severe unilateral membranous conjunctivitis recalcitrant to surgical debridement and treatment with topical prednisone, topical cyclosporine, and oral prednisone. Systemic evaluation revealed a severe plasminogen deficiency.
RESULTS: Treatment with surgical debridement and topical plasmin was ineffective and resulted in prompt recurrence of dense conjunctival membranes. Treatment with topical plasminogen resulted in dramatic improvement and complete resolution of the membranes.
CONCLUSIONS: Ligneous conjunctivitis is secondary to a systemic plasminogen deficiency. Treatment with topical plasminogen resulted in prompt resolution of the membranes. Treatment with topical plasmin was ineffective.
PMID: 14576528 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes:
Year: 2003 |
|
|
Title: Prevention of ligneous conjunctivitis by topical and subconjunctival fresh frozen plasma.
Date: - (dd/mm/yy) - 31/12/05
Authors: Tabbara KF .
Abstract:
Am J Ophthalmol. 2004 Aug;138(2):299-300.
Prevention of ligneous conjunctivitis by topical and subconjunctival fresh frozen plasma.
Tabbara KF .
The Eye Center and The Eye Foundation for Research in Ophthalmology, Riyadh, Saudi Arabia. k.tabbara@nesma.net.sa
PURPOSE: To present a case of ligneous conjunctivitis where the recurrence of membranous conjunctivitis was prevented by subconjunctival and topical instillation of fresh frozen plasma.
DESIGN: Interventional case report.
METHODS: A case of ligneous conjunctivitis with multiple recurrences since the age of 3 years developed recurrent membranous conjunctivitis after transconjunctival levator recession. Blood plasminogen activity was determined. The membrane was excised, and the membrane reappeared 4 days later. The patient was treated with excision of the membrane and subconjunctival injection of fresh frozen plasma and topical fresh frozen plasma. Plasminogen activity of the fresh frozen plasma was normal.
RESULTS: Plasminogen blood functional activity was 52% (normal is 80%-120%). The patient had complete remission with no recurrences of membranous conjunctivitis after topical and subconjunctival fresh frozen plasma.
CONCLUSIONS: Prophylactic use of topical and subconjunctival fresh frozen plasma may help in the prevention of membranes in susceptible patients with plasminogen deficiency.
PMID: 15289146 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: -
Year: 2004 |
|
|
Title: Amniotic membrane transplantation in a case of ligneous conjunctivitis.
Date: - (dd/mm/yy) - 31/12/05
Authors: Barabino S , Rolando M .
Abstract:
Comment on:
Am J Ophthalmol. 2004 Apr;137(4):752-3.
Therapeutic approaches in the treatment of ligneous conjunctivitis, the most common clinical manifestation of a systemic disease, caused by severe type I plasminogen deficiency.
Tefs K , Hugle B , Schuster V .
Amniotic membrane transplantation in a case of ligneous conjunctivitis.
Barabino S , Rolando M .
Department of Neurosciences, Ophthalmology and Genetics, University of Genoa, Genoa, Italy. barabino@vision.eri.harvard.edu
PURPOSE: To report a case of ligneous conjunctivitis treated with amniotic membrane transplantation. DESIGN: Interventional case report. METHODS: A 44-year-old woman presented with woodlike lesions in the upper and lower tarsal conjunctiva, blepharoptosis, and reduced visual acuity in the left eye. After confirmation of the diagnosis of ligneous conjunctivitis, she underwent amniotic membrane transplantation. RESULTS: At the 2-month, 4-month, and 6-month examinations, the tarsal conjunctiva appeared free from membranes. At 8 months, the patient underwent amniotic membrane transplantation for small recurrences. At the 36-month examination, no membranes were evident, and visual acuity was 20/20. CONCLUSIONS: In this first report of amniotic membrane transplantation in a case of ligneous conjunctivitis, we found that conjunctival reconstruction shows promising results in this difficult-to-manage disease.
PMID: 15059718 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
- NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: Comment in: Am J Ophthalmol. 2004 Oct;138(4):699; author reply 699-700.
Year: 2004 |
|
|
Title: [Ligneous conjunctivitis: complication of inborn plasminogen deficiency (a case report)] [Article in Czech]
Date: - (dd/mm/yy) - 31/12/05
Authors: Dostalek M , Krasny J , Spicka I , Sach J .
Abstract:
Cesk Slov Oftalmol. 2005 Jan;61(1):38-49.
[Ligneous conjunctivitis: complication of inborn plasminogen deficiency (a case report)]
[Article in Czech]
Dostalek M , Krasny J , Spicka I , Sach J .
Ortopticka cast, Ocni oddeleni, Nemocnice, Litomysl.
Authors refer about detailed analysis of ten years follow up of a child patient with ligneous conjunctivitis. They document presence of all typical eye findings (especially recurrent formation of granulomatous pseudotumors in affected mucous membrane) related to this rare pseudomembranous conjunctivitis. The clinical picture of the disease includes plasminogen deficiency, a factor newly considered as primary cause of the disease. The diagnosis was confirmed histologicaly by repeated probatory excisions. Pseudomembranous inflammation with mixed inflammatory infiltrate containing large amount of elements of chronical as well as acute inflammatory reaction is typical. Granuloma with the accumulation of the PAS-positive amorphous matrix with high content of the fibrin and with the network of newly formed vessels is the component of the inflammatory picture. The treatment was based on successively discovered knowledge of the possible etiopathogenesis of the disease. Only the ninth, last surgical procedure induced longer-term remission, which lasts sixteen months until now. The granuloma excision was combined with the mitomicin application on the wound surface and a conjunctivoplasty. During the postoperative period, the ointment with heparin, corticosteroid and antibiotic was applied. The purpose of the mitomicin use is to slow down the fibroproliferative reparative reaction. Covering of the wound surface decreases the number of microtraumas on the uneven postoperative scleral surface. Heparin in the interstitial tissue of the wound surface blocks the conversion of fibrinogen to fibrin.
PMID: 15782857 [PubMed - indexed for MEDLINE]
( read full article )
Sources on the web:
NCBI
- NLM
- NIH
- Department of Health & Human Services
Related publications:
NCBI
- NLM
- NIH
- Department of Health & Human Services
Related documents to download: -
Notes: -
Year: 2005 |
Title: plasminogen therapy Ligneous conjunctivitis
Date: - (dd/mm/yy) - 28/12/05
Authors: AlltheWeb find it all (search)
Abstract:
NEJM -- Therapy with a Purified Plasminogen Concentrate in an Infant with Ligneous Conjunctivitis and Homozygous ...
Original Article from The New England Journal of Medicine -- Therapy with a Purified Plasminogen Concentrate in an Infant with Ligneous Conjunctivitis and Homozygous Plasminogen Deficiency
more hits from: http://content.nejm.org/cgi/content/short/339/23/1679 - 22 KB
Therapy with a purified plasminogen concentrate in an infant with ligneous conjunctivitis and homozygous plasminogen...
No abstract available
more hits from: http://www.medscape.com/medline/abstract/9834305 - 24 KB
MR Frame 3
LIGNEOUS CONJUNCTIVITIS. Definition. Ligneous conjunctivitis is a rare chronic conjunctivitis in which a thick nodular mass replaces the normal mucosa. ... term plasminogen-replacement therapy led to complete regression of the ligneous conjunctivitis and normalized ... that severe plasminogen deficiency causes ligneous conjunctivitis. ( ...
more hits from: http://malattierare.pediatria.unipd.it/pubblicaMR/mr_frame_ing.asp?mr=77 - 9 KB
Ligneous Conjunctivitis
Web resources on Ligneous Conjunctivitis. ... Conjunctivitis Ligneous,Ligneous ... Ligneous conjunctivitis. conjunctivitis type. ...http://omni.ac.uk/browse/mesh/detail/C0009763L0009 TYPE I PLASMINOGEN DEFICIENCY. NEJM -- Therapy with a Purified Plasminogen ...
more hits from: http://health.cancer-help.org/web/Ligneous_Conjunctivitis.html - 15 KB
[Ligneous conjunctivitis in a patient with plasminogen type I deficiency--case report with review of literature]
BACKGROUND: Ligneous conjunctivitis is a rare chronic pseudomembranous conjunctivitis. ... severe cases with generalised symptoms systemic therapy with lys-plasminogen is necessary ...
more hits from: http://www.medscape.com/medline/abstract/11987044 - 25 KB
Homozygous Mutations in the Plasminogen Gene of Two Unrelated Girls With Ligneous Conjunctivitis -- Schuster et al. ...
This Article. Services. PubMed. RAPID COMMUNICATION. Homozygous Mutations in the Plasminogen Gene of Two Unrelated Girls With Ligneous Conjunctivitis ... Ligneous conjunctivitis is a rare and ... Therapy with a Purified Plasminogen Concentrate in an Infant with Ligneous Conjunctivitis and Homozygous Plasminogen ...
more hits from: http://www.bloodjournal.org/cgi/content/abstract/90/3/958 - 37 KB
Homozygous Mutations in the Plasminogen Gene of Two Unrelated Girls With Ligneous Conjunctivitis -- Schuster et al. ...
This Article. Services. Google Scholar. PubMed. RAPID COMMUNICATION. Homozygous Mutations in the Plasminogen Gene of Two Unrelated Girls With Ligneous Conjunctivitis ... Ligneous conjunctivitis is a rare and ... Therapy with a Purified Plasminogen Concentrate in an Infant with Ligneous Conjunctivitis and Homozygous Plasminogen ...
more hits from: http://www.bloodjournal.org/cgi/lookup?vol=90&fp=958&view=abstract - 39 KB
LIGNEOUS CONJUNKTIVITIS IN SEVERE TYP I PLASMINOGEN DEFICIENCY
... case of an ligneous conjunctivitis after systemic application of plasminogen is to be seen ... intravenous application of plasminogen offers new possibilities in therapy, but a long ...
more hits from: http://www.dog.org/1999/e-abstract99/102.html - 3 KB
Plasminogen
... Reactant; Conjunctivitis, Ligneous; Fibrinogenolysis; Fibrinolysis; Tissue Plasminogen Activator ... therapy. Consider testing plasminogen in patients with ligneous conjunctivitis ...
more hits from: http://www.mgh.harvard.edu/labmed/lab/coag/handbook/co003700.htm - 27 KB
gms | | Ligneous conjunctivitis in a patient with plasminogen type I deficiency: case report
... Ligneous conjunctivitis in a patient with plasminogen type I deficiency: case ... patient developed a therapy resistant, chronic conjunctivitis after intraocular surgery (secondary ...
more hits from: http://www.egms.de/en/meetings/dog2004/04dog114.shtml - 11 KB
Result Page: 1 2 3 4 5 6 7 8 Next »
search within your results
(read full article)
Sources on the web: AlltheWeb
Related publications: AlltheWeb
Related documents to download: -
Notes: Search
Year: 2005
Title: Prenatal diagnosis in a family with severe type I plasminogen deficiency, ligneous conjunctivitis and congenital hydrocephalus
Date: - (dd/mm/yy) - 28/12/05
Authors: Volker Schuster, Silvia Seidenspinner, Clemens Müller, Andreas Rempen
Abstract: Prenatal diagnosis in a family with severe
type I plasminogen deficiency, ligneous conjunctivitis
and congenital hydrocephalus Volker Schuster 1 *, Silvia Seidenspinner 1, Clemens Müller 2,
Andreas Rempen 3
1Children's Hospital, University of Würzburg,
Josef-Schneider-Strasse 2, 97080 Würzburg, Germany
2Department of Human Genetics, University of Würzburg,
Am Hubland, 97070 Würzburg, Germany
3Department of Gynaecology, University of Würzburg,
Josef-Schneider-Strasse 2, 97080 Würzburg, Germany
email: Volker Schuster (Schuster@mail.uni-wuerzburg.de)
*Correspondence to Volker Schuster, Children's Hospital, University of Würzburg, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
Funded by:
Deutsche Forschungsgemeinschaft; Grant Number: Schu 560/4-1
Keywords
type I plasminogen deficiency; ligneous conjunctivitis; autosomal-recessive inheritance; mutation; prenatal diagnosis
Abstract
Severe type I plasminogen deficiency may cause severe ligneous conjunctivitis,
a rare and unusual form of chronic pseudo-membranous conjunctivitis that usually starts in early infancy, but also pseudo-membranous lesions
of other mucous membranes in the mouth, nasopharynx,
trachea and female genital tract, and in rare cases congenital occlusive
hydrocephalus.
The index patient, the daughter of a consanguineous marriage, had suffered from severe ligneous conjunctivitis and had died from decompensated congenital hydrocephalus despite numerous shunt revisions. She was found to be homozygous for a non-sense mutation in exon 15 of the plasminogen gene (Trp597 Stop). In her next pregnancy, the mother asked for prenatal diagnosis of the plasminogen deficiency. Chorionic villus biopsy was performed at 12 weeks of gestation. DNA analysis of the plasminogen gene by PCR and single-strand conformation polymorphism (SSCP) revealed that the fetus exhibited an identical heterozygous band pattern as observed in the healthy mother. Therefore, the fetus was heterozygous for the Trp597 Stop mutation in plasminogen exon 15. In addition, the fetus was found to be male by cytogenetic analysis and by multiplex PCR analysis using two polymorphic X-chromosomal markers (DXS424, HPRT). These findings excluded the possibility of contamination by maternal DNA. It was concluded that the fetus was not at risk for ligneous conjunctivitis and its associated complications. After the birth of a healthy boy, plasminogen functional activity was shown to be 38 per cent. DNA analysis confirmed prenatal molecular genetic results. Copyright © 1999 John Wiley & Sons, Ltd.
--------------------------------------------------------------------------------
Received: 11 August 1998; Revised: 1 December 1998; Accepted: 15 December 1998
(read full article)
Sources on the web: Wilei InterScience
Related publications: Prenatal Diagnosis - Volume 19, Issue 5 , Pages 483 - 487
Wilei InterScience
Related documents to download: -
Notes:
Year: 1998
Title: Pulmonary involvement in a child with L.C.
Date: - (dd/mm/yy) - 27/12/05
Authors: Pediatric Pulmonology
Abstract: Tratto dal sito: http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd
Case Report
Pulmonary involvement in a child with ligneous conjunctivitis
and homozygous type I plasminogen deficiency
Pediatric Pulmonology
Volume 32, Issue 2 , Pages 179 - 183
Published Online: 24 Jul 2001
Copyright © 2001 Wiley-Liss, Inc.
Abstract
Ligneous conjunctivitis (LC) is a rare disorder characterized by a chronic course of recurrent
membranous lesions at conjunctivae. Pseudomembranes of other mucous membranes have
been reported in patients with LC, but to the best of our knowledge, no case with alveolar
involvement has been described. Here, we report a 2.5-year-old girl with LC who had tracheoaveolar
involvement and homozygous type I plasminogen deficiency. Tracheal involvement was diagnosed
by bronchoscopic biopsy and alveolar involvement with postmortem biopsy.
She was shown to be homozygous for frameshift mutation in plasminogen exon 14 (Gly565ins-G)
with molecular genetic examination of DNA which was obtained from parafin embedded postmortem lung tissue.
Ligneous inflammation of the upper and lower respiratory tract must be considered in children
with LC and recurrent respiratory tract problems.
Pediatr Pulmonol. 2001; 32:179-183. © 2001 Wiley-Liss, Inc.
--------------------------------------------------------------------------------
Received: 20 April 2000; Accepted: 30 April 2001
Tratto dal sito: http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd
(read full article)
Sources on the web: http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd
Related publications: Pediatric Pulmonology Volume 32, Issue 2 , Pages 179 - 183 Published Online: 24 Jul 2001 Copyright © 2001 Wiley-Liss, Inc.
Related documents to download:
Notes:
Year: 2001
Title: We report two unrelated Brazilian
Date: - (dd/mm/yy) - 27/12/05
Authors: Contarini* P., Araujo† P., Sousa‡ M. A. J., Oliveira§ M. H. C. F., Gadelha¶ T.
Abstract: Tratto dal sito: http://www.blackwellpublishing.com/isth2003/abstract.asp?id=9540
JOURNAL OF THROMBOSIS AND HAEMOSTASIS
Volume 1, Supplement 1, July 12-18 2003
Abstracts from XIX international ISTH Congress
Contarini* P., Araujo† P., Sousa‡ M. A. J., Oliveira§ M. H. C. F., Gadelha¶ T.
§Hemorio, Brazil; †Hospital Municipal da Piedade, Brazil; *Hospital Municipal Miguel Couto, Brazil;
‡Universidade Estadual do Rio de Janeiro, Brazil; ¶Universidade Federal do Rio de Janeiro, Brazil
We report two unrelated Brazilian patients who suffered from ligneous conjunctivitis (LC).
We describe the clinical course, histologic findings, coagulation studies and discuss the management
of these patients.
Patient 1 - V.H.R.M, 4 years and 9 months old, mulatto, male developed bilateral
conjunctivitis at the age of 2 years. The ophthalmologic examination showed thickened white-yellow
membranes on the tarsal conjunctivae of both eyes. He was treated with surgical excision followed
by topical corticosteroids with complete remission of the lesion in the right eye and repeated recurrence
in the left eye. Histopathologic examination of the pseudomembrane exhibited an inflammatory cellular infiltration,
granulation tissue and an extensive fibrin- leukocyte exudate. The functional activity of plasminogen
was 27% (normal range: 75–135%).
Patient 2 – B.F.S., 5 years old, white, female, was admitted
in our hospital at the age of 3 years, presenting conjunctivitis in the right eye with pseudomembranes.
She was treated with surgical excisions and topical corticosteroids, without success.
After the eighth surgical removal, she started therapy with local cyclosporine 2%, olopatadine,
fluorometholone, and heparin. The histology demonstrated eosinophilic material with amorphous aspect,
and acute and chronic inflammatory cells. The functional activity of plasminogen was 16%.
Ligneous conjunctivitis (LC) is a rare disease characterized by chronic recurrent membranous conjunctivitis,
caused by a type 1 plasminogen deficiency. It tends to occur in young children and is frequently associated
with similar lesions in other mucosal sites. Curative treatment of LC is not available.
This disorder has been treated with several topical medications (antibiotics, hyaluronidase, alpha-chymotrypsin,
heparin, corticosteroids, and cyclosporin) without success. Recently, systemic replacement therapy
with lys-plasminogen showed to be effective. However, the short half-life of the plasminogen and
the intravenous administration are limiting factors. The severity of the disease appears to be related
to the level of functional plasminogen activity. Both our cases resemble the heterozygous form of this deficiency
with the disease limited to ocular mucosa. In agreement with literature, we also observe that frequent
removals of the membranes are associated with a rapid recurrence.
To cite this abstract use the following format:
Journal of Thrombosis and Haemostasis 2003; 1 Supplement 1 July: abstract number
(read full article)
Sources on the web: www.blackwellpublishing.com
Related publications: www.blackwellpublishing.com
Related documents to download: -
Notes: -
Year: 2003
Title: Conjuntivitis lignea: a propósito de un caso
Date: - (dd/mm/yy) - 20/12/05
Authors: GIL HERNÁNDEZ MA, ABREU REYES P, MAESO FORTUNY C
Abstract: Tratto dal sito: http://www.oftalmo.com/sco/revista-14/14sco15.htm
ARCH. SOC. CANAR. OFTAL. 2003 - Nº 14 - CASO CLÍNICO INDICE
Conjuntivitis lignea: a propósito de un caso
Ligneous conjunctivitis. Case report
GIL HERNÁNDEZ MA, ABREU REYES P, MAESO FORTUNY C
RESUMEN
Presentamos los hallazgos oftalmológicos e histológicos de un paciente con una conjuntivitis
pseudomembranosa de curso crónico, que nos conducen hacia el diagnóstico
de conjuntivitis lignea o leñosa.
Palabras clave: Conjuntivitis lignea, pseudomembrana.
SUMMARY
We present the ophthalmoscopic and histologic findings of a patient with chronic pseudomebranous conjunctivitis,
these clinical findings led to the diagnosis of ligneous conjunctivitis.
Key words: Ligneous conjunctivitis, pseudomembrane.
--------------------------------------------------------------------------------
INTRODUCCIÓN
La conjuntivitis lignea o leñosa es una forma rara de conjuntivitis pseudomembranosa de curso crónico y recurrente.
Suele iniciarse en la infancia, presentando una afectación bilateral, pudiendo relacionarse con lesiones de otras
membranas mucosas en la boca, nasofaringe, traquea y vagina. A pesar de haber sido descrito inicialmente
con preferencia femenina, se han reportado casos de igualdad de la afección tanto en niños como en niñas (1).
La patogenia de la enfermedad se desconoce. Varios han sido los factores propuestos como inductores o
contribuyentes a su desarrollo, tales como infecciones bacterianas o víricas, traumatismos, defectos hereditarios
en el metabolismo conjuntival, aumento de la permeabilidad vascular, una reacción de hipersensibilidad
y una respuesta inflamatoria exagerada frente a una agresión del epitelio conjuntival (2).
Recientemente se ha relacionado con una deficiencia en el plasminógeno tipo I, lo que determina
una disminución de la fibrinolisis (3-6).
El tratamiento propuesto, ante el desconocimiento de su etiología, ha consistido en el uso tópico
de glucocorticoides, inmunosupresores tales como la ciclosporina al 2%, y un anticoagulante
como la heparina (7-9). Su asociación con un defecto en el plasminógeno ha determinado su uso como terapia,
tanto tópica como sistémica, en especial, en pacientes con patología ocular y sistémica (10-11).
CASO CLÍNICO
Varón de siete meses de edad que es llevado a urgencias por su madre presentando una conjuntivitis
que no responde al tratamiento antibioterápico convencional y con una evolución superior a las tres semanas.
En la exploración oftalmológica se aprecia hiperemia conjuntival con secreción mucosa y la presencia
de membranas blanco-amarillentas en la conjuntiva tarsal superior de ambos ojos e inferior en el ojo izquierdo (fig. 1).
Fig. 1: Aspecto de la pseudomembrana en la conjuntiva tarsal superior del ojo izquierdo.
Tras efectuar un frotis conjuntival no se aprecia crecimiento microbiano, por lo que se decide
asociar al tratamiento tópico un colirio glucocorticoide. Inicialmente la sintomatología mejora pero posteriormente
se aprecia un crecimiento de las membranas conjuntivales que adquieren un aspecto casi granulomatoso.
Se procede a la extirpación en quirófano de dichas membranas exofíticas siendo enviadas parte de ellas a
anatomía patológica y el resto a microbiología. El resultado demostró el no crecimiento microbiano
a pesar de su cultivo, y en el análisis histológico se aprecia la presencia de una reacción inflamatoria
aguda y crónica con depósito de material fibrohialino, sugestivo de conjuntivitis lignea (fig. 2) .
Fig. 2: Corte histológico, teñido con hematoxilina-eosina, de la pseudomembrana.
Apreciamos en el tejido subepitelial la presencia de fibrina, células inflamatorias agudas y crónicas,
y abundante material eosinófilo amorfo.
Ante dicho hallazgo se instaura tratamiento con colirio de dexametasona y colirio de ciclosporina al 2%,
asociando ambos durante un mes para luego disminuir de forma gradual el corticoide dejando la ciclosporina
tópica como único tratamiento.
Al revisar la bibliografía de este tipo de conjuntivitis y encontrar su asociación con un defecto
en el plasminógeno se efectúa hoja de interconsulta a hematología y se solicita al laboratorio reference
la determinación de la actividad del plasminógeno.
Siendo la dosis obtenida (<45%) inferior a la normal (75-150%).
En la actualidad tras tres meses de tratamiento el niño prosigue con tratamiento mediante ciclosporina
tópica y permanece sin la sintomatología inicial. En ningún caso ha presentado alteración o patología
que afecte a otras mucosas.
DISCUSIÓN
Los signos de la inflamación conjuntival dependen directamente de los cambios tisulares asociados
a la inflamación. En la conjuntiva se liberan sustancias vasoactivas y flogógenas que producen
vasodilatación, aumento de la permeabilidad vascular e infiltrado inflamatorio.
En la conjuntivitis lignea destaca, como característica principal, su cronicidad y la presencia
de lesiones pseudomembranosas, parecidas a leños, en la conjuntiva tarsal de forma bilateral.
La presencia de pseudomembranas en una conjuntivitis nos obliga a realizar diagnóstico
diferencial con aquellas conjuntivitis en donde es frecuente su presencia así, conjuntivitis virales
(herpes simplex, adenovirus), conjuntivitis bacterianas (neisseria meningitidis, stafilococus aureus,
streptococcus pyogenes, streptococcus pneumoniae, pseudomonas aeruginosa, escherichia coli),
conjuntivitis de inclusión del recién nacido (clamydia trachomatis), causticaciones, conjuntivitis leñosa,
penfigoide ocular y secundaria a la presencia de cuerpos extraños.
La exéresis de la pseudomembrana lleva con mucha frecuencia a la recidiva de las mismas,
en especial en la conjuntivitis leñosa (12). Estudios inmunohistoquímicos han demostrado la presencia
de una importante reacción inmune caracterizada por linfocitos T y una acumulación de células plasmáticas
y linfocitos B en la conjuntiva de estos pacientes, y mediante inmunofluorescencia se ha detectado
a la Ig G como componente fundamental del material hialino amorfo.
De ahí la buena respuesta que presentan estos pacientes ante el tratamiento
de forma tópica con corticoides y ciclosporina al 2% (13).
La demostración del defecto del plasminógeno en la conjuntivitis lignea determina que exista
una alteración en el sistema de fibrinolisis, con un depósito masivo de fibrina en el espacio extravascular
de las membranas mucosas. A pesar de esto no se ha demostrado tendencias trombóticas
en estos pacientes y, en casos severos, se aboga por emplear como tratamiento plasminógeno
tanto por vía tópica como sistémica.
En la actualidad nuestro paciente no presenta sintomatología sistémica y se encuentra
bien controlado con la ciclosporina tópica.
BIBLIOGRAFÍA
Bateman J, Pettit TH, Isenberg SJ, Simons K. B. Ligneous conjunctivitis.
An autosomal recessive disorder. J Pediatr Ophthalmol Strabismus 1986; 23: 137.
Hidayat A, Riddle P. Ligneous Conjunctivitis. A clinico-pathologic study of 17 cases.
Ophthalmology 1987; (94): 949-959.
Mingers AM, Heimburger N, Zeitler P, Pret HW, Schuster V. Homozygous type I plasminogen deficiency.
Semin Thromb Hemost 1997; 23 (3): 259-269.
Drew AF, Kaufman AH, Kombrinck KW, Danton MJ, Daugherty CC, Degen JL, Buggle TH.
Ligneous conjunctivitis in plasminogen-deficient mice. Blood 1998; 91(5): 1616-1624.
Kraft J, Lieb W, Zeitler P, Schuster V. Ligneous conjunctivitis in a girl with severe
type I plasminogen deficiency. Graesfes Arch Clin Exp Ophthalmol 2000; 238(9): 797-800.
Chen S, Wishart M, Hiscott P. Ligneous conjunctivitis: a local manifestation of a systemic disorder?
J AAPOS 2000; 4 (5): 313-315.
Holland EJ, Olsen TW, Ketcham JM, Florine C, Krachmer JH, Purcell JJ, Tessler HH, Sugar J.
Topical ciclosporin A in the treatment of anterior segment inflammatory disease. Cornea 1993; 12 (5): 413-419.
De Cock R, Ficker LA, Dart JG, Garner A, Wright P.
Topical heparin in the treatment of ligneous conjunctivitis. Ophthalmology 1995; 102 (11): 1654-1659.
Lecame M, Conan S, Le Jeune V, Marie Dit Dinard B, Piriou G, Colin J, Borgnis-Desbordes N.
Treating a ligneous conjunctivitis with false membrane through a local tri-therapy:
a glucocorticoid, an anticoagulant and an immunosuppressor. Journal de Pharmacie Clinique 2001; 20: 25-27.
Schott D, Dempfle CE, Beck P, Liermann A, Mohr-Pennert A, Goldner M, Mehlem P, Azuma H, Shuster V,
Mingers AM, Shawars HP, Kramer MD. Therapy with purified plasminogen concentrate in an infant
with ligneous conjunctivitis and homozygous plasminogen deficiency. N Engl J Med 1998; 339 (23): 1679-1686.
Watts P, Suresh P, Mezer E, Ells A, Albosetti M, Bajzar L, Marzinotto V, Andrew M, Massicotle P, Rootman D.
Effective treatment of ligneous conjunctivitis with topical plasminogen. Am. J. Ophthalmol 2002; 134(2): 310.
Hidayat AA, Riddle PJ. Ligneous conjunctivitis. Ophthalmology 1987; 94: 949-954.
Holland EJ, Chan CC, Kuwabara T et al. Inmunohistologic findings and results
of treatment with ciclosporine in ligneous conjunctivitis. Am J Ophthalmol 1989; 107: 160-166.
(read full article)
Sources on the web: www.oftalmo.com
Related publications: ARCH. SOC. CANAR. OFTAL. 2003 - Nº 14 - CASO CLÍNICO INDICE
Related documents to download: -
Notes: >> Tratto dal sito:
Year: 2003
Title: Ligneous conjunctivitis: a case report.
Date: - (dd/mm/yy) - 20/12/05
Authors: Shimabukuro M, Iwasaki N, Nagae Y, Nakagawa Y, Ohtori Y, Inoue Y, Tano Y. Department of Ophthalmology, Osaka University Medical School, Osaka, Japan
Abstract:
>>>>>drawn by the site: NCBI (National Library of Medicine)
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11485769&query_hl=5
MEDLINE, NCBI, National Center for Biotechnology; Information, National Library of Medicine, NLM, PubMed
PubMed is the National Library of Medicine's
Jpn J Ophthalmol. 2001 Jul-Aug;45(4):375-7.
>>>>drawn by the site: ScienceDirect - Japanese Journal of Ophthalmology :
Ligneous Conjunctivitis: A Case Report
Japanese Journal of Ophthalmology - Volume 45, Issue 4 , July-August 2001, Pages 375-377
doi:10.1016/S0021-5155(01)00342-2
Copyright © 2001 Japanese Ophthalmological Society. Published by Elsevier Science Inc.
Clinical investigations
Ligneous Conjunctivitis
Department of Ophthalmology,
Osaka University Medical School, Osaka, Japan
Received 27 December 1999. Available online 6 August 2001.
============================================
Ligneous conjunctivitis: a case report.
Shimabukuro M, Iwasaki N, Nagae Y, Nakagawa Y, Ohtori Y, Inoue Y, Tano Y.
Department of Ophthalmology, Osaka University Medical School, Osaka, Japan.
BACKGROUND: Ligneous conjunctivitis is a rare condition characterized by chronic, recurrent conjunctivitis
associated with pseudomembrane, and it may involve other mucous membranes in the mouth, nasopharynx,
trachea, and vagina. We examined and treated a case of presumed ligneous conjunctivitis.
CASE: The patient was a 10-year-old boy. His chief complaints were visual impairment, discomfort,
and discharge, but no itching in his eyes. His upper eyelids appeared thick without swelling.
He had a past history of surgery for lid entropion. His two siblings had similar follicular conjunctivitis.
OBSERVATIONS: This case exhibited several characteristics of ligneous conjunctivitis, such as large follicles,
recurrent pseudomembrane and normal level IgE in the serum.
Indispensable characteristics of vernal keratoconjunctivitis, strong itching, and extensive papillary formation,
were not found. In spite of the lack of woody hardness of the conjunctiva, other clinical findings led to the
diagnosis of ligneous conjunctivitis. Definite histological diagnosis was not obtained, because of the lack
of common histological characteristics among previously reported cases with ligneous conjunctivitis.
The boy had developed corticosteroid glaucoma after instillation of dexamethasone 0.1%
for 7 months at a previous time. We successfully treated this case with combined instillation
of fluorometholon and cyclosporin after trabeculotomy.
CONCLUSIONS: Ligneous conjunctivitis must be considered as one type of differential diagnosis
of vernal keratoconjunctivitis.
Cyclosporin is an effective alternative for the treatment of ligneous conjunctivitis,
especially in a case with a possible history of corticosteroid glaucoma.
Correspondence and reprint requests to:
Mikiko SHIMABUKURO, MD, Department of Ophthalmology, Kansai Rousai Hospital,
3-1-69, Inabasou, Amagasaki-city, Hyogo 660-8511, Japan
>>> Full Text + Links
>>> PDF (167 K)
>>> E-mail Article
>>> Japanese Journal of Ophthalmology - Volume 45, Issue 4 , July-August 2001, Pages 375-377
(read full article)
Sources on the web: NCBI
Related publications: MEDLINE, NCBI, National Center for Biotechnology
Related documents to download: -
Notes:
Year: 1999
Title: TYPE I PLASMINOGEN DEFICIENCY AND L.C.
Date: - (dd/mm/yy) - 19/12/05
Authors: JP McCluskie, M Albisetti, D Rootman, M Andrew *, V Marzinotto, P Watts, L Bajzar*.
Abstract: Tratto dal sito: http://www.ccs.ca/society/congress2001/abstracts/abs/a156.htm
TYPE I PLASMINOGEN DEFICIENCY AND LIGNEOUS CONJUNCTIVITIS
156 - TYPE I PLASMINOGEN DEFICIENCY AND LIGNEOUS CONJUNCTIVITIS
JP McCluskie, M Albisetti, D Rootman, M Andrew *, V Marzinotto, P Watts, L Bajzar*.
Hamilton Civic Hospitals Research Centre, Hamilton, Ontario and The Hospital for Sick Children,
Toronto, Ontario, Canada - *Supported in part by Heart and Stroke Foundation of Ontario
Ligneous conjunctivitis (LC) is usually characterised by bilateral wood-like pseudomembranes,
composed primarily of fibrin, on the palpebral surface of the eye though other mucosal sites may be affected.
Onset of LC occurs in childhood. Furthermore, LC is likely due to decreased fibrinolysis, as it has been linked
to type I plasminogen (Pg) deficiency. SD, AN and CM are 3 children identified with LC.
Initially Pg concentrations were found to be within the normal range for both SD and CM using a streptokinase assay.
This finding was inconsistent with the established link between LC and Pg deficiency.
Therefore, a clot lysis assay, utilizing fibrin as a physiologic plasmin (Pn) substrate, was used to assess
the concentration of Pg in patient plasmas. tPA did not induce fibrinolysis of clots formed from patient plasma,
even when 2 nM tPA was used; normally 0.25 nM tPA induced lysis within 60 min.
However, tPA-mediated fibrinolysis was reconstituted in patient plasma supplemented with Pg.
Therefore, patient fibrin was both an effective tPA-Pg cofactor and Pn substrate; and the patients were likely Pg deficient.
Subsequently, Pg antigen concentration was determined for patient and parent plasmas:
SD 29 nM, FD 1.77 uM, MD 1.65 uM; AN 16 nM (FN & MN nd); CM 190 nM, FM 0.8 uM, MM 1.4 uM.
Although SD, AN and CM are type I Pg deficient, analysis of Western blots suggest that patient Pg is full length.
A case study for pharmacologic treatment of LC by intravenous infusion of 1000 CU Pg over 24 h has been reported.
This large amount of Pg prohibits long-term treatment therefore we assessed topical treatment with Pg eye drops.
SD, AN and CM were treated with 10 uM Pg in 0.15% hyaluronate for 23, 5, 18 weeks, respectively, without recurrence.
Together these results indicate that the streptokinase assay may yield false positive results and
that Pg eye drops may provide a viable and cost effective treatment for LC.
Since thrombotic tendencies have not been observed in these individuals these patients could provide
a wealth of information regarding the physiologic role of Pg.
DNC
NEXT
(read full article)
Sources on the web: Congress 2001
Related publications: www.ccs.ca : Congress 2001
Related documents to download: -
Notes:
Year: 2001
|
