fibrinopeptide-a and Blood-Coagulation-Disorders

In the guidelines for patients with acute coronary syndrome (ACS), reperfusion, antiplatelet treatment, completed with parenteral anticoagulant are the standard therapy. It is because ACS is the result of occlusion of related artery by thrombus compound mostly of platelets, with processes of aggregation and adhesion in its pathogenesis. However, many patients after ACS experience major adverse cardiovascular events (MACE) despite optimal long term antiplatelet therapy. The possible reasons seem to be not only the resistance to this drugs but also underestimated coagulation processes. This review describes the dysfunction of particular coagulation parameters in patients with coronary artery disease and their relationship with MACE after ACS.

Topics: Acute Coronary Syndrome; Anticoagulants; Antithrombins; Blood Coagulation Disorders; Fibrinogen; Fibrinopeptide A; Humans; Peptide Fragments; Platelet Aggregation Inhibitors; Protein Precursors; Prothrombin; Thromboplastin; von Willebrand Factor

Topics: Arachidonic Acids; beta-Thromboglobulin; Blood Coagulation Disorders; Blood Coagulation Tests; Blood Platelets; Complement Activation; Fibrin Fibrinogen Degradation Products; Fibrinopeptide A; Hemostasis; Humans; Platelet Factor 4; Radioimmunoassay

Through in depth studies, the biochemical pathways of hemostasis-related systems have been elucidated in terms of well-defined molecular mechanisms. The interrelationships of coagulation, fibrinolytic, kallikrein-kinin, platelets, prostaglandins, blood vessel, and complement systems are now well understood. Methods are currently developed to quantitate the molecular markers of each of these systems and define the involvement of each in disease and drug-related aberrations. Molecular markers allow for very early detection of disease states well before clinical manifestations are seen or current coagulation methods are affected. Therefore prophylactic or therapeutic treatment can begin before a disease state causes damage. Platelet factor 4 and beta-thromboglobulin are low molecular weight proteins released from the light (alpha) granules of platelets and provide a reliable index of endogenous activation and consumption of platelets. Serotonin and ADP are released during activation from the beta-granules and can be measured by high-performance liquid chromatography. Fibrinopeptide A is a molecular marker of the activation of the coagulation process and provides a useful index of the action of thrombin on fibrinogen. Elevated levels of this peptide are found in patients with hypercoagulable states or a thrombotic tendency. B beta 15-42 peptides are released at the early stages of fibrinolysis and are a useful collective parameter for the measurement of the activation of fibrinolysis. In both the primary and secondary fibrinolytic disorders this peptide is elevated. Circulating kinins provide information on the activation of the kallikrein system and are useful in monitoring coagulation and shock related disorders. Arachidonic acid metabolites, such as thromboxanes and prostacyclins, are products of platelet and vascular endothelium interactions. Their measurement in peripheral blood provides a useful tool to measure the vascular and platelet-related thrombotic defects. Furthermore, antiplatelet therapy can be monitored using these parameters. Numerous other metabolites of arachidonic acid such as the leukotrienes and PAFs also are generated in various immunopathologic disorders associated with hemostatic activation. Unlike the other coagulant tests, the measurement of molecular markers in native blood or plasma samples provides a true picture of the endogenous physiology. Since no activator or additive is added to influence the test, these markers provide th

Topics: Arachidonic Acid; Arachidonic Acids; beta-Thromboglobulin; Blood Coagulation Disorders; Blood Coagulation Tests; Fibrinolysis; Fibrinopeptide A; Humans; Kinins; Molecular Weight; Peptides; Platelet Factor 4; Prostaglandins

Recent advances in the elucidation of the molecular biochemistry of the coagulation proteins have provided the foundation for the development of synthetic substrates. These substrates are oligopeptide with either a chromophore or fluorophore group attached to the C-terminal end. They may be used in the laboratory to assay for a number of the serine proteases involved in either coagulation or fibrinolysis. Also, by suitably modifying the assay system, the various inhibitors can be quantitated. These substrates promise to revolutionize the coagulation laboratory allowing for more precise quantitation of trace enzymes and also improved standardization and precision of coagulation assays. In addition to these substrates, the introduction of a number of immunologic procedures into the diagnostic laboratory have been of major importance in elucidating the heterogeneity of hereditary coagulation defects. By correlating the immunologic assays, coagulation assays and clinical picture, a number of subgroups of hereditary deficiencies have been identified. Also, the immunologic assays have provided a means for identifying the carrier state of hemophilia A and have significantly contributed to the improved diagnosis of von Willebrand's disease. The use of ristocetin cofactor assays, when used in conjunction with the Factor VIII antigens, have enable the laboratory to more accurately diagnose the majority of patients with von Willebrand's disease. Ristocetin cofactor may be assayed utilizing either formalin fixed or washed platelets and recently a snake venom has been introduced to assay for this particular aspect of the Factor VIII complex. Platelet specific proteins (i.e., platelet factor 4 and beta-thromboglobulin) may be assayed utilizing either radioimmunoassays or in the case of platelet factor 4 modified coagulation assays. These proteins provide evidence of in vivo platelet activation and hopefully may, in the future, be correlated with platelet kinetics.

Topics: beta-Thromboglobulin; Blood Coagulation; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Platelets; Chromogenic Compounds; Factor IX; Factor VII; Factor VIII; Factor X; Fibrinogen; Fibrinopeptide A; Genetic Variation; Humans; Immunologic Techniques; Liver Diseases; Platelet Factor 4; Prothrombin

Topics: Angina Pectoris; Blood Coagulation Disorders; Blood Platelet Disorders; Coronary Disease; Coronary Vasospasm; Fibrinopeptide A; Humans; Myocardial Infarction; Prostaglandins; Thromboxanes

A large number of families have now been described in whom affected individuals have within their plasmas an abnormal species of fibrinogen (factor I). These defects, presumably examples of the phenomenon of allotypy--i.e., the synthesis of variant forms of a normal protein--have been inherited as autosomal dominant characteristics. In the great majority of cases, clotting is abnormally slow when thrombin is added to the abnormal plasma. Sometimes this defect appears to reside in impaired release of fibrinopeptides by thrombin. In other cases, fibrinopeptide release proceeds normally, but aggregation of fibrin monomers is impeded. In the latter instance, aggregation may be abnormally slow or, once it begins, it may proceed at a normal rate. Curiously, a bleeding tendency is more likely to occur in patients in whom fibrinopeptide release is impaired, while dehiscence of operative wounds rarely complicates dysfibrinogenemias associated with impaired aggregation of fibrin monomers; thrombosis has been described in both groups of patients. Most of the reported cases may be distinguished by functional criteria and by the physicochemical behavior and biochemical nature of the abnormal protein. Additonally, one family has been described in which plasma clots abnormally rapidly upon addition of thrombin, and two others in which crosslinking of fibrin by fibrin-stabilizing factor (factor XIII) is defective.

Topics: Afibrinogenemia; Amino Acid Sequence; Blood Coagulation Disorders; Child; Diagnosis, Differential; Female; Fibrinogen; Fibrinopeptide A; Fibrinopeptide B; Genes, Dominant; Humans; Male

The effect of bezafibrate (BZF) on plasma fibrinogen levels has been studied in 62 patients with atherosclerotic vasculopathy and hyperfibrinogenemia (643 +/- 15 (SEM) mg/dl). In a preliminary study, 15-30 days of BZF therapy (400-600 mg/day) normalized fibrinogen values in 16 subjects were compared to 16 controls. The effect was rapid and dose-dependent, and discontinuation in 6 patients who could not complete the study was followed by a rebound increase. A controlled study with 400 mg/day in the other 24 patients for 15 days showed that BZF lowered fibrinogen, PF4, blood filterability and platelet aggregating thresholds to the normal range. BTG and FpA decreased significantly compared to the placebo group (12 and 12 patients randomly distributed) without any variation in potentially biassing hematologic values (WBC, PLTS, Ht, lipids and plasma glucose). BZF may be of value in chronic treatment of hyperfibrinogenemia in atherosclerotic patients with a view to improving the haemorheologic pattern and, hence, reducing activation of the coagulation pathway.

Topics: Adult; Aged; Arteriosclerosis; Bezafibrate; Blood Coagulation Disorders; Blood Platelets; Fibrinogen; Fibrinopeptide A; Humans; Middle Aged; Platelet Aggregation; Random Allocation; Rheology

The effect of an immunotherapy with Corynebacterium parvum on the blood coagulation system was investigated in a randomized trial of 18 patients with metastatic breast cancer. All patients received cytostatic therapy. Additionally, C. parvum was given intravenously on day 15 of the cytostatic cycle (group I) or on day 1 (group II) or not at all (group III). Fibrinopeptide A increased within 2 h after intravenous administration of C. parvum in groups I and II and normalized after 24 h (p less than 0.05). Platelet counts decreased continuously in all treatment groups (p less than 0.05). Prothrombin time, fibrinolytic concentration, factor VIII:C and factor VIIIR:Ag were not affected. The fibrinolytic activity showed a slight but not statistically significant increase after intravenous administration of C. parvum. The data suggest that plasma hypercoagulability is induced or enhanced in man even after small intravenous doses of C. parvum.

Topics: Bacterial Vaccines; Blood Coagulation Disorders; Breast Neoplasms; Female; Fibrinopeptide A; Humans; Immunotherapy; Neoplasm Metastasis; Platelet Count; Propionibacterium acnes

In a patient who presented with a severe coagulation deficiency in plasma contrasting with a very mild hemorrhagic diathesis a homozygous Arg67His mutation was identified in the prothrombin gene. Wild-type (factor IIa [FIIa]-WT) and mutant Arg67His thrombin (FIIa-MT67) had similar amidolytic activity. By contrast, the k(cat)/K(m) value of fibrinopeptide A hydrolysis by FIIa-WT and FIIa-MT67 was equal to 2.1 x 10(7) M(-1)s(-1) and 9 x 10(5) M(-1)s(-1). Decreased activation of protein C (PC) correlated with the 33-fold decreased binding affinity for thrombomodulin (TM; K(d) = 65.3 nM vs 2.1 nM, in FIIa-MT67 and in FIIa-WT, respectively). In contrast, hydrolysis of PC in the absence of TM was normal. The Arg67His mutation had a dramatic effect on the cleavage of protease-activated G protein-coupled receptor 1 (PAR-1) 38-60 peptide (k(cat/)K(m) = 4 x 10(7) M(-1)s(-1) to 1.2 x 10(6) M(-1)s(-1)). FIIa-MT67 showed a weaker platelet activating capacity, attributed to a defective PAR-1 interaction, whereas the interaction with glycoprotein Ib was normal. A drastic decrease (up to 500-fold) of the second-order rate constant pertaining to heparin cofactor II (HCII) interaction, especially in the presence of dermatan sulfate, was found for the FIIa-MT67 compared with FIIa-WT, suggesting a severe impairment of thrombin inhibition by HCII in vivo. Finally, the Arg67His mutation was associated with a 5-fold decrease of prothrombin activation by the factor Xa-factor Va complex, perhaps through impairment of the prothrombin-factor Va interaction. These experiments show that the Arg67His substitution affects drastically both the procoagulant and the anticoagulant functions of thrombin as well as its inhibition by HCII. The mild hemorrhagic phenotype might be explained by abnormalities that ultimately counterbalance each other.

Topics: Arginine; Blood Coagulation Disorders; Cell Line; Consanguinity; Factor Va; Factor Xa; Female; Fibrinopeptide A; Hemorrhagic Disorders; Heparin Cofactor II; Histidine; Homozygote; Humans; Hydrolysis; Infant; Mutagenesis, Site-Directed; Mutation; Protein C; Prothrombin; Receptor, PAR-1; Receptors, Thrombin; Thrombin; Thrombomodulin; Thromboplastin; Transfection

Fibrinogen Milano XII was detected in an asymptomatic Italian woman, whose routine coagulation test results revealed a prolonged thrombin time. Fibrinogen levels in functional assays were considerably lower than levels in immunologic assays. Polymerization of purified fibrinogen was strongly impaired in the presence of calcium or ethylenediaminetetraacetic acid (EDTA). Two heterozygous structural defects were detected by DNA analysis: Aalpha R16C and gamma G165R. As seen previously with other heterozygous Aalpha R16C variants, thrombin-catalyzed release of fibrinopeptide A was 50% of normal. Additionally, the release of fibrinopeptide B was delayed. Immunoblotting analysis with antibodies to human serum albumin indicated that albumin is bound to Aalpha 16 C. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of plasmin digests of fibrinogen Milano XII in the presence of calcium or EDTA showed both normal and novel D1 and D3 fragments. Further digestion of abnormal D3 fragments by chymotrypsin resulted in degradation products of the same size as the fragments derived from normal fibrinogen. SDS-PAGE analysis under reducing conditions showed no difference between normal fibrinogen and fibrinogen Milano XII or between their plasmic fragments. Circular dichroism analysis revealed a shift in the mean residual ellipticity and a significant reduction of the alpha-helix content in the variant D3 fragment. It is concluded that the Aalpha-chain substitution is mainly responsible for the coagulation abnormalities, whereas the substitution in the gamma-chain induced a conformational change in the D3 fragment.

Topics: Aged; Blood Coagulation Disorders; Calcium; Chymotrypsin; Circular Dichroism; DNA; Edetic Acid; Electrophoresis, Polyacrylamide Gel; Female; Fibrinogen; Fibrinogens, Abnormal; Fibrinolysin; Fibrinopeptide A; Fibrinopeptide B; Heterozygote; Humans; Immunoblotting; Kinetics; Mutation; Peptide Fragments; Protein Conformation; Sequence Analysis, DNA; Serum Albumin; Thrombin; Thrombin Time

To test the hypothesis that the coagulation system and platelets are activated in sepsis, the uncomplicated and usually earliest stage of the septic process, and to compare the findings detected in sepsis with those found in severe sepsis and septic shock.. Prospective study comparing patients with sepsis, severe sepsis, and septic shock, and healthy volunteers.. General intensive care unit in a tertiary university hospital.. Seventy-four consecutive septic patients (45 with sepsis, 15 with severe sepsis, and 14 with septic shock). Fourteen healthy volunteers served as control subjects.. None.. After blood sampling, molecular activation markers of coagulation (prothrombin fragments 1 and 2, fibrinopeptide A, thrombin-antithrombin complexes, and monomers of fibrin) and of platelets (beta-thromboglobulin and platelet factor 4), several coagulation factors, global tests of coagulation (prothrombin time and activated partial thromboplastin time), and platelet count (PTL) were measured. In sepsis, prothrombin fragments 1 and 2, fibrinopeptide A, thrombin-antithrombin complexes, and monomers of fibrin were increased to 2.52+/-0.21 nmol/L, 20.88+/-2.52 ng/mL, 33.8+/-2.9 microg/L, and 69% positive, respectively, compared with control subjects (0.86+/-063 nmol/L, 1.14+/-0.15 ng/mL, 16.07+/-1.01 microg/L, and 0%, respectively). Beta-Thromboglobulin and the beta-thromboglobulin-to-platelet factor 4 ratio were also increased to 107.87+/-11.87 IU/mL and 8.86+/-1.06, compared with controls (18.36 +/-2.99 IU/mL and 2.67+/-0.52, respectively). With the exception of a decrease in factor XII and an increase in fibrinogen, coagulation factors, global coagulation tests, and PTL were not changed in sepsis. In severe sepsis and mainly in septic shock, coagulation factors were markedly decreased, global coagulation tests were prolonged, and PTL was reduced. All changes were independent of the causative infectious pathogen.. Coagulation system and platelets are strongly activated in sepsis. In this stage, only factor XII is decreased. In contrast, in severe sepsis and mainly in septic shock, most of the coagulation factors are depleted, PTL is decreased, and global coagulation tests are prolonged, indicating exhaustion of hemostasis. Finally, Gram-positive, Gram-negative, and other microorganisms produce identical impairment of coagulation.

Topics: Adolescent; Adult; Aged; Antithrombin III; Biomarkers; Blood Coagulation Disorders; Blood Coagulation Tests; Case-Control Studies; Female; Fibrinopeptide A; Humans; Male; Middle Aged; Peptide Fragments; Peptide Hydrolases; Platelet Activation; Platelet Count; Prospective Studies; Protein Precursors; Prothrombin; Sepsis; Severity of Illness Index; Shock, Septic

The aim of this study was to determine whether paroxysmal atrial fibrillation (PAF) and/or restoration to sinus rhythm with electric or pharmacologic cardioversion induce modifications to the coagulation system. Thirty-five patients with PAF undergoing either electric (n = 11) or pharmacologic (n = 24) cardioversion were studied. Fibrinopeptide A and D-dimer blood samples were taken immediately before and after cardioversion at different intervals. When compared with the control group (n = 70), the precardioversion fibrinopeptide A plasma values were significantly elevated (11.8 vs 2.5 ng/mL). Fibrinopeptide A plasma values were significantly reduced 5 minutes after cardioversion (11.8 vs 5.3 ng/mL) and remained stable throughout the follow-up sequential measurements. D-dimer plasma values were significantly increased (measured at 12 hours and at day 7) in patients who underwent electrical cardioversions only. A positive correlation (R(2) = 0.76) was found between the energy delivered for cardioversion to sinus rhythm and D-dimer plasma values on day 7. In patients with PAF, levels of fibrinopeptide A, an indicator of coagulation activation, are elevated and soon reduced by the restoration of sinus rhythm. Electric, but not pharmacologic, cardioversion induces an early activation of the fibrinolytic system.

Topics: Aged; Atrial Fibrillation; Blood Coagulation Disorders; Electric Countershock; Female; Fibrin Fibrinogen Degradation Products; Fibrinolysis; Fibrinopeptide A; Humans; Male; Middle Aged; Prospective Studies

Thrombin-induced cleavage of fibrinopeptide A is the initial step in the conversion of fibrinogen to fibrin. Three dysfunctional fibrinogen variants are described with an amino acid substitution at position 16 of the Aalpha-chain: the fibrinogen variants Bern IV and Milano XI having an Arg-->His substitution and the variant Bern V having an Arg-->Cys substitution. Routine coagulation studies revealed prolonged plasma thrombin and reptilase clotting times in all patients, and a discrepancy between the plasma levels of fibrinogen determined by the clotting assay and electroimmunoassay. The defect was localized by high-performance liquid chromatography analysis of fibrinopeptide release and confirmed by polymerase chain reaction and sequencing of exon 2 of the Aalpha-chain. Immunoblotting analysis with a rabbit antiserum against human serum albumin indicated that albumin was linked to the additional sulfhydryl group of fibrinogen Bern V. The assay of tissue-plasminogen-activator-induced plasmic degradation revealed that the fibrinolysis of fibrin Bern V was delayed, whereas fibrin Bern IV was digested in the same way as normal fibrin.

Topics: Adult; Amino Acid Substitution; Binding Sites; Blood Coagulation Disorders; Chromatography, High Pressure Liquid; DNA Mutational Analysis; Female; Fibrinogens, Abnormal; Fibrinolysis; Fibrinopeptide A; Humans; Infant; Male; Middle Aged; Plasminogen; Serum Albumin; Thrombin; Thrombin Time; Tissue Plasminogen Activator

To assess coagulation activation and endothelial cell injury in normotensive and pre-eclamptic pregnant women, a comparison was made of plasma levels of tissue factor, fibronectin, fibrinopeptide A and D-dimer. Samples were taken from 50 nonpregnant women, 40 normotensive pregnant women in the third trimester and 27 women with pre-eclampsia after diagnosis and before treatment. High levels of fibrinopeptide A and D-dimer were found in pre-eclamptic women. Moreover, the ratio fibrinopeptide A:D-dimer was much greater in the pre-eclampsia group than in normotensive pregnant women. The levels of fibronectin and tissue factor were also higher in the pre-eclampsia group. The increase of tissue factor levels suggests an alteration of the extrinsic coagulation pathway in pre-eclampsia. The increase of fibrinopeptide A:D-dimer ratio shows that the activation of coagulation is associated with a relative hypofibrinolysis in pre-eclampsia.

Topics: Adult; Antifibrinolytic Agents; Blood Coagulation Disorders; Female; Fibrin Fibrinogen Degradation Products; Fibrinopeptide A; Gestational Age; Humans; Pre-Eclampsia; Pregnancy; Thromboplastin

To test the hypothesis that an impaired coagulation system facilitates rapid expansion of hypertensive intracerebral hemorrhage (HICH), coagulation markers were assayed in plasma and their relations to both the hemorrhage size and its progressive expansion were analyzed. Ninety patients with HICH were studied. On admission, plasma samples were taken for the coagulation assay. Hematoma volume was calculated from a computed tomography (CT) scan and its enlargement was estimated by comparison to the volume of the hematoma calculated from a second CT scan taken later within 24 hr. Nine out of 90 patients showed enlargement in their hematoma size (enlarged hematoma group). Four of the enlarged hematoma group fell into acute fatal deterioration and died. Plasma levels of both fibrino peptide A (17.2+/-7.8 vs. 4.0+/-0.6 ng/ml, P < 0.05) and thrombin-antithrombin complex (21.9+/-3.1 vs. 7.4+/-2.8 ng/ml, not significant) were higher in the unchanged group than those in the enlarged hematoma group. In the hematoma-enlarged group fibrino-peptide A level did not exceed 10 ng/ml. In the hematoma unchanged group thrombin-AT-III complex values were positively correlated to hematoma volume. Thus, the coagulation system seemed to be highly activated depending on the hemorrhage volume within three hr after ictus in hypertensive intracerebral hemorrhage patients. When thrombin generation was not sufficient after bleeding, the hematoma seemed to be progressively enlarged. In conclusion, plasma levels of the coagulation markers on admission could be useful predictors of the possible enlargement of hematoma which leads to a poor outcome.

Topics: Aged; Aged, 80 and over; Antithrombin III; Blood Coagulation Disorders; Cerebral Hemorrhage; Disease Progression; Female; Fibrinogen; Fibrinopeptide A; Hematoma; Humans; Incidence; Intracranial Hypertension; Male; Middle Aged; Peptide Hydrolases; Platelet Count; Prothrombin Time

To obtain systematic information on the extrinsic coagulation pathway, as well as to investigate the time course of the coagulation abnormalities in sepsis.. Prospective observational study.. General intensive care unit.. Nineteen patients with the diagnosis of severe sepsis or septic shock and nine control patients.. None.. Tissue factor antigen concentration (tissue factor antigen), prothrombin fragment F1+2, thrombin antithrombin III complex, fibrinopeptide A, D-dimer, and antithrombin III concentrations were measured on the day of diagnosis of severe sepsis and septic shock, and on days 1, 2, 3, and 4 after diagnosis. The concentrations of tissue factor antigen, prothrombin fragment F1+2, fibrinopeptide A, and D-dimer were significantly increased in patients with severe sepsis and septic shock compared with control subjects. However, the concentrations of thrombin antithrombin III complex showed no statistical differences between the septic patients and the control subjects. Significantly, low antithrombin III concentrations were observed in the septic patient groups compared with control subjects. With the exception of D-dimer, the concentrations of the hemostatic markers were similar between severe sepsis and septic shock patients. Significant correlations were noted between tissue factor antigen and the disseminated intravascular coagulation score (r2=.236, p< .0001) and the number of dysfunctioning organs (r2=.229, p=.035).. We systematically elucidated coagulation disorders in newly defined sepsis. The extrinsic coagulation pathway is activated in patients with severe sepsis and septic shock. In these patients, enhanced thrombin generation and activation, and fibrin formation were demonstrated when compared with the control subjects. Furthermore, the thrombin generated appears not to be fully neutralized by antithrombin III.

Topics: Adult; Aged; Antithrombin III; Biomarkers; Blood Coagulation; Blood Coagulation Disorders; Case-Control Studies; Female; Fibrin Fibrinogen Degradation Products; Fibrinopeptide A; Humans; Male; Middle Aged; Peptide Fragments; Peptide Hydrolases; Prospective Studies; Protein Precursors; Prothrombin; Sepsis; Shock, Septic; Thromboplastin

Since it has not been established to what extent abnormalities of hemostasis contribute to the occurrence and development of dementia, selected measurements of coagulation and fibrinolysis were obtained in elderly patients with Alzheimer's disease (n = 22) or vascular dementia (n = 29), compared with healthy individuals in the same age range (n = 61). Hemostasis abnormalities were more frequent and marked in vascular dementia, being expressed as significant increases of plasminogen activator inhibitor type 1, von Willebrand factor, D-dimer and activated factor VII. However, some hemostasis measurements (von Willebrand factor, activated factor VII) were abnormally high also in the patients with Alzheimer's disease, a condition in which vascular damage is not considered to play a major pathogenetic role. It could not be established in this study whether or not these hemostatic abnormalities play a casual role in the pathogenesis of dementia, or whether they are secondary to inflammation and chronic vascular disease. Nevertheless, their presence may contribute to aggravating vascular disease.

Topics: Aged; Alzheimer Disease; Blood Coagulation; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Proteins; Dementia, Vascular; Female; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinolysis; Fibrinopeptide A; Humans; Male; Peptide Fragments; Prothrombin

To test the hypothesis that disseminated intravascular coagulation contributes to hemostatic failure in liver cirrhosis, fibrinopeptide A and fibrin(ogen) degradation fragment E were measured in 69 patients with stable liver cirrhosis and compared with fibrinopeptide A and fibrin(ogen) degradation fragment E in 32 healthy subjects, 33 patients with thromboembolism, and 10 patients with hypofibrinogenemic disseminated intravascular coagulation. Mean fibrinopeptide A in cirrhosis was slightly increased compared with healthy subjects (2.4 vs. 1.8 ng/ml, p < 0.005), but fourfold lower than in thromboembolism (mean fibrinopeptide A 9.7 ng/ml; p < 0.0001), and tenfold lower than in disseminated intravascular coagulation (mean FPA 24.3 ng/ml; p < 0.0001). Single fibrinopeptide A levels in cirrhosis were within the normal range in 75% of the patients, marginally increased in 9%, and definitely increased in 16%. A definite increase in both fibrinopeptide A and fibrin(ogen) degradation fragment E, which characterized the groups of patients with thromboembolism and disseminated intravascular coagulation, was found in 10% of the cirrhotic patients. Among 17 patients with cirrhosis and hypofibrinogenemia, mean fibrinopeptide A (2.7 ng/ml) was tenfold lower compared with mean fibrinopeptide A in patients with hypofibrinogenemic disseminated intravascular coagulation (p < 0.0001), whereas the frequency of increased single fibrinopeptide A levels (29%) was not significantly different compared with the 52 cirrhotic patients without hypofibrinogenemia (single levels elevated in 23% of the cases). Moreover, the frequency of hypofibrinogenemia, thrombocytopenia, or abnormal clotting times was not significantly different in cirrhotic patients with normal fibrinopeptide A level when compared with cirrhotic patients with increased fibrinopeptide A. These findings do not support an important contribution of disseminated intravascular coagulation to coagulopathy of liver cirrhosis.

Topics: Adult; Aged; Blood Coagulation Disorders; Blood Coagulation Tests; Disseminated Intravascular Coagulation; Female; Fibrin Fibrinogen Degradation Products; Fibrinopeptide A; Humans; Liver Cirrhosis; Male; Middle Aged; Reference Values; Thromboembolism

Heparin is indispensable anticoagulant for cardiopulmonary bypass, but the dose of heparin is even now under discussion. In this study, hemostatic fluctuation was analyzed during and after the bypass using hemostatic molecular markers. The subjects were 16 adult cases of open heart surgery, 12 males, 4 females. The average age was 55.0 year. Operations were aortocoronary bypass in 12, valvular surgery in 3 and ASD patch closure in one with moderate hypothermic cardiopulmonary bypass. At the beginning of cardiopulmonary bypass, 3 mg/kg heparin was administered and the equivalent amount of protamine sulfate was used for neutralization at the end of the bypass. Platelet count, hematocrit, antithrombin III (ATIII), beta-thromboglobulin, platelet factor 4, fibrinopeptide A, thrombin antithrombin III complex, FDP, D dimer FDP, plasmin alpha 2 plasmin inhibitor complex, tissue plasminogen activator (t-PA), and thrombomodulin (TM) were measured through the operation up to two weeks after surgery. ATIII decreased to 50% of control value all through the bypass. Platelet markers increased immediately, and the activated state continued 3 hours after the bypass. Coagulation markers increased markedly after the aortic declamping, and reached at its peak by three times as control value, immediately after the protamine neutralization and continued for 3 hours. During the bypass, fibrinogenolysis caused by t-PA which was stimulated by non-physiological circulation and stimulating substances, was observed. Fibrinolysis occurred following the hypercoagulability after the neutralization. TM was within normal range before the aortic declamping. But increased gradually after the declamp, and reached twice as much as the base line. It could be concluded that hypercoagulability and high platelet activation might play a role of perioperative thrombosis. Hypercoagulability and increase of serum TM would be related to reperfusion of the lung. The increasing of TM would reflect broad injury of vessel walls after the bypass, because plasma TM increased following the generalized injury of endothelial cells.

Topics: Adult; Aged; Antithrombin III; beta-Thromboglobulin; Blood Coagulation; Blood Coagulation Disorders; Cardiopulmonary Bypass; Coronary Disease; Female; Fibrin Fibrinogen Degradation Products; Fibrinopeptide A; Hematocrit; Humans; Male; Middle Aged; Platelet Count; Receptors, Cell Surface; Receptors, Thrombin

The coagulative system has an important role on haemodialysis and on atherosclerosis genesis; in particular the platelets are key elements of the coagulation and of atherosclerosis phenomena. Alterations of the coagulative system and increase risk of developing atherosclerosis are reported in the aging. We in this paper, report the results obtained studying the influence of the interaction between the elderly and dyslipidemia on the coagulative system in haemodialyzed patients. The obtained data showed that the hypertriglyceridaemia in interaction with the elderly accelerates and increases platelet aggregation after stimulation by ADP, Epinephrine and Collagen. So, it is important to consider hypertriglyceridaemia and age as thrombogenic factors and atherosclerosis accelerating factors in haemodialyzed patients.

Topics: Adenosine Diphosphate; Age Factors; Aged; Arteriosclerosis; beta-Thromboglobulin; Blood Coagulation Disorders; Collagen; Epinephrine; Fibrinopeptide A; Humans; Hypertriglyceridemia; Middle Aged; Platelet Aggregation; Renal Dialysis; Thrombin; Uremia

We describe a 50-year-old man with a severe acquired haemorrhagic syndrome. He had slightly prolonged clotting times using bovine thrombin, human thrombin and reptilase. His plasma contained a polyclonal IgG which interfered with the generation of fibrin monomers without inhibiting the aggregation of preformed monomers. The inhibitor delayed thrombin-induced fibrinopeptide A release. The IgG bound to insolubilized synthetic fibrinopeptide A (one binding site per molecule) and, with higher affinity, to fibrinogen (two binding sites per molecule). It did not bind to insolubilized fibrin monomers. The IgG did not impair the catalytic activity of thrombin toward a small synthetic substrate but inhibited the binding of thrombin to fibrinogen without binding to thrombin. The binding of the anti-fibrinopeptide A autoantibody to fibrinogen might have impaired thrombin-induced fibrinogen to fibrin conversion in vivo. This may have favoured the reported haemorrhagic syndrome which was associated with severe chronic renal insufficiency.

Topics: Autoantibodies; Binding Sites; Blood Coagulation Disorders; Fibrin; Fibrinogen; Fibrinopeptide A; Hemorrhage; Humans; Immunoglobulin G; Kidney Failure, Chronic; Male; Middle Aged; Thrombin

Haemostatic changes in 16 patients with Crohn's disease were studied from active disease into clinical remission and beyond. Elevated concentrations of fibrinopeptide A (FpA) and prothrombin fragments F1 + 2 (F1 + 2) were found at times of both active (FpA median 3.2, range [0.3-40] ng/ml and F1 + 2 median 2.3, range [0.3-18] nm/l) and inactive disease (FpA median 2, range [0.4-40] ng/ml and F1 + 2 median 1.3, range [0.2-20) nm/l]. We also measured the physiological inhibitors of coagulation and fibrinolysis; there was no significant difference in the levels of antithrombin III, protein C or the Exner ratio between active and inactive disease. Free protein S levels were significantly lower in active disease (median 34, range 9-54 U/dl) than in remission (median 40, range 12-65 U/dl). Plasminogen activator inhibitor type 1 (PAI-1) was significantly raised in remission (median 11, range 3-32 ng/ml) when compared to active disease (median 7, range 3-42 ng/ml). The D-dimer correlated significantly with fibrinopeptide A (P < 0.001), suggesting reactive fibrinolysis in some patients. Most (35/52, 67%) samples showed evidence of persistent haemostatic activation (elevated FpA and/or F1 + 2) during phases of apparent clinical remission in Crohn's disease, a factor that is not reflected by clinical activity scores. This study supports the hypothesis that coagulation is activated in the mesenteric vasculature of patients with Crohn's disease.

Topics: Adolescent; Adult; Aged; Blood Coagulation; Blood Coagulation Disorders; Crohn Disease; Female; Fibrinolysis; Fibrinopeptide A; Humans; Lupus Coagulation Inhibitor; Male; Middle Aged; Peptide Fragments; Prothrombin; Severity of Illness Index

Topics: Adult; Blood Coagulation Disorders; Female; Fibrin Fibrinogen Degradation Products; Fibrinopeptide A; Fibrinopeptide B; Humans; Hypothyroidism; Male; Middle Aged; Peptide Fragments

To determine the effects of disseminated intravascular coagulation (DIC) and head injury on posttrauma coagulation and fibrinolysis.. Case-control study.. General ICU (tertiary care center) in a city hospital serving a population of 150 million people.. Forty trauma victims: 15 with DIC; 25 without DIC.. Measurement of six types of coagulation and fibrinolytic molecular markers (fibrinopeptide A, fibrinopeptide B beta 15-42, plasmin antiplasmin complex, D-dimer, tissue plasminogen activator antigen concentration, tissue plasminogen activator activity) immediately after trauma, 3 days later, and 6 days later. Anticoagulant treatment with gabexate mesilate at 1.45 +/- 0.06 mg/kg/hr.. Fibrinopeptide A, fibrinopeptide B beta 15-42, plasmin antiplasmin complex, and D-dimer showed high values immediately after trauma and exceeded normal activity for the first 6 days. When trauma was complicated with DIC, the molecular markers showed significantly higher values than those for non-DIC patients on all days. In the head-injured patients, such effect was not noted. Tissue plasminogen activator antigen concentration and tissue plasminogen activator activity were within a normal physiologic range of variation. By contrast, tissue plasminogen activator antigen concentration increased significantly after trauma in patients with DIC. When anticoagulant treatment was found effective, it caused a reduction in fibrinopeptide A.. a) Fibrinolytic shut-down and its reactivation cannot be confirmed after trauma. b) Head injury does not lead to an increase in posttrauma coagulation or fibrinolytic activity. c) DIC enhances posttrauma coagulation and fibrinolytic activity and plasminogen activator inhibitor activity can be inferred in DIC patients. d) Increase in tissue plasminogen activator antigen concentration without tissue plasminogen activator activation may be a prognostic factor indicative of DIC and its chances of improvement, and fibrinopeptide A as an assessment criterion for the effectiveness of anticoagulant treatment.

Topics: Adult; Antifibrinolytic Agents; Antigen-Antibody Complex; Antigens; Antithrombin III; Biomarkers; Blood Coagulation Disorders; Case-Control Studies; Craniocerebral Trauma; Disseminated Intravascular Coagulation; Female; Fibrin Fibrinogen Degradation Products; Fibrinolysin; Fibrinolysis; Fibrinopeptide A; Fibrinopeptide B; Glasgow Coma Scale; Hospitals, General; Humans; Injury Severity Score; Japan; Male; Middle Aged; Multiple Trauma; Partial Thromboplastin Time; Platelet Count; Predictive Value of Tests; Prothrombin Time; Tissue Plasminogen Activator

A congenital fibrinogen variant in a German family is described which has been identified as a substitution of His in position 16 of the A alpha-chain for Arg, manifested over three generations in heterozygous form. The characterization is based on the reaction of the variant fibrinogen with thrombin and reptilase, on the HPLC-chromatographic properties and the amino acid composition of the abnormal fibrinopeptide A. Clinical observations in the affected family members (neither haemorrhagic nor thrombophilic tendencies), the results of routine coagulation tests (normal global clotting tests, prolonged thrombin and thrombin-coagulase time, decreased fibrinogen concentration in functional as opposed to immunological tests), and the autosomal co-dominant modus of inheritance of the fibrinogen variant are all in complete agreement with other reports in the literature concerning the same amino acid exchange. The results of our experiments with fibrinogen Kiel allow no definite conclusion regarding the question of whether it consists of pure homodimers or as of a mixture of homo- and heterodimers.

Topics: Amino Acids; Arginine; Blood Coagulation Disorders; Chromatography, High Pressure Liquid; Coagulase; Fibrinogens, Abnormal; Fibrinopeptide A; Histidine; Humans; Macromolecular Substances; Male; Middle Aged; Pedigree; Thrombin Time

A heterozygous hereditary fibrinogen variant, fibrinogen Bern III, has been characterized. The proposita and her daughter showed prolonged thrombin time and reptilase time, as well as a markedly reduced fibrinogen concentration as determined by functional clotting assay. Fibrinogen was purified from the proposita's plasma and subjected to biochemical characterization. The delayed fibrin formation was shown to result from impaired release of fibrinopeptide A. Thrombin was found to cleave an extended fibrinopeptide A (A alpha 1-19) from the reduced polypeptide chains of the abnormal fibrinogen. Amino acid analysis of this fragment indicated that the arginine residue, located at the physiological thrombin cleavage site, was replaced by cysteine. The functional defect of the fibrinogen variant Bern III is due to the amino acid substitution A alpha 16 Arg----Cys.

Topics: Adult; Arginine; Blood Coagulation Disorders; Cysteine; Female; Fibrinogens, Abnormal; Fibrinopeptide A; Humans; Middle Aged; Pedigree; Prothrombin Time; Thrombin

Fibrinogen Ledyard was discovered in a 10-year-old boy with a mild bleeding history. His father had the same defect and a bleeding history after surgery. Both patients were heterozygous. The plasma fibrinogen concentration was normal immunologically (335 mg/dL) and very low functionally (52 mg/dL). Purified fibrinogen Ledyard had a prolonged polymerization, which was somewhat corrected by addition of Ca2+ ions. High performance liquid chromatography (HPLC) analyses of the fibrinopeptides released by thrombin showed 1 mol of fibrinopeptide A (FPA) and 2 mol of fibrinopeptide B (FPB) released per mole of fibrinogen Ledyard. Steady-state kinetic parameters were evaluated for release of FPA by thrombin. When the concentration of fibrinogen Ledyard was corrected to 50% of total protein, because only 50% of fibrinogen Ledyard can release FPA, the kinetic constants were similar to those of control fibrinogen (Km = 7.5 mumol/L for A alpha chain, kcat = 54 s-1). This finding indicates that the cleavage site of the A alpha chain in these abnormal molecules may not interact with the catalytic site of thrombin. The three chains of fibrinogen Ledyard were isolated on reverse-phase C4-HPLC. The sequence of the amino terminus of A alpha chain showed that Arg in position 16 was replaced by Cys in the abnormal molecules. Approximately half of fibrinogen Ledyard (52%) was clotted by reptilase, suggesting that fibrinogen Ledyard may consist of 50% normal homodimers (A alpha Arg16 . A alpha Arg16) and 50% abnormal homodimers (A alpha Cys16 . A alpha Cys16). Abnormal molecules could form disulfide bond between the A alpha Cys16 residues. Thus, the abnormal molecules have a different structure that does not bind to thrombin. Probably the abnormality of polymerization of fibrinogen Ledyard results from the interaction of the abnormal molecules with normal fibrin monomers, so that the growth of fibrin protofibrils is inhibited. This abnormal fibrinogen supports adenosine diphosphate-induced platelet aggregation in a normal manner.

Topics: Amino Acid Sequence; Arginine; Blood Coagulation Disorders; Calcium; Child; Chromatography, High Pressure Liquid; Cysteine; Fibrinogens, Abnormal; Fibrinopeptide A; Fibrinopeptide B; Humans; Macromolecular Substances; Male; Molecular Sequence Data; Platelet Aggregation

Congenital dysfibrinogenaemia was found in a 39-year-old female and her two children. The proposita, apparently heterozygous for this abnormality, had no episode of bleeding or thrombosis. The abnormal fibrinogen showed normal release of fibrinopeptides A and B but impaired polymerization of the fibrin monomer. Amino acid sequence analysis of the whole A alpha-chain isolated from fibrinogen Kanazawa showed a substitution of Leu for Pro at position 18 in the A alpha-chain. This substitution was corroborated by the analysis of the amino acid sequence which demonstrated the lysyl endopeptidase peptides derived from the A alpha-chain of fibrinogen Kanazawa. The minimal genetic exchange responsible for this substitution was a C----T transition in the middle position of the Pro codon. We conclude that Pro-18 in the A alpha-chain is crucial for the polymerization of the fibrin monomer.

Topics: Adult; Amino Acid Sequence; Blood Coagulation Disorders; Blood Coagulation Tests; Female; Fibrinogens, Abnormal; Fibrinopeptide A; Fibrinopeptide B; Humans; Leucine; Molecular Sequence Data; Polymers; Proline

A new case of heterozygous dysfibrinogenemia characterized by the replacement of NH2-terminal amino acid of fibrin beta-chain was found in a 50-year-old man. Despite a prolonged thrombin time, the propositus' fibrinogen had a normal reptilase time with the normal release of fibrinopeptide A. Release of fibrinopeptide B by thrombin was strongly affected, but a very high concentration of thrombin almost completely released fibrinopeptide B with a normal elution pattern on reversed-phase high performance liquid chromatography (HPLC). Lysylendopeptidase-cleavage of purified B beta-chains analyzed on HPLC showed the decrease of one peptide compared with the normal and the appearance of an abnormal peptide peak. These peptides were treated with thrombin and further separated on HPLC. Amino acid sequence analysis of the abnormal peptide demonstrated that B beta glycine-15, NH2-terminus of the fibrin beta-chain, was replaced by cysteine. These findings will be of particular importance because they strongly support the hypothesis that the NH2-terminal portion of the fibrin beta-chain is involved in the polymerization reaction by thrombin. The propositus' daughter and two sisters had the same abnormal fibrinogen. This unique inherited abnormal fibrinogen was designated as fibrinogen Ise. During these studies, we found that a very high concentration of thrombin cleaves not only the A alpha Arg19-Val20 bond but also the COOH-terminal region of alpha-chains, which results in the generation of further degraded alpha-chains with apparent molecular weights of 44,000 or less.

Topics: Amino Acid Sequence; Batroxobin; Blood Coagulation Disorders; Blood Coagulation Tests; Chromatography, High Pressure Liquid; Cysteine; Fibrin; Fibrinogens, Abnormal; Fibrinopeptide A; Fibrinopeptide B; Glycine; Humans; Male; Middle Aged; Molecular Sequence Data; Thrombin

Fibrinogen Baltimore I is one of the very first congenital abnormal fibrinogens reported over several decades ago; however, the molecular defect of this dysfibrinogen has eluded identification. In fact, several reports misidentified the functional defect of Baltimore I, which has impaired fibrin monomer polymerization. Reversed-phase high-performance liquid chromatography analysis of lysyl endopeptidase digest of the purified Baltimore I gamma-chain showed an abnormal peptide not found in the co-existing normal gamma-chain of this heterozygote. Amino acid sequencing of this peptide indicated that gamma-chain Gly292 is replaced by valine. This observation was confirmed, and the genetic defect was determined by direct nucleotide sequencing of a polymerase chain reaction product containing codon gamma 292, which is mutated: GGC----GTC. The molecular defect of Fibrinogen Baltimore I lies in a region of the gamma-chain required for fibrin polymerization, suggesting that the integrity of gamma Gly292 is critical for fibrin assembly.

Topics: Adult; Amino Acid Sequence; Base Sequence; Blood Coagulation Disorders; Chromatography, High Pressure Liquid; Codon; Female; Fibrinogens, Abnormal; Fibrinopeptide A; Fibrinopeptide B; Glycine; Humans; Molecular Sequence Data; Mutation; Polymers; Serine Endopeptidases; Valine

The mean levels of fibrinopeptide A (FPA), thrombin-antithrombin complex (TAT), and soluble fibrin (tPA method) in cancer patients (n = 32) were intermediate between those of patients with cerebral infarction and pancreatitis who had the most abnormal results and patients with myocardial infarction and pneumonia who had the least abnormal results. Patients with disseminated malignancies (n = 16) had significantly higher mean levels of FPA (10.6 vs. 5.3 nmol/l) and TAT (11.0 vs. 4.4 pmol/l) than patients with limited malignancies (n = 16). The difference in soluble fibrin (fibrin monomer, FM; 22.1 vs. 18.0 nmol/l) was not significant. The values of FPA, FM, and TAT in the patient population correlated significantly. There was a negative correlation between the level of antithrombin and test results for FPA (-0.69), FM (-0.48), and TAT (-0.38) in the cancer patients. Even cancer patients with locally limited disease may have elevated FPA, FM, and TAT test results, indicating a state of definite hypercoagulation.

Topics: Acute Disease; Adult; Aged; Aged, 80 and over; Antithrombin III; Blood Coagulation Disorders; Blood Coagulation Tests; Cerebral Infarction; Female; Fibrin; Fibrinopeptide A; Humans; Male; Middle Aged; Myocardial Infarction; Neoplasms; Pancreatitis; Peptide Hydrolases; Pneumonia; Predictive Value of Tests; Reference Values

We describe a new congenital dysfibrinogenemia: fibrinogen Barcelona II in 8 members of a family with no major bleeding or thrombotic tendency. Incubation of this fibrinogen with thrombin at low concentration releases half of the expected normal fibrinopeptide A (FPA) and with some delay it releases an abnormal FPA. Abnormal FPA was purified and sequenced and showed a change in the normal amino acid sequence: arginine in position 16 has been substituted by a histidine. This is another case of dysfibrinogenemia in which A alpha 16 Arg----His has been identified as the cause of abnormal behavior of the fibrinogen molecule.

Topics: Amino Acid Sequence; Blood Coagulation Disorders; Blood Coagulation Tests; Chromatography, High Pressure Liquid; Fibrinogen; Fibrinogens, Abnormal; Fibrinopeptide A; Humans; Kinetics; Male; Middle Aged; Pedigree

Congenital heterozygous dysfibrinogenemia was diagnosed in a young woman with bleeding tendency. 3 other asymptomatic members of her family (mother and the 2 sisters) had abnormal fibrinogen. The proposita's plasma exhibited prolonged thrombin and reptilase times. Plasma fibrinogen concentration determined by functional assay was 0.3 g/l, whereas immunologic assay revealed normal fibrinogen levels. Turbidity curves, representing the rate of thrombin-induced fibrin formation, were markedly delayed both in the presence and absence of Ca2+. Isoelectric focusing and SDS electrophoresis of reduced fibrinogen showed normal charge and size of the subunit chains. Release of fibrinopeptide B by thrombin was normal, whereas HPLC elution diagrams of fibrinopeptide A showed an abnormal peak A* with a slightly shorter retention time than the normal fibrinopeptide A. The amino acid analysis showed that the arginine in peak A* is replaced by histidine (A alpha 16 Arg----His).

Topics: Adolescent; Amino Acids; Blood Coagulation Disorders; Calcium; Electrophoresis, Polyacrylamide Gel; Fibrinogens, Abnormal; Fibrinopeptide A; Fibrinopeptide B; Heterozygote; Humans; Isoelectric Focusing; Kinetics; Male; Pedigree; Platelet Aggregation; Thrombin

To clarify the mechanism which causes the coagulation time of fetal fibrinogen to be longer than that of adult fibrinogen, the N-terminal amino acid residues of fetal fibrinogen were analyzed. The results showed that the amount of A alpha chain's N-terminal alanine residues in fetal fibrinogen was only 54% of that in adult fibrinogen. When the amount of A alpha chain's N-terminal residual alanine in adult fibrinogen was decreased to 57% of the normal level by digestion with aminopeptidase M, the adult fibrinogen yielded a prolonged thrombin time and a retarded release rate for fibrino-peptides A and B, both values approximating to those of fetal fibrinogen. The results suggest that the deficiency in alanine residue at the N-terminus of the A alpha chain is a major cause of the slow coagulation of fetal fibrinogen.

Topics: Alanine; Amino Acids; Aminopeptidases; Blood Coagulation Disorders; CD13 Antigens; Electrophoresis, Polyacrylamide Gel; Fetal Blood; Fibrinogen; Fibrinopeptide A; Fibrinopeptide B; Glycine; Humans; Infant, Newborn; Thrombin Time

Topics: beta-Thromboglobulin; Blood Coagulation Disorders; Fibrinopeptide A; Hemostasis; Humans; Receptors, Cell Surface; Receptors, Thrombin; Thromboembolism; Tissue Plasminogen Activator

Congenital dysfibrinogenemia was found in a patient with venous thrombosis. Blood clot lysis was prolonged and suggested an impairment of fibrinolysis. We investigated whether this was related to the fibrinogen abnormality. Fibrinopeptide release was normal but fibrin polymerization was defective in the patient. The stimulating effect of the patient's fibrin on t-PA mediated plasminogen activation was impaired. This could not be attributed to defective binding of plasminogen. However, the binding of t-PA to the patient's fibrin was about 16% less than to normal fibrin. A variant t-PA (G K1 K2 P), which contained only one of the two fibrin binding sites, i.e. the kringle-2 domain, was bound to the abnormal fibrin for only 50% of normal. We conclude that the prolongation of blood clot lysis and the impaired stimulation of t-PA mediated plasminogen activation are related to the defective binding of the kringle-2 domain of t-PA onto the fibrin moiety of the abnormal fibrinogen. The impairment of fibrinolysis might explain the occurrence of thrombosis in the patient.

Topics: Blood Coagulation Disorders; Fibrinogen; Fibrinogens, Abnormal; Fibrinopeptide A; Fibrinopeptide B; Humans; Male; Middle Aged; Pedigree; Plasminogen; Protein Binding; Thrombophlebitis; Tissue Plasminogen Activator; Whole Blood Coagulation Time

Fibrinogen was isolated from the plasma of a 25-year-old female with a history of mild bleeding and several recent moderate to severe hemorrhagic episodes. Coagulability with thrombin approached 100% and varied directly with the time of incubation with the enzyme. High-performance liquid chromatography analysis of thrombin-induced fibrinopeptide release demonstrated retarded fibrinopeptide A (FPA) and fibrinopeptide B (FPB) release and the presence of an abnormal A peptide (FPA) amounting to 50% of the total. The same biochemical abnormalities were found in her asymptomatic father. Amino acid analysis and carboxypeptidase digestion of FPA demonstrated the substitution of His for Arg at A alpha 16. In contrast to the thrombin- and reptilase-sensitive Arg-Gly bond in the normal A alpha chain, the abnormal A alpha chain (A alpha) sequence is resistant to reptilase attack but is slowly cleaved by thrombin. To evaluate whether Birmingham A alpha and A alpha chains had been assembled nonselectively into heterodimeric (ie, 50% A alpha, A alpha) and homodimeric (ie, 25% A alpha, A alpha; 25% A alpha, A alpha) species, the clot and the clot liquor resulting from reptilase treatment of normal or Birmingham fibrinogen were separated, and each was then further incubated with thrombin to release remaining fibrinopeptides. Assuming that fibrinogen Birmingham contained heterodimeric molecules and that these and the normal molecules were completely incorporated into a reptilase clot, the expected coagulability would be 75%. In addition, subsequent thrombin treatment of the reptilase clot would release 50% of the total FPA and 75% of the total FPB present in the original sample. On the other hand, if only homodimeric fibrinogen species (50% A alpha, A alpha; 50% A alpha, A alpha) existed, the maximum reptilase coagulability would be 50%, and after thrombin treatment, 50% of the total FPB and no FPA would be recovered from the reptilase clot. We found the propositus's fibrinogen to be 68% coagulable, and we recovered 45% of the FPA and 70% of the FPB from the reptilase clot. Essentially the same coagulability and distribution of fibrinopeptides was found in the reptilase clot from her father's fibrinogen. We therefore conclude that fibrinogen Birmingham contains heterodimeric species (A alpha, A alpha) amounting to approximately 50% of the circulating fibrinogen molecules. The existence of heterodimers is consistent with a nonselective intracellular process of constituent

Topics: Adult; Amino Acids; Blood Coagulation Disorders; Female; Fibrin; Fibrinogen; Fibrinogens, Abnormal; Fibrinopeptide A; Heterozygote; Humans

The activation of platelets and the coagulation mechanism was studied by collecting blood from a standard bleeding time incision at 30-second intervals and measuring the plasma concentrations of fibrinopeptide A (FPA), platelet factor 4 (PF4), and thromboxane B2 (TxB2). FPA was observed in the first samples (30 to 60 seconds) obtained, increased progressively until cessation of bleeding, and was markedly diminished after heparin administration, thus indicating that thrombin formation occurs early in incisional blood. PF4 increased monotonically throughout blood sampling, whereas the major increase in TxB2 appeared near the cessation of bleeding. The initial increase in FPA content occurred normally in patients with deficiencies of either factor IX or VIII, was markedly diminished in patients with factor X or V deficiency, and was delayed in patients with factor VII deficiency. These studies suggest that tissue factor activation of the classic (activation of factor X) extrinsic coagulation mechanism occurs as an early event during the arrest of bleeding from bleeding time incisions. The relation of the aforementioned to platelet activation is less clear because there was no consistent correlation between decreased FPA formation and impaired PF4 secretion or TxB2 production. In fact, the latter were normal in some subjects with the most impaired FPA formation, which suggests that both collagen and thrombin, perhaps synergistically, may contribute to platelet activation during the primary arrest of bleeding.

Topics: Biomechanical Phenomena; Bleeding Time; Blood Coagulation; Blood Coagulation Disorders; Blood Specimen Collection; Fibrinopeptide A; Humans; Platelet Factor 4; Reference Values; Thromboplastin; Thromboxane B2

An inherited association of dysfibrinogenaemia and protein C deficiency was found in three members of the same family. The propositus was a 48-year-old man who suffered from severe and rapidly complicated atherosclerosis of the aorta and lower limbs arteries, which perhaps suggests that the association of these two molecular abnormalities may have enhanced the thrombotic process. The abnormal fibrinogen had a reduced ability to bind thrombin which may be thrombogenic. We found the same inherited association of dysfibrinogenaemia and protein C deficiency in a patient with venous thrombosis. The functional abnormality of the fibrinogen, which could have been responsible for thrombosis, was delayed proteolysis by plasmin. Not only fibrinogen, but also fibrin clots were resistant to plasmic degradation. These observations raise two questions: (1) Is the association of a protein C deficiency with a dysfibrinogenaemia fortuitous or the result of a common mechanism? (2) Is there a link between an increased thrombotic tendency and either both of the defects of haemostasis that we have found, or only one of them?

Topics: Adult; Blood Coagulation Disorders; Female; Fibrin; Fibrinogen; Fibrinopeptide A; Humans; Infant; Male; Middle Aged; Pedigree; Protein C Deficiency

We describe the coagulopathy of a 65-year-old woman with a thrombotic disorder associated with dysfibrinogenemia and lupus anticoagulant (LA). The patient's prothrombin time (PT), partial thromboplastin time (PTT), thrombin time (TT), and batroxobin time were prolonged and could not be corrected by mixing with equal volumes of normal plasma. Fibrinogen quantitation showed approximately twice as much immunoreactive as thrombin-clottable protein. The batroxobin and thrombin clotting times of the patient's isolated fibrinogen were prolonged and could not be corrected by mixture with normal fibrinogen. Turbidimetrically assessed fibrin monomer aggregation in response to thrombin, ancrod, or batroxobin and fibrin monomer reaggregation experiments disclosed clearly delayed onset and a lower maximum opacity. In other turbidimetric and clotting-time experiments, the patient's fibrinogen displayed a dose-dependent inhibition of the reaggregation of normal fibrin. Fibrinopeptide A and B release rates and sialic acid content were normal. Assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of reduced samples, the subunit structure of the patient's fibrinogen and its fully cross-linked fibrin was normal. The presence of LA was established by two techniques, the blood thromboplastin inhibition test and the platelet neutralization procedure (PNP). A positive PNP could not be produced by mixing afibrinogenemic plasma with the patient's purified fibrinogen. The patient's inactivated serum and her isolated IgG prolonged the PT and PTT of normal plasma but showed no inhibitory effect on the clotting of purified normal fibrinogen.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Blood Coagulation Disorders; Blood Coagulation Factors; Female; Fibrinogen; Fibrinopeptide A; Fibrinopeptide B; Humans; Immunoglobulin G; Lupus Coagulation Inhibitor; Partial Thromboplastin Time; Platelet Aggregation; Prothrombin Time; Thrombophlebitis

A simple method has been developed for the rapid analysis of fibrinopeptides contained on fibrinogen in small anticoagulated plasma samples. Following incubation with thrombin the plasma is diluted, boiled and then studied by high performance liquid chromatography (HPLC). The three forms of FPA (AP, A, AY) and two forms of FPB (B, des Arg B) can be identified and quantified in samples of less than 200 microliters. Additionally, the FPB peak height can be used to measure the plasma fibrinogen level. This method has been used to screen plasma samples with abnormal clotting times for possible congenital fibrinogen abnormalities. Results of the study of nine unrelated cases are presented. Four cases of congenital dysfibrinogenaemia were diagnosed directly from HPLC analysis alone. Fibrinogen Sheffield and Paris VI were identified as A alpha Arg 16----His substitutions and fibrinogens London VI and Madrid II were found to be heterozygous for an unknown substitution preventing thrombin cleavage at A alpha Arg 16. A case of dysfibrinogenaemia (fibrinogen Ashford) with a normal fibrinopeptide release stoichiometry was confirmed to have a primary polymerization abnormality using purified fibrin monomers. Similarly, a case of hypodysfibrinogenaemia (fibrinogen London V) had normal fibrinopeptides and a fibrin polymerization abnormality. In one case of hypofibrinogenaemia and two cases of afibrinogenaemia, no fibrinopeptide or functional abnormalities could be definitely established. This rapid and simple method of fibrinopeptide analysis is recommended for screening of plasma samples taken from patients suspected of having abnormalities of fibrinogen synthesis.

Topics: Blood Coagulation Disorders; Chromatography, High Pressure Liquid; Fibrinogen; Fibrinopeptide A; Fibrinopeptide B; Humans

Topics: Amino Acid Sequence; Blood Coagulation Disorders; Blood Coagulation Tests; Fibrinogen; Fibrinopeptide A; Humans; Structure-Activity Relationship

Topics: Blood Coagulation Disorders; Fibrinopeptide A; Heparin; Humans; Neoplasms; Thrombophlebitis

Fibrinogen Aarhus was found in a woman with slightly prolonged whole blood clotting time. The thrombin induced clotting of plasma and purified fibrinogen was much prolonged. Kinetic analysis of FPA and FPB release revealed larger apparent Km and Vmax values for fibrinogen Aarhus than for normal fibrinogen. No clot formation of fibrinogen Aarhus was demonstrated in the presence of Batroxobin and the release of FPA was slower than normal. Upon addition of the clotting enzyme from Agkistrodon contortrix contortrix clotting did occur but the clotting time was much prolonged in comparison with normal fibrinogen. The turbidity of fibrin gels obtained from fibrinogen Aarhus was similar to normal fibrin gels at low thrombin concentrations. Increasing thrombin concentration resulted in appearance of degradation products in the fibrin gels from fibrinogen Aarhus and at the same time a relative increase in turbidity of the gels was observed. Possibly reasons for the slow release of fibrinopeptides, the delayed gelation, and susceptibility to degradation by thrombin are discussed.

Topics: Adult; Amino Acids; Batroxobin; Blood Coagulation Disorders; Blood Coagulation Tests; Crotalid Venoms; Electrophoresis, Polyacrylamide Gel; Female; Fibrinogen; Fibrinogens, Abnormal; Fibrinolysin; Fibrinopeptide A; Fibrinopeptide B; Gels; Humans; Kinetics; Nephelometry and Turbidimetry; Radioimmunoassay; Thrombin

A congenitally abnormal fibrinogen was isolated from blood of a young man with deep-vein thrombosis. Two other affected members of his family had three episodes of severe arterial thrombosis. The fibrinogen showed a delayed clotting by thrombin, but a normal clotting by Arvin, Reptilase, and prothrombin-staphylocoagulase complex. Analysis of the fibrinopeptides A and B by High Performance Liquid Chromatography did not reveal an abnormal peptide structure. The rate of release of A and B peptides by thrombin was strongly delayed, whereas the rate of release of fibrinopeptide A by Arvin appeared to be normal. The fibrin polymerization rate was normal. Interactions between the abnormal fibrinogen, platelets and the fibrinolytic system were also normal. Evidence is presented that the defective interaction between fibrinogen Milano II and thrombin is associated with a defective binding of thrombin to the fibrin moiety of the abnormal fibrinogen.

Topics: Adult; Blood Coagulation Disorders; Fibrin; Fibrinogen; Fibrinogens, Abnormal; Fibrinopeptide A; Fibrinopeptide B; Humans; Male; Pedigree; Platelet Aggregation; Thrombin; Thrombophlebitis; Thrombosis

A functionally abnormal fibrinogen was detected in a 27-year-old woman with no prior history of bleeding. Investigation of the defect revealed abnormal release of fibrinopeptide A and incomplete polymerization of fibrin monomers. Crosslinking of polymerized fibrin by Factor XIII was normal. To further characterize the dysfibrinogen, the increase in mechanical impedance during clot development was measured. Fibrinogen Seattle II showed several differences from normal fibrinogen: delayed onset of clotting, decreased rate of clot formation, and lower final clot impedance. Taken cumulatively, these data are consistent with an amino acid substitution at or near residue 16 in one of the A alpha chains, the point at which thrombin cleaves.

Topics: Adult; Blood Coagulation; Blood Coagulation Disorders; Factor XIII; Female; Fibrin; Fibrinogen; Fibrinogens, Abnormal; Fibrinopeptide A; Humans

A congenital dysfibrinogenemia was found in a 32-year-old asymptomatic female and her immediate family. The propositus, apparently a heterozygote for the abnormality, characteristically showed defective release of fibrinopeptide A from half of her fibrinogen molecules. No fibrinopeptide A was cleaved off from the isolated abnormal molecule by thrombin or snake venoms (Reptilase and Ancrod) as evidenced by radioimmunoassay, high performance liquid chromatography and determination of the NH2-terminal amino acids. The abnormal fibrinogen formed a solid gel solely by the release of fibrinopeptide B upon incubation with thrombin. We provisionally designate this abnormal fibrinogen as "Fibrinogen Kawaguchi", although possible identity with other abnormal fibrinogens is not excluded.

Topics: Adult; Amino Acid Sequence; Blood Coagulation Disorders; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinogens, Abnormal; Fibrinopeptide A; Hemostasis; Humans; Pedigree; Thrombin Time

An abnormal fibrinogen, denoted as "fibrinogen Bergamo I", has been characterized. Its defect consists in an exchange of arginine by cysteine in position 16 of the A alpha-chain, thus corresponding to that found in a number of other fibrinogen variants. The abnormal fibrinopeptide A cannot be split off by thrombin from intact fibrinogen Bergamo I. We describe three different chemical modifications of the cysteine A alpha 16, i.e. aminoethylation, methylation and carboxamidomethylation, and their effects on the susceptibility of fibrinogen Bergamo I towards thrombin attack. S-aminoethylation of the A alpha 16Cys renders the peptide bond A alpha 16-17 cleavable by thrombin. Following methylation or carboxamidomethylation, the A alpha 19-arginyl bond becomes accessible for thrombin. The chemically modified extended fibrinopeptide A can be readily separated from the normal fibrinopeptide A by HPLC. The latter two modifications are suitable alternative procedures for detecting the molecular defect A alpha 16Arg----Cys of fibrinogen.

Topics: Amino Acids; Aziridines; Blood Coagulation Disorders; Blood Coagulation Tests; Cysteine; Female; Fibrinogen; Fibrinogens, Abnormal; Fibrinopeptide A; Fibrinopeptide B; Humans; Male; Mercaptoethanol; Methylation; Thrombin

Topics: Adult; Anticoagulants; Antineoplastic Combined Chemotherapy Protocols; Blood Coagulation Disorders; Female; Fibrinogen; Fibrinopeptide A; Humans; Male; Middle Aged; Neoplasms

Topics: Blood Coagulation Disorders; Fibrin; Fibrinogen; Fibrinopeptide A; Fibrinopeptide B; Humans; Polymers; Prothrombin Time; United States; Wound Healing

A qualitative abnormality of fibrinogen was identified in a 40-year-old woman with recurrent thrombophlebitis. Fibrinogen levels were normal when determined by immunologic, gravimetric, or nephelometric methods (200-390 mg/dl), but were diminished when tested by techniques based on the thrombin time (13 mg/dl). Asymptomatic family members, including both parents of the proposita, were less severely affected (mean fibrinogen level 100 mg/dl). The rate of fibrinopeptide release from purified fibrinogen was abnormally slow, whereas purified fibrin monomers polymerized at a normal rate. The abnormal fibrinogen was found to act as a competitive inhibitor of thrombin with an inhibitor constant (Ki) of 0.2 microM. This value was the same as the Michaelis constant (Km) of the normal thrombin-fibrinogen reaction, an observation consistent with an abnormality that retards fibrinopeptide release without affecting enzyme-substrate affinity.

Topics: Adult; Blood Coagulation Disorders; Female; Fibrinogen; Fibrinopeptide A; Humans; Immunoelectrophoresis; Kinetics; Pedigree

Fibrin deposition and platelet thrombus dimensions on subendothelium were studied in four groups of patients with coagulation factor deficiencies. Five patients with factor VIII deficiency (APTT 120 +/- 8 sec) and three patients with factor IX deficiency (APTT 125 +/- 11 sec) were severe bleeders, whereas four patients with factor XII deficiency and seven with factor XI deficiency were either asymptomatic or only mild bleeders despite APTT values of 439 +/- 49 and 153 +/- 13 sec, respectively. Everted segments of deendothelialized rabbit aorta were exposed at a shear rate of 650 sec(-1) for 5 and 10 min to directly sampled venous blood in an annular chamber. Blood coagulation was evaluated by measuring fibrin deposition (percent surface coverage) on the subendothelium and post-chamber fibrinopeptide A levels; platelet thrombus dimensions on the subendothelium were evaluated by determining the total thrombus volume per surface area (using an optical scanning technique) and the average height of the three tallest thrombi. Consistent differences were observed among the patient groups for both the 5-min and 10-min exposure times. The larger of the 5- and 10-min exposure-time values was used to calculate group averages. Fibrin deposition in normal subjects was 81% +/- 5% surface coverage, and post-chamber fibrinopeptide A values were 712 +/- 64 ng/ml. Markedly decreased fibrin deposition and fibrinopeptide A levels were observed in factor VIII deficiency (2% +/- 1% and 102 +/- 19 ng/ml) and factor IX deficiency (11% +/- 7% and 69 +/- 11 ng/ml). In contrast, significantly higher values were obtained in patients deficient in factor XI (33% +/- 5% and 201 +/- 57 ng/ml) and factor XII (66% +/- 12% and 306 +/- 72 ng/ml). Differences in thrombus dimensions were also observed. In normal subjects, the value for thrombus volume and average height of the tallest thrombi were 8.3 +/- 1.3 cu micron/sq micron and 145 +/- 11 micron, respectively, and in patients were as follows: FVIII, 2.7 +/- 0.6 and 71 +/- 7; FIX, 4.5 +/- 1.8 and 88 +/- 14; FXI, 11.8 +/- 1.9 and 125 +/- 10; and FXII, 7.9 +/- 3.1 and 130 +/- 25. Platelet thrombus dimensions were normal in a patient with fibrinogen deficiency, indicating that the smaller thrombi in factor VIII and factor IX deficiencies were probably due to impaired evolution of thrombin rather than diminished fibrin formation.(ABSTRACT TRUNCATED AT 400 WORDS)

Topics: Adolescent; Adult; Aged; Blood Coagulation Disorders; Blood Platelets; Endothelium; Factor XI Deficiency; Factor XII Deficiency; Female; Fibrin; Fibrinogen; Fibrinopeptide A; Hemophilia A; Hemophilia B; Humans; In Vitro Techniques; Male; Middle Aged; Partial Thromboplastin Time; Platelet Adhesiveness; Prothrombin Time; Thromboplastin

Topics: Antibodies; Aspirin; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Platelets; Cell Adhesion; Cell Communication; Cyclooxygenase Inhibitors; Disseminated Intravascular Coagulation; Epoprostenol; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinopeptide A; Humans; Indomethacin; Monocytes; Neoplasm Transplantation; Neoplasms; Syndrome; Thrombocytopenia; Thrombocytosis; Thromboembolism; Thromboplastin

Topics: Blood Coagulation Disorders; Disseminated Intravascular Coagulation; Factor XII; Factor XIII; Female; Fibrinogen; Fibrinopeptide A; Humans; Kallikreins; Kininogens; Kinins; Pregnancy; Pregnancy Complications, Hematologic; Prekallikrein

Fibrinogen Manchester is an abnormal fibrinogen with an impaired release of fibrinopeptide A (FPA) and a polymerization abnormality. In the accompanying article we have identified the amino acid substitution in fibrinogen Manchester as A alpha 16 Arg leads to His. When fibrinogen Manchester was digested with low thrombin concentrations approximately 40-50% of the total FPA content was release at a rate similar to FPA release from normal fibrinogen. The fibrin so formed exhibited an impaired polymerization of monomers. Digestion of fibrinogen Manchester with high concentrations of thrombin for prolonged times released the remaining FPA which had an abnormal retention time when studied by high performance liquid chromatography (HPLC). This fibrinopeptide has been shown previously to contain the A alpha 16 Arg leads to His substitution. fibrin resulting from this exhaustive digestion had normal polymerization of monomers. The normal and substituted FPAs were isolated by HPLC and compared in a double antibody competitive-binding assay for normal FPA. The immunological cross-reactivity of the abnormal peptide was reduced, so that approximately 5 times more abnormal peptide was required on a molar basis to displace labelled normal FPA. Normal intact fibrinogen was 10-fold less reactive (on a half molar basis) than free normal FPA and the crossreactivity of fibrinogen Manchester was measurably less than that of normal fibrinogen. It is concluded that immunological measurement alone of FPA released from abnormal fibrinogens may not give a complete description of the kinetics of peptide release if the amino acid substitution lies within the FPA sequence. The combination of radioimmunoassay and HPLC, however, provides a powerful analytical approach that should be useful in classifying and characterizing abnormal fibrinogens.

Topics: Blood Coagulation Disorders; Chromatography, High Pressure Liquid; Cross Reactions; Female; Fibrin; Fibrinogen; Fibrinogens, Abnormal; Fibrinopeptide A; Fibrinopeptide B; Humans; Male; Thrombin

Purified samples of fibrinogen Manchester, a congenital dysfibrinogenaemia with impaired fibrinopeptide A (FPA) release, were digested with thrombin. Amino acid sequencing of the fibrin showed that FPA had been completely released. High performance liquid chromatographic (HPLC) analysis of the clot supernatant showed the presence of a new peptide eluting ahead of the normal FPA. The amino acid composition and sequence of the new peptide established its identity as a variant of FPA containing histidine in position 16 instead of the usual arginine. The chromatograms from both siblings with the defect demonstrated that they were heterozygous for this clotting defect.

Topics: Amino Acid Sequence; Amino Acids; Blood Coagulation Disorders; Chromatography, High Pressure Liquid; Female; Fibrinogen; Fibrinogens, Abnormal; Fibrinopeptide A; Histidine; Humans; Male

A kinetic analysis was developed to determine the steady state kinetic parameter Kcat/KM for the thrombin-catalyzed release of FPA from abnormal and normal fibrinogen in mixtures of the two. Such mixtures are likely to comprise the fibrinogen of individuals with congenital dysfibrinogenemia. The analysis was used to characterize fibrinogen Grand Rapids a new congenital dysfibrinogenemia. It indicated that fibrinogen from affected individuals was composed of normal and abnormal fibrinogen in roughly equal amounts, and that the value of kcat/KM for the thrombin-catalyzed release of FPA from the fibrinogen variant was 77-fold lower than that for the release of FPA from the normal fibrinogen. In separate studies, fibrinogen Grand Rapids was found to exhibit a reduced clottability. Additionally, affected individuals appeared to have plasma fibrinogen concentrations which were about one-third the normal value.

Topics: Blood Coagulation Disorders; Child; Fibrinogen; Fibrinogens, Abnormal; Fibrinolysin; Fibrinopeptide A; Humans; Kinetics; Male; Michigan; Thrombin Time

In a 81 year old health woman, gross abnormalities of fibrin formation led to the discovery of an abnormal fibrinogen named fibrinogen Bondy. Clottability of purified fibrinogen Bondy was only 53% compared to 95-98% for normal fibrinogen. Functional studies revealed (i) delayed coagulation by thrombin and batroxobin (Reptilase), (ii) incomplete release of fibrino-peptides A and B, (iii) poor fibrin monomer aggregation, (iv) delayed fibrin proteolysis by plasmin. Electrophoretic mobility of fibrinogen Bondy, its three chains and the products of fibrin cross-linking, was normal. Fibrinogen NH2-terminal residues of fibrinogen Bondy were found to be normal. The presence of Ala, in addition to Gly and Tyr in the fibrin clot and its supernatant, showed that a part of fibrinogen molecules was not clotted, i.e. either copolymerised with fibrin or remaining in solutions. Gel filtration of the supernatant allowed the separation of both soluble complexes and fibrinogen. This fibrinogen population was shown to be unclottable by thrombin and to inhibit clotting of normal fibrinogen.

Topics: Aged; Blood Coagulation Disorders; Chemical Phenomena; Chemistry, Physical; Chromatography, Gel; Cross-Linking Reagents; Female; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinogens, Abnormal; Fibrinolysin; Fibrinopeptide A; Fibrinopeptide B; Humans; Thrombin Time

Topics: Aged; Batroxobin; Blood Coagulation Disorders; Cross-Linking Reagents; Factor VIII; Female; Fibrin; Fibrinolysin; Fibrinopeptide A; Humans; Hydrolysis; Male; Michigan; Pedigree; Polymers; Radioimmunoassay; Thrombin

Activation of blood coagulation, as characterized by the occurrence of disseminated intravascular coagulation, increased levels of plasma FPA, and the local deposition of fibrin, is common in both experimental animals and patients with malignant tumors. Many mechanisms have been proposed for the mediation of this response to tumors, including tumor-associated proteases, platelet adherence to tumors, surface activation of blood coagulation by tumor cells, and activation of coagulation by tissue factor derived from either tumor tissue or reactive leukocytes. We have investigated the hypothesis that MTF generation may contribute to increased fibrin generation in cancer patients. Plasma FPA levels and in vitro unstimulated MTF generation were measured simultaneously in samples obtained from 35 patients with lung cancer. FPA levels were significantly elevated in these patients as compared to a group of 20 normal volunteers (p = 0.03). Although unstimulated MTF generation showed considerable variability in both the patients and the normal volunteers, a high degree of correlation was observed between simultaneous levels of FPA and MTF regardless of whether MTF was expressed per cell (r = 0.83), per monocyte (r = 0.95), or per volume of peripheral blood (r = 0.96). MTF generation was also significantly decreased in a group of patients receiving sodium warfarin (p less than 0.001). These results suggest a potential role for MTF generation in the activation of blood coagulation in neoplasia and also suggest the possibility that inhibition of MTF generation by warfarin may be partially responsible for the decreased FPA values previously reported in anticoagulated cancer patients.

Topics: Aged; Blood Coagulation Disorders; Cells, Cultured; Fibrinopeptide A; Humans; Lung Neoplasms; Middle Aged; Mitogens; Monocytes; Reference Values; Warfarin

Routine testing on plasma from a patient due to undergo a coronary artery bypass graft operation revealed a prolonged thrombin clotting time associated with a normal plasma fibrinogen level when this was determined by a method not dependent upon the rate of fibrin formation. Fibrinogen purified from the patient's plasma by precipitation with beta-alanine also gave a prolonged thrombin time and this confirmed the presence of a dysfibrinogenaemia. Increasing calcium chloride concentration, addition of protamine sulphate and decreasing ionic strength all produced a partial correction of the clotting defect. Addition of normal plasma to patient's plasma failed to correct the prolonged thrombin clotting time and a pH dependence of the defect was also observed. Kinetic studies of fibrinopeptide release, using a specific radioimmunoassay, demonstrated no delay in the release of patient fibrinopeptide A. The functional defect was localized as an abnormality in the polymerization of fibrin monomers by studying fibrin monomers prepared and isolated from plasma and from purified fibrinogen solution. An electrophoretic examination of the patient's fibrinogen using both agarose and polyacrylamide gels failed to demonstrate any alteration in mobility or any structural defect associated with the polypeptide chains A alpha, B beta and gamma. All seven of the living siblings of the propositus and also his daughter showed no abnormality in any clotting assay. However, because the propositus did not suffer from liver disease it has been assumed that the abnormality is genetic in origin.

Topics: Adult; Blood Coagulation Disorders; Blood Coagulation Tests; Electrophoresis, Polyacrylamide Gel; Fibrin; Fibrinogen; Fibrinopeptide A; Humans; Hydrogen-Ion Concentration; Immunodiffusion; Immunoelectrophoresis; Macromolecular Substances; Male; Pedigree; Thrombin

Investigation of the family of a patient presenting with haematuria revealed seven cases in three generations showing a prolonged thrombin clotting time. A dysfibrinogenaemia was confirmed when purified fibrinogen from an affected member of the family was shown to also exhibit a prolonged thrombin clotting time. No molecular abnormality could be demonstrated using electrophoretic and immunological techniques. However, using a specific radioimmunoassay to fibrinopeptide A a major defect has been localized to a delay in the rate of release of this peptide by thrombin when the abnormal fibrinogen is converted to fibrin. This case of dysfibrinogenaemia has been tentatively designated fibrinogen Manchester.

Topics: Blood Coagulation Disorders; Blood Coagulation Tests; Electrophoresis, Polyacrylamide Gel; Female; Fibrinogen; Fibrinopeptide A; Humans; Male; Middle Aged; Pedigree; Thrombin Time

The kinetics of the thrombin-catalysed release of fibrino-peptides A and B from human fibrinogen have been investigated and a mechanism correlating the release of fibrinopeptides to fibrin formation is presented. The sequential release of fibrinopeptides results in sequential activation of two sets of polymerisation sites.

Topics: Binding Sites; Blood Coagulation; Blood Coagulation Disorders; Calcium; Fibrin; Fibrinogen; Fibrinopeptide A; Fibrinopeptide B; Humans; Kinetics; Macromolecular Substances; Protein Binding; Thrombin

Topics: Blood Coagulation Disorders; Disulfides; Factor XIII; Fibrinogen; Fibrinopeptide A; Fibrinopeptide B; Humans; Molecular Conformation; Peptide Chain Termination, Translational; Thrombin

Topics: Ancrod; Batroxobin; Blood Coagulation Disorders; Blood Coagulation Tests; Blood Protein Electrophoresis; Child; Endopeptidases; Female; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinopeptide A; Humans; Immunoelectrophoresis; Structure-Activity Relationship; Thrombin

A new case of congenital dysfibrinogenemia has been discovered in a 20 year old woman, who suffered from a severe postpartal hemorrhage after the delivery of her first child, followed by episodes of thrombosis. Coagulation studies reveal a prolongation of thrombin time, reptilase time was immeasurable. Thromboplastin time and partial thromboplastin time were slightly prolonged. Low fibrinogen levels were obtained by techniques, which depend on the coagulation velocity following addition of thrombin, while immunological procedures gave slightly diminished values of fibrinogen. Patients's fibrinogen had a moderate inhibitory effect on the fibrin formation in normal plasma. However, inhibitors of the fibrinogen-fibrin conversion could not be detected. Coagulation factors were normal, fibriolysis as well. The cause of the coagulation disorder was found to be a defect of the fibrinogen molecule, leading to an abnormal fibrin polmerization of patient's fibrin monomers. The release of the fibrinopeptides in the paperelectrophoresis was normal. The defect of the fibrinogen molecule did not protect from thrombotic complications. The same defect could be found in the lower scale in patient's father, 4 of her 7 brothers and sisters, and her son.

Topics: Adult; Blood Coagulation Disorders; Blood Coagulation Tests; Female; Fibrinogen; Fibrinolysis; Fibrinopeptide A; Fibrinopeptide B; Hemorrhagic Disorders; Humans

Fibrinogen has been purified from normal and dysfibrinogenemia Metz plasmas, and from normal and from the patient's platelets. There are differences in the pattern of disc polyacrylamide gel electrophoresis between normal plasma and normal platelet fibrinogens, but the migration of the A alpha chain is similar. The abnormality of the electrophoretic mobility of the A alpha chain of plasma fibrinogen from Metz dysfibrinogenemia is not found in platelet fibrinogen of this patient. This result clearly establishes that platelet fibrinogen is a different protein from plasma fibrinogen.

Topics: Adult; Alkylation; Blood Coagulation Disorders; Blood Platelets; Blood Protein Electrophoresis; Chemical Phenomena; Chemistry; Electrophoresis, Disc; Female; Fibrinogen; Fibrinopeptide A; Humans; Peptide Hydrolases; Plasma

Topics: Blood Coagulation Disorders; Chromatography, Gel; Electrophoresis, Polyacrylamide Gel; Fibrinogen; Fibrinopeptide A; Humans; Methylation; Molecular Weight; Oxidation-Reduction; Peptide Fragments