Soluble Fibrin In Plasma Research Articles

Plasma Soluble Fibrin Is Useful for the Diagnosis of Thrombotic Diseases

Soluble fibrin (SF) is a form of fibrinogen that is activated by thrombin and is considered to be useful for the diagnosis of the prethrombotic state or thrombosis. Plasma levels of fibrin-related markers (FRMs), such as SF, D-dimer, fibrinogen, and fibrin degradation prioduct (FDP) levels in critically ill patients, were examined for the diagnosis of disseminated intravascular coagulation (DIC), venous thromboembolism (VTE), peripheral arterial thromboembolism (PATE), acute myocardial infarction (AMI), and acute cerebral infarction (ACI). FRMs showed the usefulness in diagnosing DIC and VTE and the cutoff values of D-dimer, FDP, and SF for DIC were 7.2-7.8 μg/mL, 10.0 μg/mL, and 9.5 μg/mL, respectively. The cutoff values of D-dimer and FDP for VTE were similar to the 97.5th percentile values of healthy volunteers, while the cutoff value of SF was 6.9 μg/mL. In AMI and ACI, the cutoff values of D-dimer and FDP were lower than the 97.5 percentile values of healthy volunteers. A receiver operating characteristic analysis for all thrombosis cases showed that an adequate cutoff value in only SF among FRMs was higher than the confidence interval of healthy volunteers. Only SF had high sensitivity for thrombosis, as the FDP/SF ratio was markedly low for ACI, AMI and VTE. FRMs, especially D-dimer and FDP, were useful for diagnosing thrombosis with hyperfibrinolysis (e.g., DIC). As SF showed high sensitivity for predominantly thrombotic diseases, including arterial thrombosis, such as ACI and AMI, a high SF value suggests the possibility of an association with thrombosis. Finally, SF is the most useful marker for raising suspicion of an association with thrombosis, especially arterial thrombosis.

Coagulation markers in patients with coronary artery disease

Coronary Artery Disease (CAD) is a major public health problem all over the world, and although diagnostic and treatment approaches are improving, the majority of individuals who suffer CAD will not survive. Therefore, it is a clinical demand to find out new biomarkers for identification of CAD in the earlier stage. The purpose of this study was to determine whether qualitative and quantitative alterations of plasma Soluble Fibrin Monomer Complexes (SFMCs) are associated with cardiovascular events. Additionally, some other well-known biomarkers of hypercoagulation state, such as fibrinogen, and prothrombin were analyzed in plasma of patients with different coronary artery pathologies. We found that plasma SFMC concentrations were remarkably increased in all tested CAD groups. Moreover, the development of CAD was accompanied by the changes in both quantity and quality of SFMC composition compared to that of healthy subjects. Our results also demonstrated the elevated level of high molecular weight Vitamin K-Dependent Protein (VKDP) complexes in plasma of CAD patients, which could be used as a potential biomarker of hypercoagulation state. More studies are clearly needed to investigate whether SFMCs or abnormal forms of VKDPs affect cardiovascular events under CAD development and progression.

Changes in the blood coagulation system that determine postoperative complications in patients with non-tumor mechanical jaundice

The OBJECTIVE was to study the features of changes in the blood coagulation system that contribute to the development of postoperative complications in patients depending on the stage of non-tumor mechanical jaundice at admission.METHODS AND MATERIALS. A total of 537 patients with mechanical jaundice were examined and changes in the blood coagulation system were analyzed. Vascular-platelet hemostasis was characterized by the following tests: capillary resistance, the number of desquamated endothelial cells, the number of blood platelets. Plasma hemostasis was analyzed using activated partial thromboplastin time, plasma soluble fibrin level, thrombin time, prothrombin ratio, prothrombin index, and fibrinogen blood level. Then, XIIa-dependent fibrinolysis in the blood and the level of the fibrin D-dimer in the blood plasma were determined.RESULTS. It was found that in the first stage of mechanical jaundice, with cholestasis, there were no changes in blood coagulation system that go beyond the normal limits. In the second stage, during cytolysis of hepatocytes, hyperbilirubinemia and hypertransaminasemia contribute to the activation of platelet first, and then plasma hemostasis. In the third stage (cholangitis), the death of endotheliocytes increases and there is a deficiency of blood coagulation factors due to their consumption and increased fibrinolysis.CONCLUSION. In the stage of cholestasis in patients with non-tumors mechanical jaundice, the parameters of the coagulation system remain within the reference values. In the stage of cytolysis, as endotheliotoxicosis increases, platelet and plasma hemostasis begins to activate, which can lead to thrombosis and thromboembolism in vital organs. In the stage of cholangitis, further activation of plasma hemostasis causes hemorrhagic syndrome. The occurrence of the described disorders in blood coagulation system with the progression of MJ dictates the need to monitor the changes in the blood coagulation system and their correction for the prevention of intra-and postoperative complications.

A Prospective Multicenter Observational Study of Venous Thromboembolism after Gastric Cancer Surgery (SHISA-1601)

Introduction: This study aimed to clarify the frequency and risk factors of intercurrent venous thromboembolism (VTE) in patients undergoing major curative gastric cancer surgery. Methods: This prospective, multicenter, observational study included patients with gastric cancer who underwent radical gastrectomy at 5 hospitals between June 2016 and May 2018. Patients who were preoperatively administered anticoagulants were excluded. Results: A total of 126 patients were eligible to participate. VTE occurred within 9 days postoperatively in 5 cases (4.0%; 2 symptomatic and 3 asymptomatic). Postoperative day (POD) 1 plasma D-dimer and soluble fibrin (SF) levels were significantly higher in the VTE group than in the non-VTE group. Receiver-operating characteristic curve (ROC) analysis indicated a statistically significant ability of POD 1 D-dimer and SF levels to predict postoperative VTE development after gastrectomy; this finding was reflected by an area under the curve (AUC) of 0.97 (95% CI 0.92–1.0) and 0.87 (95% CI 0.74–1.0), respectively. Cutoff values of D-dimer (24.6 µg/mL) and SF (64.1 µg/mL) were determined. Intraoperative blood transfusion (odds ratio [OR] 7.86), POD 1 D-dimer ≥24.6 µg/mL (OR 17.35), and POD 1 SF ≥64.1 µg/mL (OR 19.5) were independent predictive factors for postoperative VTE (p < 0.05). Conclusion: VTE occurred in 4.0% patients (1.6% symptomatic and 2.4% asymptomatic) after gastric cancer surgery; however, with an early diagnosis and anticoagulant therapy, no patients experienced progression. Careful observation of patients with a high risk for VTE, including intraoperative blood transfusion and high POD 1 D-dimer or SF levels, would contribute to the early detection of VTE.

大腸癌周術期発症の肺血栓塞栓症診断に可溶性フィブリンモノマー複合体（SFMC）測定が有用であった1例

大腸癌周術期発症の肺血栓塞栓症診断に可溶性フィブリンモノマー複合体（SFMC）測定が有用であった1例

Postmortem diagnosis of shock conditions

Aim. Develop a method for postmortem diagnosis of shock conditions.&#x0D; Methods. Brood serum obtained from 72 dead bodies of people who died from different causes such as anaphylaxis, toxic shock, cardiovascular diseases, traumatic injury and thermal burns was examined. The level of fibrinogen fraction was performed by sulfite-alkaline method. Plasma soluble fibrin monomer complexes were identified by paracoagulation tests (ethanol and protamine sulfate tests).&#x0D; Results. The method of shock conditions postmortem diagnosis was determined, regardless of shock etiology. The lowest levels of fibrinogen fraction in cases of anaphylactic and toxic shock were 19.3 and 11.9 g/l, respectively, which is significantly higher compared to other groups. In cases of death due to acute burn, fibrinogen level was almost tenfold higher (p

Clinical usefulness of measuring prothrombin time and soluble fibrin levels in Japanese patients with atrial fibrillation receiving rivaroxaban

BackgroundRivaroxaban is currently used to prevent stroke in patients with atrial fibrillation. Measuring coagulation function may help clinicians to understand the effects of this drug and the associated risk of bleeding. Methods and resultsRivaroxaban was given to 136 patients with non-valvular atrial fibrillation. Mean age was 74.5±9.0 years (men: 63.2%) and mean CHADS2 score (±SD) was 1.8±1.2. Prothrombin times (PTs) and plasma soluble fibrin (SF) levels were examined in 84 out of 136 patients at baseline and at least 2 weeks thereafter. In 48 patients we were able to collect blood at exact times, namely just before and 3h after rivaroxaban administration, corresponding to the trough and peak concentrations. Mean peak PT in 48 patients was 17.1±3.6s and median peak SF level was 1.46μg/mL. Multiple regression analysis showed that female sex, high brain natriuretic peptide, and high dose were independent factors prolonging the peak PT. Patients with peak PTs ≥20s experienced significantly more bleeding events. Among 29 of 46 patients newly treated with rivaroxaban without any previous anticoagulant, we examined coagulation function at the exact trough and peak times. In 29 patients, peak PT was significantly more prolonged than the baseline or trough PT (p<0.001 for both), whereas trough PT was comparable to the baseline PT. In contrast, both trough and peak SF levels in these newly treated patients were significantly reduced than at baseline (p=0.003 and p<0.001, respectively). ConclusionsIn Japanese patients with non-valvular atrial fibrillation receiving rivaroxaban, a prolonged peak PT (≥20s) could indicate increased risk of bleeding, and both trough and peak SF levels were reduced relative to baseline. PT and SF are both valuable measures of coagulation status in patients receiving rivaroxaban, regardless of prior anticoagulant history.

New Combinational Assay Using Soluble Fibrin and D-Dimer Determinations: A Promising Strategy for Identifying Patients with Suspected Venous Thromboembolism

AimTo establish a new and reliable assay for quantification of the soluble fibrin (SF) in combination with that of D-dimer for early diagnosis of venous thromboembolism.Methods and SamplesThe SF assay is based on D-dimer generated after incubation of plasma with tissue-type plasminogen activator (t-PA). SF and standard D-dimer assays, run in blind, were used to test 119 untreated outpatients with clinically suspected deep-vein thrombosis (DVT, 49 patients) or pulmonary embolism (PE, 70 patients) consulting at the emergency unit of the hospital. Thromboses were confirmed by current imaging methods such as ultrasonography, scintigraphy, computed tomographic pulmonary angiography (CTPA) and ventilation/perfusion scan.ResultsSF assay was validated in 270 healthy volunteers [51.8% males; mean age years ± SD: 41±13; age range 19 to 65]. Among these normal plasmas, SF levels were ≤200 ng/mL in 97.8% of them, and 200–250 ng/mL in the remainder [26–46 years old; 50% males]. ROC curves were used to determine the SF cut-off value for plasma SF positivity, which was found to be 300 ng/mL. In patients with suspected venous thromboembolism, SF sensitivities for DVT and PE (92% and 94%, respectively) were comparable to those of D-dimer (96% and 94%), whereas SF specificities (86% and 95%) were higher than those of D-dimer (50% and 54%). Positive-predictive values for SF (89% and 94%) were again higher than those of D-dimer (70% and 65%) in DVT and PE. The amount of circulating SF normalized rapidly after anticoagulant therapy.ConclusionResults from this small group of patients suggest that the evaluation of plasma SF, in combination with that of D-dimer, represents a potentially useful tool for the early diagnosis of venous thromboembolism, provided that the patients have not been treated previously by anticoagulants.

Clinical usefulness of measurement of plasma soluble fibrin levels in critically ill patients

The soluble fibrin monomer fibrinogen complex (SF) is a complex coupling fibrin monomer and fibrinogen molecules. As the level of SF reflects the thrombin generation activity in plasma, we may estimate the early-activated state of blood coagulation by the measurement of SF. The aim of this study is to evaluate the clinical usefulness of SF for the hypercoagulated state.

Changes in soluble fibrin levels during the perioperative period of gynecologic cancer surgery

The purpose of this study was to evaluate the changes in plasma soluble fibrin (SF) levels over time in gynecologic cancer patients following surgery. Furthermore, we examined the duration of the coagulation stage and determined a suitable duration for which thromboprophylaxis with anticoagulant agents should be administered. We retrospectively studied 311 patients with invasive gynecologic cancer who underwent surgery at Okayama University Hospital, Japan. The plasma SF levels were measured serially prior to the operation and on postoperative days 0, 1, 3, 5, 7, 10, 14, 21 and 28. The plasma SF levels increased rapidly, peaked on postoperative day 1 and then decreased. The SF levels of patients with venous thromboembolism (VTE) were significantly different from those of VTE-negative patients on postoperative days 0-10. The SF levels on each day did not significantly differ between patients treated with chemical anticoagulants and those treated mechanically. The plasma SF levels were elevated (≥7.0 μg/ml) in 159 of the 311 patients (51.1%) on one of the days when these levels were measured. Among the patients with elevated plasma SF levels, 110 patients (69.2%) peaked on days 0-3 and only 9 patients (5.7%) peaked on days 21-28. Although only 1 of the 14 patients (7.1%) who showed peak levels on day 14 had undergone chemotherapy following surgery, 8 of the 9 patients (88.9%) whose levels peaked on days 21-28 had undergone chemotherapy following surgery (P= 0.0002). In conclusion, the plasma SF levels increased rapidly, peaked on postoperative day 1 and then decreased. These levels peaked within 14 days of surgery in most cases. Therefore, chemical thromboprophylaxis may be administered for at least up to 14 days following surgery.

Plasma Soluble Fibrin Monomer Complex as a Marker of Coronary Thrombotic Events in Patients with Acute Myocardial Infarction

Soluble fibrin monomer appears in the bloodstream during the extremely early stage of blood coagulation and generally forms a complex with fibrinogen, termed soluble fibrin monomer complex (FMC). Determination of FMC can provide information regarding the state of thrombotic diseases; thus it is important to investigate whether FMC serves as an early indicator of myocardial infarction (MI). We investigated hemostatic and fibrinolytic parameters including FMC to determine their capabilities for indicating thrombotic conditions in the coronary artery. Blood samples from 47 patients with acute MI were obtained within 48 hours (acute phase) and during 120 - 600 hours (recovery phase), respectively, after MI onset. Plasma FMC was significantly elevated in the acute phase, compared with that during the recovery phase and in healthy controls (p = 0.001), suggesting that its elevation indicates thrombotic events in the coronary artery of MI patients. D-dimer, a marker of thrombus formation accompanied with fibrinolysis, was increased in both phases in the patients. In addition, FMC and D-dimer were significantly increased within 24 hours after onset as compared to 24 - 48 hours (p = 0.003 and p = 0.011). Furthermore, cardiac troponin T, a marker of myocardial damage, was significantly higher after 24 hours than within the first 24 hours (p = 0.001). Receiver operating characteristic (ROC) analysis of FMC for early MI diagnosis indicates that FMC, rather than D-dimer, is a better marker within 24 hours of onset. Measuring plasma FMC may be useful for early diagnosis of MI recurrence and deciding primary treatment.

Elevation of circulating thrombin–antithrombin III complex and fibrin degradation products in urticaria: A laboratory finding unrelated to intravascular coagulopathy

Dear Editor, Voluminous exudation of plasma components into the dermis through the hyperpermeable cutaneous vasculature marks a pathophysiological feature of urticaria. When skin mast cells are stimulated to degranulate by injection of recombinant human stem cell factor, fibrin is shown to be deposited in the perivascular area at the injected sites.1 Fibrin formation, therefore, originating from extravasated plasma fibrinogen could likewise occur in urticarial skin lesion. Massive fibrin formation in the dermis may well affect the plasma levels of coagulation/fibrinolysis parameters. As shown in Table 1, a large proportion of urticaria patients showed elevated circulating thrombin–antithrombin III complex (TAT) and/or D-dimer. Nobody showed a drop in plasma antithrombin III (AT III) activity, or a detectable level of plasma soluble fibrin monomer complex (SFMC). All the patients showed normal levels or ranges of platelet counts, prothrombin time (PT), activated partial thromboplastin time (APTT), plasma protein C and S activities, serum compliment C3 and C4, plasma fibrinogen and prothrombin (Factor II). The extent of skin rash was roughly correlated with circulating TAT or D-dimer. Some moderate and severe urticaria patients showed plasma levels of TAT and/or D-dimer comparable to those seen in thromboembolic disorders (TAT, >10 ng/mL; D-dimer, >10 µg/mL). Patients with higher plasma TAT levels tended to have higher D-dimer levels, but there was apparent disproportion between the two values in some cases. After the subsidence of urticaria, the elevated TAT levels returned within the normal range in all cases, so did the elevated D-dimer levels in all cases but two. In contrast, none of eight non-pruritic plaque psoriasis patients in stable clinical courses showed the elevation (data not shown). All the urticaria patients recovered without any sequel, not to mention thromboembolic complications. The observation suggests that the transient elevation of circulating D-dimer and/or TAT is relevant to skin mast cell degranulation, and that thrombin generation and subsequent activation of coagulation/fibrinolysis cascade occur in urticaria. The absence of signs and symptoms of intravascular coagulation in addition to the normal laboratory data including platelet counts, PT, APTT, plasma fibrinogen and prothrombin levels, and AT III activities indicates that activation of coagulation/fibrinolysis cascade occurs extravascularly, as demonstrated by abundant fibrinogen deposit in the dermis of biopsy specimens from urticaria (Fig. 1). Once the plasma coagulation factors extravasate into the dermis, coagulation/fibrinolysis cascade is instantly activated. Thrombin is inactivated by tissue AT III, thus not affecting plasma AT III activity. The TAT and fibrin degradation products then flow backwards into the systemic circulation through the hyperpermeable vasculature. Therefore, plasma TAT and/or D-dimer elevation should not be mistaken for evidence of impending or ongoing intravascular coagulopathy in urticaria. The absence of circulating SFMC, a sensitive indicator of fibrinolysis, is also accountable when fibrinolysis proceeds at the extravascular locus. The much larger Mr of SFMC than that of TAT or D-dimer prevents the molecule from reentering the circulation. There is a remote possibility that the normal constituents of the skin, including epidermal keratinocytes,2 eccrine duct epithelial cells or vascular endothelial cells,3 may be the source of thrombin under certain inflammatory conditions, triggering the activation of coagulation cascade in the skin. Thrombin and fibrin degradation products have such pleiotropic immunomodulatory or pro-inflammatory properties as enhancement of vascular permeability and provocation of mast cell degranulation.4,5 Whatever the mechanism of elevated circulating TAT and D-dimer might be, our observation suggests a potential role of coagulation/fibrinolysis cascade activation in the skin in mast cell-mediated inflammatory dermatoses, as implicated by the report of effective anticoagulation therapy for recalcitrant urticaria.6 Fibrinogen deposit in the dermis of biopsy specimens from (a) the lesional skin of psoriasis (b) and urticaria (case 3). Paraffin-embedded biopsy specimens were deparaffinized and incubated with polyclonal anti-fibrinogen antibody (DAKO Japan, Kyoto, Japan). Color development was achieved using diaminobenzidine as substrate (original magnification, ×40). Note the abundant fibrinogen deposit in the perivascular and interstitial areas in the dermis of urticarial skin. The immunohistochemical staining of the biopsy specimens from three psoriasis and four urticaria patients showed similar findings.

Diagnosis of deep vein thrombosis by plasma-soluble fibrin or D-dimer

The present study was designed to determine the cutoff values of D-dimer and soluble fibrin (SF) for the diagnosis of deep venous thrombosis (DVT) and pulmonary embolism (PE) in Japanese patients. Plasma levels of these molecules were measured in 243 patients suspected of having DVT and 100 healthy volunteers (controls). Out of 243 patients, 20 patients were diagnosed with DVT. In the control group, plasma levels of D-dimer and SF did not show normal distribution, and the 95% confidence intervals (CI) of D-dimer and SF were 2.45 microg/mL and 6.92 microg/mL, respectively. Plasma levels of D-dimer and SF of patients with DVT were significantly higher than of those without DVT. In patients with DVT, the minimum values of D-dimer and SF were 1.71 and 1.44 microg/mL, respectively. When the cutoff value was set at the average+1 SD of those of the control (D-dimer, about 1.8 microg/mL; SF, about 1.4 microg/mL), 1 and 0 patient with DVT was overlooked, respectively. The sensitivity and specificity of D-dimer and SF for DVT were 95% and 100%, and 61.9% and 53.8%, respectively. When the cutoff value was set at 95% CI of the control (D-dimer, 2.5 microg/mL; SF, 6.9 microg/mL), 2 and 9 patients with DVT were overlooked, respectively. The sensitivity and specificity of D-dimer and SF were 90% and 50%, and 77.6% and 88.3%, respectively. When the cutoff values set at 2.5 microg/mL of D-dimer or 6.9 microg/mL of SF, 1 DVT patient was overlooked, with sensitivity and specificity of 95% and 69.5%. Our data suggest that both D-dimer and SF are useful markers for the diagnosis of DVT and that measurement of both D-dimer and SF increases the sensitivity and specificity for the diagnosis of DVT/PE.

Soluble fibrin augments spreading of fibroblasts by providing RGD sequences of fibrinogen in soluble fibrin

We previously reported that fibroblasts were found to spread far more avidly on NaBr-solubilized fibrin monomer (FM) monolayers than on immobilized fibrinogen (Fbg), indicating that removal of fibrinopeptides by thrombin is a prerequisite for the fibrin-mediated augmentation of cell spreading [J. Biol. Chem. 272 (1997) 8824–8829]. Soluble fibrin (SF), a 1:2 complex of fibrin-monomer and fibrinogen, is known to be present in the circulating blood under the pathological condition in which blood coagulation is activated. However, its physiological roles are still incompletely known. Fibroblasts spread on immobilized purified soluble fibrin. Cells spreading on immobilized soluble fibrin were blocked by the exogenous addition of soluble fibrin and glycine–arginine–glycine–aspartic acid–serine–phenylalanine (GRGDSP)-synthetic peptide but not by the addition of fibrinogen or fibrin monomer. However, cell spreading activity was decreased in the surfaces coated with fragment X, whose Aα-chains lack carboxyl-terminal segments including arginine–glycine–aspartic acid (RGD)-2 domain, fibrin monomer complexes. It suggests that the RGD-2 domain of fibrinogen after being complexed with fibrin monomer plays a pivotal role for soluble fibrin-dependent cell spreading. Soluble fibrin in plasma derived from the patients of disseminated intravascular coagulation (DIC) was immuno-purified using the monoclonal antibody (mAb) which specifically recognizes the Ca ++-dependent conformer of fibrinogen. The purified soluble fibrin consisted of desAA-fibrin monomer and two fibrinogen molecules and did show the cell spreading activity. Thus, soluble fibrin in plasma plays a role as the modulator of thrombogenic process in vivo.

Increased soluble fibrin in plasma of patients with disseminated intravascular coagulation.

Plasma levels of soluble fibrin (SF) were measured in 1184 patients with disseminated intravascular coagulation (DIC) according to Japanese Ministry of Health and Welfare (JMHW) criteria. The usefulness of SF for the diagnosis of DIC was compared with other hemostatic molecular markers. Most hemostatic markers were significantly increased in patients with DIC than in those without DIC. Plasma levels of fibrin and fibrinogen degradation products, thrombin-antihtrombin complex, plasmin-plasmin inhibitor complex, D-dimer, thrombomodulin, and SF levels were also significantly higher in those with pre-DIC than in those without DIC. In classification of overt DIC by International Society of Thrombosis and Haemostasis (ISTH) criteria, most hemostatic markers were significantly increased in patients with overt DIC than in those without overt DIC. Plasma levels of SF 'in patients with DIC were significantly higher than those in patients with pre-DIC, which were significantly higher than in those without DIC. Plasma levels of SF were also significantly higher in patients with overt DIC than in those with non-overt DIC. The correlation between plasma SF levels and DIC score according to JMHW criteria or ISTH criteria was good. Receiver operating characteristic analysis shows that SF was the best marker for the diagnosis of DIC or overt DIC. These findings suggest that plasma SF might be useful marker for the diagnosis of DIC or overt DIC.

A novel monoclonal antibody to fibrin monomer and soluble fibrin for the detection of soluble fibrin in plasma

Background: Soluble fibrin (SF), composed of fibrin monomer (FM) and fibrinogen, is well known to exist in the circulating blood derived from patients with thrombotic diseases, and its quantification is useful to get some information on the state and degree of intravascular coagulation. However, there was no convenient method for the determination of SF. Methods: We prepared a novel monoclonal antibody (MoAb) (F405) to FM and SF using desAA-fibrin as the immunogen in the presence of anti-polymerant peptide (Gly-Pro-Arg-Pro, GPRP), and the characterization of the F405 was performed by Western blotting analysis and an enzyme-linked immunosorbent assay (ELISA). We also tried to detect SF in human plasma using an ELISA involving the immobilized F405 and horseradish peroxidase (POD)-labeled anti-fibrinogen polyclonal antibody. Results: The antibody reacted with the fibrin degradation products fragments X, Y and E, but not with fibrinogen or its fragments X, Y, D and E, or the fibrin D-dimer. The epitope recognized by F405 appeared to be the α-chain N-terminal region exposed upon removal of the A peptide from the Aα-chain because F405 was found to bind to the α-chain N-terminal oligo-peptide of fibrin (GPRVVERHQ). Since F405 reacted not only with FM in the presence of GPRP peptide, but also with the SF complex prepared by the addition of thrombin-treated FM to human fibrinogen, we attempted to detect SF in human plasma using ELISA. The analytical range of this method was 1–300 μg/ml. The assay detection limit was <0.5 μg/ml, and the results of intra- and inter-assay precision studies indicated that this method is accurate and yields reproducible results (<9.4% and <10%, respectively). When 56 samples of plasma from patients with disseminated intravascular coagulation (DIC) and 117 control samples from healthy individuals were tested, elevated levels of SF complex were detected in the DIC samples: the mean±S.D. of the SF concentration in the DIC and control samples were 63.4±65.3 μg/ml and 1.9±1.0 μg/ml, respectively. Conclusions: The ELISA using F405 is useful for the diagnosis of DIC.

Impact of the fibrinolytic enzyme system on prognosis and survival associated with non-small cell lung carcinoma.

Comprehensive studies of fibrinolysis in non-small cell lung carcinoma have been limited, and assignment of patients to high/low prognosis groups based on arbitrary cut-offs utilizing fibrinolytic measurements is unstandardized. This study was performed in 166 patients to examine the effects of cut-off values determined in three ways. Model 1 assigned patients to one of three equal groups (low, medium, high) based on fibrinolytic measurements made at diagnosis, Model 2 divided patients into low/high groups using median values, and Model 3 grouped according to the parameter being above/below normal range. In model 1, raised plasma fibrinogen, D-dimer and soluble fibrin were positively associated with poorer survival. In model 2, tissue plasminogen activator antigen was additionally related to poorer prognosis. Model 3 identified seven parameters as significantly related to survival, two not identified by the other models becoming significant [plasmin-antiplasmin, tissue plasminogen activator inhibitor-1 (PAI-1) antigen]. Using multivariate analysis, plasma fibrinogen level was the most uniformly significant parameter. Relative risk estimates indicated that raised plasma fibrinogen, soluble fibrin and D-dimer were associated with increased risk of death. Use of the normal/above normal cut-off is recommended to provide the maximum number of significant parameters relating to prognosis, and increased plasma D-dimer, PAI-1 antigen and fibrinogen were most closely related to survival/prognosis.

Analysis of fibrin formation and proteolysis during intravenous administration of ancrod

AbstractAncrod is a purified fraction of venom from the Malayan pit viper, Calloselasma rhodostoma, currently under investigation for treatment of acute ischemic stroke. Treatment with ancrod leads to fibrinogen depletion. The present study investigated the mechanisms leading to the reduction of plasma fibrinogen concentration. Twelve healthy volunteers received an intravenous infusion of 0.17 U/kg body weight of ancrod for 6 hours. Blood samples were drawn and analyzed before and at various time points until 72 hours after start of infusion. Ancrod releases fibrinopeptide A from fibrinogen, leading to the formation of desAA-fibrin monomer. In addition, a considerable proportion of desA-profibrin is formed. Production of desA-profibrin is highest at low concentrations of ancrod, whereas desA-profibrin is rapidly converted to desAA-fibrin at higher concentrations of ancrod. Both desA-profibrin and desAA-fibrin monomers form fibrin complexes. A certain proportion of complexes carries exposed fibrin polymerization sites EA, indicating that the terminal component of the protofibril is a desAA-fibrin monomer unit. Soluble fibrin complexes potentiate tissue-type plasminogen activator-induced plasminogen activation. Significant amounts of plasmin are formed when soluble fibrin in plasma reaches a threshold concentration, leading to the proteolytic degradation of fibrinogen and fibrin. In the present setting, high concentrations of soluble fibrin are detected after 1 hour of ancrod infusion, whereas a rise in fibrinogen and fibrin degradation products, and plasmin-α2–plasmin inhibitor complex levels is first detected after 2 hours of ancrod infusion. Ancrod treatment also results in the appearance of cross-inked fibrin degradation productd-dimer in plasma.

Analysis of fibrin formation and proteolysis during intravenous administration of ancrod

Ancrod is a purified fraction of venom from the Malayan pit viper, Calloselasma rhodostoma, currently under investigation for treatment of acute ischemic stroke. Treatment with ancrod leads to fibrinogen depletion. The present study investigated the mechanisms leading to the reduction of plasma fibrinogen concentration. Twelve healthy volunteers received an intravenous infusion of 0.17 U/kg body weight of ancrod for 6 hours. Blood samples were drawn and analyzed before and at various time points until 72 hours after start of infusion. Ancrod releases fibrinopeptide A from fibrinogen, leading to the formation of desAA-fibrin monomer. In addition, a considerable proportion of desA-profibrin is formed. Production of desA-profibrin is highest at low concentrations of ancrod, whereas desA-profibrin is rapidly converted to desAA-fibrin at higher concentrations of ancrod. Both desA-profibrin and desAA-fibrin monomers form fibrin complexes. A certain proportion of complexes carries exposed fibrin polymerization sites E(A), indicating that the terminal component of the protofibril is a desAA-fibrin monomer unit. Soluble fibrin complexes potentiate tissue-type plasminogen activator-induced plasminogen activation. Significant amounts of plasmin are formed when soluble fibrin in plasma reaches a threshold concentration, leading to the proteolytic degradation of fibrinogen and fibrin. In the present setting, high concentrations of soluble fibrin are detected after 1 hour of ancrod infusion, whereas a rise in fibrinogen and fibrin degradation products, and plasmin-alpha(2)-plasmin inhibitor complex levels is first detected after 2 hours of ancrod infusion. Ancrod treatment also results in the appearance of cross-inked fibrin degradation product D-dimer in plasma. (Blood. 2000;96:2793-2802)

Failure of soluble fibrin polymers in the diagnosis of clinically suspected deep venous thrombosis.

A new diagnostic test has recently become available which is highly specific for plasma soluble fibrin polymers, the thrombus precursor protein (TpP) enzyme immunoassay. In order to evaluate the diagnostic accuracy of this test and that of a new rapid and automated test for the determination of D-dimers, the BC D-dimer test, in patients with clinically suspected deep vein thrombosis (DVT), 70 consecutive symptomatic patients underwent laboratory analysis with both tests and with the classic enzyme-linked immunosorbent assay (ELISA) D-dimer test, followed by the execution of a compression ultrasound (CUS) test of the affected limb. Patients with a positive CUS test were considered to have DVT (20 of 70), whereas those with a serially negative test and an uneventful 3-month follow-up test were regarded as not having DVT (50 of 70). The sensitivity of the TpP test (45.0%) was significantly lower than that of both the BC D-dimer test (80.0%; P = 0.02) and the classic ELISA test (90.0%; P = 0.002). The specificity of the TpP test (66.0%) did not differ from that of either D-dimer test (60.0 and 64.0%, respectively). The negative predictive value of the TpP test (75.0%) was significantly lower than that of the classic ELISA D-dimer test (94.1%; P = 0.02), which in turn did not differ from that of the BC D-dimer test (88.2%). The positive predictive value was similarly low for each investigated test (34.6, 44.4, and 50.0%, respectively). In conclusion, the TpP test can neither be used to detect a DVT nor to exclude its development in patients with the clinical suspicion of this disease. By contrast, the BC D-dimer might safely replace the classic ELISA test for excluding DVT in symptomatic patients.