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PubMed1995

The role of fibrinogen D domain intermolecular association sites in the polymerization of fibrin and fibrinogen Tokyo II (gamma 275 Arg-->Cys).

Intermolecular end-to-middle domain pairing between a thrombin-exposed 'A' polymerization site in the central 'E' domain of fibrin, and a constitutive complementary 'a' site in each outer 'D' domain ('D:E'), is necessary but not alone sufficient for normal fibrin assembly, as judged from previous studies of a congenital dysfibrinogen, Tokyo II (gamma 275 arg-->cys), which showed defective fibrin clot assembly and a normal D:E interaction (Matsuda, M., M. Baba, K. Morimoto, and C. Nakamikawa, 1983. J. Clin. Invest. 72:1034-1041). In addition to the 'a' polymerization site, two other constitutive intermolecular association sites on fibrinogen D domains have been defined: between gamma chain regions containing the carboxy-terminal factor XIIIa crosslinking site ('gamma XL:gamma XL'); and between sites located at the outer ends of each molecule ('D:D') (Mosesson, M. W., K. R. Siebenlist, J. F. Hainfeld, and J. S. Wall, manuscript submitted for publication). We evaluated the function of these sites in Tokyo II fibrinogen, and confirmed that there was a normal fibrin D:E interaction, as determined from a normal fibrin crosslinking rate in the presence of factor XIIIa. We also found a normal gamma XL: gamma XL interaction, as assessed by a normal fibrinogen crosslinking rate. Judging from electron microscopic images, factor XIIIa-crosslinked Tokyo II fibrinogen failed to form elongated double-stranded fibrils like normal fibrinogen. Instead, it formed aggregated disordered collections of molecules, with occasional short fibrillar segments. In addition, Tokyo II fibrin formed an abnormal, extensively branched clot network containing many tapered terminating fibers. These findings indicate that the Tokyo II fibrinogen defect results in a functionally abnormal D:D self-association site, and that a normal D:D site interaction is required, in addition to D:E, for normal fibrin or fibrinogen assembly.

Binding Sites↗
PubMed2005

Fibrinogen Philadelphia, a hypodysfibrinogenemia characterized by abnormal polymerization and fibrinogen hypercatabolism due to gamma S378P mutation.

Fibrinogen Philadelphia, a hypodysfibrinogenemia described in a family with a history of bleeding, is characterized by prolonged thrombin time, abnormal fibrin polymerization, and increased catabolism of the abnormal fibrinogen. Turbidity studies of polymerization of purified fibrinogen under different ionic conditions reveal a reduced lag period and lower final turbidity, indicating more rapid initial polymerization and impaired lateral aggregation. Consistent with this, scanning and transmission electron microscopy show fibers with substantially lower average fiber diameters. DNA sequence analysis of the fibrinogen genes A, B, and G revealed a T>C transition in exon 9 resulting in a serine-to-proline substitution near the gamma chain C-terminus (S378P). The S378P mutation is associated with fibrinogen Philadelphia in this kindred and was not found in 10 controls. This region of the gamma chain is involved in fibrin polymerization, supporting this as the polymerization defect causing the mutation. Thus, this abnormal fibrinogen is characterized by 2 unique features: (1) abnormal polymerization probably due to a major defect in lateral aggregation and (2) hypercatabolism of the mutant protein. The location, nature, and unusual characteristics of this mutation may add to our understanding of fibrinogen protein interactions necessary for normal catabolism and fibrin formation.

Afibrinogenemia↗
PubMedDate not supplied

The role of the RGD peptides and the gamma chain peptide of fibrinogen on fibrinogen binding to activated platelets.

The interaction of fibrinogen with platelet membrane glycoprotein (GP) IIb/IIIa complex is inhibited by the RGD peptides and the peptides corresponding to a sequence unique to fibrinogen in the carboxyl-terminal domain of the gamma chain. The present study was designed to examine the effects of these synthetic peptides on fibrinogen binding to thrombin-activated platelets. The order of potency of these peptides was as follows: RGDS = RGDF > GQQHHLGGAKQAGDV (G15). The RGES peptide had no inhibitory activity. The inhibitory effects of the peptides were synergistic when fibrinogen binding was measured in the mixture of the RGD peptide and the gamma chain peptide. By contrast, the inhibitory effect was additive when the binding was measured in the presence of the RGDS peptide and the RGDF peptide. Thrombin-induced platelet aggregation was also inhibited by these synthetic peptides. The order of potency was the same as that of the inhibition binding assay. These results provide evidence that the RGD sequences present at two different sites in the alpha chain and the gamma chain sequence inhibit fibrinogen binding to the GPIIb/IIIa complex, are mutually exclusive, and are in close spatial proximity in the folded molecule. We conclude that the presence of the RGD sequence and the gamma chain sequence involved in fibrinogen binding domains increases the affinity of fibrinogen to activated platelets.

Amino Acid Sequence↗
PubMed1986

Separation of human plasma fibrin stabilizing factor (factor XIII) from fibrinogen by fibrinogen polymer formation.

Human plasma fibrin stabilizing factor (factor XIII) may be separated from fibrinogen through reversible fibrinogen polymer formation at pH 6.6, gamma/2 0.3, 0 degrees C, and subsequent Bio-Gel A 1.5m filtration. Factor XIII activity is eluted after the monomer fibrinogen peak. Polymer fractions from eight preparations, processed in duplicate, contain a mean 0.002 units factor XIII per mg fibrinogen, or about 0.7% the factor XIII content of standard plasma. Factor XIII-free fibrinogen polymers are easily dissociated (greater than 98%) to the monomer form by incubation at 37 degrees C, 18 hours. The fibrinogen preparations utilized were devoid of plasma fibronectin; thus these studies also show that reversible human fibrinogen polymer formation occurs in its absence.

Chromatography, Gel↗
PubMed2003

Fibrinogen Magdeburg I: a novel variant of human fibrinogen with an amino acid exchange in the fibrinopeptide A (Aalpha 9, Leu-->Pro).

INTRODUCTION: The exchange of Aalpha 16, Arg for Cys or His is the most common molecular defect in dysfibrinogenemia directly affecting the thrombin cleavage site involved in fibrinopeptide A (FPA) release. Other amino acid exchanges within the fibrinopeptide A have been only rarely reported. MATERIALS AND METHODS: In clinically asymptomatic dysfibrinogenemic patients with low functional plasma fibrinogen (Fg) levels and prolonged thrombin time but normal or slightly prolonged batroxobin (reptilase) time, mutation analysis was carried out by direct sequencing of the coding regions of the three fibrinogen genes. Isolated fibrinogen was functionally characterized for thrombin- or batroxobin-induced fibrinopeptide release and fibrin formation. Fibrinogen and fibrinopeptides were structurally studied by electrophoretic techniques or high-performance liquid chromatography. RESULTS AND CONCLUSIONS: Molecular analysis revealed heterozygosity for a novel missense mutation T1182C in the FGA gene causing the amino acid exchange Aalpha 9, Leu-->Pro. Fibrin generation induced by thrombin was moderately impaired, whereas batroxobin-induced fibrin formation was almost normal. Release of the abnormal fibrinopeptide A by thrombin was delayed but fibrin monomer aggregation was almost normal. Cleavage of Aalpha chains by batroxobin was only slightly delayed. Fibrinopeptides A of the patient fibrinogen did not show any gross abnormality in chromatographic behaviour. This new molecular variant designated fibrinogen Magdeburg I supports the view that amino acid residue Leu-9 in the Aalpha chain as part of a small hydrophobic cluster is involved in the interaction with an apolar binding site of thrombin, thus adding to our understanding of the thrombin-fibrinogen interaction crucial in coagulation.

Child, Preschool↗
PubMed1987

Role of genetic variation at the fibrinogen locus in determination of plasma fibrinogen concentrations.

Three restriction fragment length polymorphisms (RFLPs) of the fibrinogen genes were used in 91 individuals to investigate the role of genetic variation at this locus in the determination of plasma fibrinogen. The strongest association was with a polymorphism detected with the beta-fibrinogen probe and the enzyme BclI. The probe detects two alleles, designated B1 and B2. The individuals with the genotype B1B1 had a mean fibrinogen of 2.74 g/l; those with B2B2 had a mean fibrinogen of 3.69 g/l (a level previously associated with a strongly increased risk of ischaemic heart disease); and those heterozygous for the two alleles, with the genotype B1B2, had a mean of 2.98 g/l. Genetic variation at the fibrinogen gene locus accounted for 15% of the total phenotypic variance in fibrinogen.

Female↗
PubMed2001

Variables associated with fibrinogen in a population-based study: interaction between smoking and age on fibrinogen concentration.

The aim of the study was to assess the association between fibrinogen and other cardiovascular risk factors. A cross-sectional population-based study in Gerona (Spain) was designed, 1544 subjects (747 men, 797 women) participated. Anthropometric measurements, blood pressure and blood samples were obtained. Fibrinogen was measured by a coagulometric method. Smoking habits, alcohol consumption and physical activity practice were recorded by questionnaires. Fibrinogen was directly related to age, body mass index (BMI) and female gender and inversely to alcohol and moderate-heavy physical activity practice. Fibrinogen was also higher in men and young women who smoked. In the multivariate analysis, age (regression coefficient (RC): 1.33; standard error (SE): 0.13; unit = 1 year), female gender (RC: 12.24; SE: 3.56) and BMI (RC: 1.83; SE: 0.39; unit = 1 kg/m2) were directly associated with fibrinogen, whereas alcohol (RC: -0.04; SE: 0.01; unit = 1 g/d) was inversely associated. A statistically significant interaction between smoking and age was observed. Age was the strongest variable associated with fibrinogen and modifies the association between smoking and fibrinogen; the magnitude of this association increases with age.

Adult↗
PubMed2002

The G-455A polymorphism of the fibrinogen Bbeta-gene relates to plasma fibrinogen in male cases, but does not interact with environmental factors in causing myocardial infarction in either men or women.

OBJECTIVES: To elucidate the association between a genetic polymorphism of the fibrinogen Bbeta-gene (G-455A) and plasma fibrinogen levels and myocardial infarction (MI), respectively. In addition, to explore potential synergistic gene-environment interactions involving this polymorphism--until now, these data were unavailable. DESIGN SETTING AND SUBJECTS: This case-referent study of subjects aged 45-70 and living in Stockholm includes 834 men and 346 women with first-time MI and 1034 men and 494 women randomly chosen as referents from the population. The cases were identified between 1992 and 1994 at the 10 emergency hospitals in Stockholm County. MAIN OUTCOME MEASURES: MI and plasma fibrinogen levels. RESULTS: Crude analyses associated a high level of plasma fibrinogen with an increased risk of MI in both men and women. However, the relative risk decreased after controlling for other risk factors. The multivariate-adjusted odds ratio (OR) (95% confidence interval) was 1.6 (1.2-2.3) for men and 1.5 (0.9-2.6) for women. Presence of the A allele at the G-455A polymorphic site indicated higher plasma fibrinogen levels than the presence of the G allele, but the difference was only statistically significant for male cases. The -455A allele was not associated with an increased risk of MI. Furthermore, there were no strong indications of synergistic interaction between the G-455A polymorphism and any of the environmental exposures considered. CONCLUSIONS: In this large number of MI cases and referents, a high level of plasma fibrinogen was independently associated with increased risk of MI in men but not in women. The presence of the A allele at the G-455A polymorphism of the fibrinogen Bbeta-gene was not associated with increased risk of MI, and no synergistic gene-environment interactions were detected.

Age Factors↗
PubMed1999

Relations of plasma fibrinogen level in children to measures of obesity, the (G-455-->A) mutation in the beta-fibrinogen promoter gene, and family history of ischemic heart disease: the Columbia University BioMarkers Study.

Higher plasma fibrinogen levels are associated with increased risk of myocardial infarction in adults, but little is known about factors that influence fibrinogen levels in childhood. The authors examined the associations of measures of obesity, presence of the (G-455-->A) allele in the beta-fibrinogen promoter gene, and family history of early onset of ischemic heart disease with plasma fibrinogen levels in children. Children (n = 299) were recruited during 1994-1997 from 276 families living in a racially mixed area of New York City. The mean age of the study children was 9.9 years; 79% were Hispanic. The frequency of the (G-455-->A) allele was lower in Hispanics than in non-Hispanic Whites (15.5% vs. 28.3% in children (p < 0.01) and 13.9% vs. 28.3% in parents (p < 0.001)). Graded relations of children's plasma fibrinogen levels were found with tertiles of body mass index (weight (kg)/height (m)2) and sum of skinfolds (tests for linear trend: p < 0.001). Plasma fibrinogen levels in the children were not related to race/ethnicity, presence of the (G-455-->A) allele, or family history. Multiple linear regression analyses adjusting plasma fibrinogen levels for age, sex, race/ethnicity, the (G-455-->A) allele, and family history of early onset of heart disease showed a significant association with either body mass index or sum of skinfolds (p < 0.001 for both models) but not with the other variables.

Adolescent↗
PubMed1989

DNA polymorphisms at fibrinogen loci and plasma fibrinogen concentration.

Associations have been reported between restriction fragment length polymorphisms (RFLPs) at fibrinogen loci and plasma fibrinogen concentration, in a British study. We have examined a series of unrelated Norwegians. We found no association between plasma fibrinogen concentration and any genotype in either of two fibrinogen polymorphisms examined (one at the alpha-fibrinogen locus, the other at the beta-fibrinogen locus). We have also examined monozygotic twins and evaluated heritability of fibrinogen level by the intraclass correlation coefficient. We arrived at an unimpressive estimate of heritability. With such a low level of heritability, it would have been surprising if we had found an association with a single gene marker in a relatively limited series of people. The reason for the discrepancy between the British and the Norwegian study is unknown. Great care has to be exercised in interpreting disease associations, since with DNA variations being examined at an increasing number of "candidate loci", the risk of finding spurious associations increases with the number of analyses conducted.

Adult↗
PubMed1987

The effect of thrombomodulin on the cleavage of fibrinogen and fibrinogen fragments by thrombin.

Thrombomodulin acts as a linear competitive inhibitor of thrombin with respect to the substrate fibrinogen. In the present study the effect of thrombomodulin on the activity of thrombin with fragments of the A alpha and B beta chain of fibrinogen has been examined. The cleavage of fibrinopeptide A from the N-terminal disulphide knot, fragment 1-44 and fragment 1-51 of the A alpha chain was inhibited by thrombomodulin. The average value for the inhibition constant obtained with these substrates was 0.83 +/- 0.09 nM, which was in good agreement with the values obtained previously for the inhibition of thrombin by thrombomodulin with native fibrinogen as the substrate [Hofsteenge, J., Taguchi, H. & Stone, S. R. (1986) Biochem. J. 237, 243-251]. In contrast, the cleavage of fibrinopeptide A from fragment 1-23 and fragment 1-29 of the A alpha chain was not affected by thrombomodulin. Although the cleavage of the B beta chain in the intact fibrinogen molecule was inhibited by thrombomodulin [Hofsteenge, J., Taguchi, H. & Stone, S. R. (1986) Biochem. J. 237, 243-251], the release of fibrinopeptide B from the N-terminal disulphide knot and the N-terminal 118-residue fragment of the B beta chain was not inhibited by thrombomodulin. In addition, we determined the second-order rate constants of cleavage of these substrates using human thrombin. Fragments of the A alpha chain whose cleavage was inhibited by thrombomodulin were found to have values for kcat/Km that were within one order of magnitude of that for the native fibrinogen, whereas those for A alpha chain fragments whose cleavage was not inhibited by thrombomodulin were found to be more than two orders of magnitudes lower. From these results we conclude that only a relatively small portion of the A alpha chain of the fibrinogen molecule is responsible for the specific binding to thrombin that is affected by thrombomodulin. Moreover, residues 30-44 of the A alpha chain play an important role in this thrombin-fibrinogen interaction.

Animals↗
PubMed2004

Plasma fibrinogen concentration predicts the risk of myocardial infarction differently in various parts of Europe: effects of beta-fibrinogen genotype and environmental factors. The HIFMECH Study.

The propensity to atherothrombotic disease differs in Europe, with high-risk regions located in the North of Europe and lowrisk regions in the South of Europe. The HIFMECH study (Hypercoagulability and Impaired Fibrinolytic function MECHanisms predisposing to myocardial infarction (MI) study) was undertaken to elucidate genetic and environmental mechanisms underlying MI based on investigations of postinfarction patients and healthy individuals recruited from Stockholm, Sweden, London, England (North of Europe), Marseille, France and San Giovanni Rotondo, Italy (South of Europe). In the present report, emphasis was placed on fibrinogen, a multifunctional protein, widely recognized as an independent predictor of atherothrombotic disease. The adjusted plasma fibrinogen concentration was an independent discriminator between cases and controls in London (SOR 3.58; 95% CI 1.31; 9.83), but not in the other centres. Genotyping for six beta-fibrinogen promoter single nucleotide polymorphisms was performed of which -249C/T, -455G/A and -854G/A were used in analysis as a consequence of the linkage disequilibrium pattern. Four haplotypes, with similar distribution across Europe, were detected: CGG (46.7%), CAG (20.3%), TGG (18.2%) and CGA (14.8%). A significant haplotype effect on plasma fibrinogen concentration was observed in patients (p < 0.001) but not in controls (p = 0.08). The -455G/A genotype related to plasma fibrinogen concentration amongst patients along with centre and IL-6 concentration (together explaining 11.5% of the variation), whereas predictors amongst controls included centre, body mass index, IL-6 and smoking habit (explaining 15.7%). Thus, plasma fibrinogen concentration contributes differently to MI across Europe, and a disease-related stimulus is required to evoke allele-specific regulation of fibrinogen synthesis.

Aged↗
PubMed2006

Epistatic and pleiotropic effects of polymorphisms in the fibrinogen and coagulation factor XIII genes on plasma fibrinogen concentration, fibrin gel structure and risk of myocardial infarction.

An intricate interplay between the genes encoding fibrinogen gamma (FGG), alpha (FGA) and beta (FGB), coagulation factor XIII (F13A1) and interleukin 6 (IL6) and environmental factors is likely to influence plasma fibrinogen concentration, fibrin clot structure and risk of myocardial infarction (MI). In the present study, the potential contribution of SNPs harboured in the fibrinogen, IL6 and F13A1 genes to these biochemical and clinical phenotypes was examined. A database and biobank based on 387 survivors of a first MI and population-based controls were used. Sixty controls were selected according to FGG 9340T > C [rs1049636] genotype for studies on fibrin clot structure using the liquid permeation method. The multifactor dimensionality reduction method was used for interaction analyses. We here report that the FGA 2224G > A [rs2070011] SNP (9.2%), plasma fibrinogen concentration (13.1%) and age (8.1%) appeared as independent determinants of fibrin gel porosity. The FGA 2224G > A SNP modulated the relation between plasma fibrinogen concentration and fibrin clot porosity. The FGG-FGA*4 haplotype, composed of the minor FGG 9340C and FGA 2224A alleles, had similar effects, supporting its reported protective role in relation to MI. Significant epistasis on plasma fibrinogen concentration was detected between the FGA 2224G > A and F13A1 Val34Leu [rs5985] SNPs (p < 0.001). The FGG 9340T > C and FGB 1038G > A [rs1800791] SNPs appeared to interact on MI risk, explaining the association of FGG-FGB haplotypes with MI in the absence of effects of individual SNPs. Thus, epistatic and pleiotropic effects of polymorphisms contribute to the variation in plasma fibrinogen concentration, fibrin clot structure and risk of MI.

Environment↗
PubMed1993

Sialic acid in fibrinogen: effects of sialic acid on fibrinogen-fibrin conversion by thrombin and properties of asialofibrin clot.

The final stage in a series of blood coagulating reactions is fibrinogen-fibrin conversion by thrombin. This reaction consists of fibrinopeptide A and fibrinopeptide B release, polymerization of fibrin monomer, and stabilized fibrin formation by factor XIII. The latter two reactions require calcium. In the present study there was no difference in the rate of thrombin-induced fibrinopeptide release between fibrinogen and asialofibrinogen where sialic acid in the terminal end of carbohydrate moiety of fibrinogen was removed by neuraminidase, but turbidity associated with asialofibrin clot formation was increased more rapidly. In asialo-derivatives, the dissolution time of the clots in high concentrated urea solution tended to be shortened and rigidity as a gel tended to be decreased. In measurement by thromboelastography there was no difference in the reaction time (r) between fibrinogen and asialofibrinogen, but the maximum amplitude (ma) was obviously decreased in asialofibrinogen. Furthermore, when the rate of cross-link formation between gamma chains by F-XIII was compared, the production of gamma-dimer in the same reaction time was found to be lower and formation of stabilized fibrin tended to be retarded in asialofibrinogen. Sialic acid in fibrinogen thus may clearly influence the polymerization of fibrin-monomer and the formation of cross-linked fibrin in a series of reactions for fibrinogen-fibrin conversion. This may be consistent with the theory that fibrinogen sialic acid residues are low affinity calcium-binding sites and influence fibrin assembly.

Asialoglycoproteins↗
PubMed1991

The peptide Glu-His-Ile-Pro-Ala binds fibrinogen and inhibits platelet aggregation and adhesion to fibrinogen and vitronectin.

Antiplatelet agents are clinically useful as antithrombotic entities. The importance of antiplatelet agents led us to design, synthesize, and characterize a new antiplatelet peptide. This peptide is a presumptive mimic of a ligand binding site on the platelet fibrinogen receptor. Unlike peptides related to Arg-Gly-Asp-Ser and His-His-Leu-Gly-Gly-Ala-Lys-Gln-Ala-Gly-Asp-Val that bind to the fibrinogen receptor, this peptide binds to fibrinogen. The anticomplementarity hypothesis was used to design this presumptive peptide mimic of the vitronectin binding site on the fibrinogen receptor, glycoprotein IIb/IIIa complexes. The resulting peptide (Glu-His-Ile-Pro-Ala) has the characteristics of a fibrinogen binding site mimic: It binds fibrinogen and inhibits both the adhesion of platelets to fibrinogen and platelet aggregation. The peptide also inhibits the adhesion of platelets to vitronectin. The antiplatelet activity of this mimic peptide was dependent on its amino acid sequence, since closely related analogues were either inactive or less active inhibitors of platelet function than the original peptide. These results demonstrate that the peptide Glu-His-Ile-Pro-Ala has the characteristics expected of a mimic of a glycoprotein IIb/IIIa ligand binding site.

Adenosine Diphosphate↗
PubMed2003

New molecular defects in the gamma subdomain of fibrinogen D-domain in four cases of (hypo)dysfibrinogenemia: fibrinogen variants Hannover VI, Homburg VII, Stuttgart and Suhl.

Four new molecular abnormalities in the gamma subdomain of the D domain elucidated in three unrelated thrombophilic patients and in one asymptomatic case of hypofibrinogenemia are reported: fibrinogen Suhl, gamma 326, Cys-->Tyr, fibrinogen Hannover VI, gamma 336 Met-->Ile, fibrinogen Stuttgart, gamma 345, Asn-->Asp and fibrinogen Homburg VII, gamma 354,Tyr-->Cys. In all cases, fibrin polymerization in plasma is impaired. In the case of fibrinogen Suhl, there was a normalization of fibrin polymerization in plasma at higher Ca(2+) concentration. The protective effect of Ca(2+) on plasmic degradation of fibrinogen was incomplete with all three variants. The fibrinogen molecules in variants Homburg VII and Suhl contain covalently bound albumin. Fibrin clot structure was abnormal in case of variant Homburg VII, with finer and more branched fibers forming a less porous clot. Experimental data indicate possible effects of the molecular abnormalities on Ca(2+)-binding, D-E interaction and lateral association of protofibrils.

Adult↗
PubMed1992

Genetic variation at fibrinogen loci and plasma fibrinogen levels.

In view of the controversy regarding genetic variation at the fibrinogen loci and plasma fibrinogen levels, we have analysed DNA polymorphisms at the alpha (TaqI), beta (BclI and HaeIII), and gamma (KpnI/SacI) fibrinogen loci in 247 subjects whose plasma fibrinogen was determined by clotting and nephelometric assays. Strong linkage disequilibrium was found between the alpha/TaqI and gamma/KpnI/SacI markers and between the beta/BclI and beta/HaeIII markers. A lesser association was found between the alpha/TaqI and beta/BclI loci, beta/BclI and gamma/KpnI/SacI markers, alpha/TaqI and beta/HaeIII markers, and the gamma/KpnI/SacI and beta/HaeIII markers. This is consistent with the known physical order of these loci and suggests a relative excess of recombination in the alpha/gamma to beta interval. Plasma fibrinogen levels, by either assay method, when corrected or uncorrected for age, sex, and smoking habit, did not show any statistically significant associations with the four fibrinogen polymorphisms examined at the alpha, beta, and gamma fibrinogen loci either singly or when analysed as a haplotype.

Blotting, Southern↗
PubMed2005

[Fibrinogen substitution. Use in the treatment of bleeding due to lack of fibrinogen].

Fibrinogen is critically important in haemostasis. The concentration of fibrinogen in plasma is usually between 2 and 4 g/l (6-13 micromol/l). No detectable fibrinogen is found in afibrinogenaemia, a condition characterised by dramatic bleeding, while dys- and hypofibrinogenaemia have a lower-than-normal activity of functional fibrinogen. Acquired fibrinogen deficiency may occur with a variety of underlying pathologies. Fibrinogen substitution may be done with fresh-frozen plasma, cryoprecipitate and virally inactivated concentrates of fibrinogen.

Afibrinogenemia↗