Serum Fibrin-fibrinogen Degradation Products Research Articles

The relationship between serum coagulation parameters and the recurrence of chronic subdural hematoma.

The aim is to investigate the relationship between serum coagulation parameters (PT, APTT, D-D and FDP) before hospitalization and recurrence of chronic subdural hematoma (CSDH). 236 patients with CSDH who were diagnosed for the first time and had complete medical records were followed up for at least 90days. Fifty patients (21.2%) had relapsed. Univariate analysis was conducted including general data, imaging data and test results. Serum coagulation parameters (PT, APTT, D-D and FDP) were detected for all CSDH patients. The study identified several factors that exhibited a significant correlation with chronic subdural hematoma (CSDH) recurrence. These factors included advanced age (p = 0.01), hypertension (p = 0.04), liver disease (p = 0.01), anticoagulant drug use (p = 0.01), antiplatelet drug use (p = 0.02), bilateral hematoma (p = 0.02), and single-layer hematoma (p = 0.01). In addition, the presence of fibrin/fibrinogen degradation products (FDP) exceeding 5mg/L demonstrated a significant relationship with CSDH recurrence (P < 0.05). Notably, the combined assessment of D-dimer (D-D) and FDP exhibited a significant difference, particularly regarding recurrence within 30days after surgery (P < 0.05). The simultaneous elevation of serum FDP and D-D levels upon admission represents a potentially novel predictor for CSDH recurrence. This finding is particularly relevant for patients who experience recurrence within 30days following surgical intervention. Older individuals with CSDH who undergo trepanation and drainage should be closely monitored due to their relatively higher recurrence rate.

Hemostatic findings of pleural fluid in dogs and the association between pleural effusions and primary hyperfibrino(geno)lysis: A cohort study of 99 dogs.

The primary objective of this study was to determine if activation of coagulation and fibrinolysis occurs in canine pleural effusions. Thirty-three dogs with pleural effusions of different origin were studied. Pleural effusion fibrinogen concentrations were significantly lower, while pleural fibrin-fibrinogen degradation products (FDPs) and D-dimer concentrations were significantly higher than those in plasma (P < 0.001 for all comparisons). These results show that, in canine pleural fluids, there is evidence of coagulation activation and fibrinolysis. The secondary aims of the current study were to determine if primary hyperfibrinolysis ([PHF] i.e., elevated plasma FDPs with a normal D-dimer concentrations), occurs in dogs with pleural effusion, and whether the presence of a concurrent inflammatory process may have activated the hemostatic cascade, with its intrinsically linked secondary hyperfibrinolysis, masking the concurrent PHF. The previously 33 selected dogs with pleural effusion (group 1) were compared to two control groups of 33 healthy (group 2) and 33 sick dogs without pleural effusion (group 3). Serum fibrinogen, FDPs, D-dimer, C-reactive protein (CRP), fibrinogen/CRP ratio, and frequency of PHF were determined. Fibrinogen, FDPs, D-dimer and CRP concentrations in group 1 were significantly increased compared to group 2 (P < 0.001 for all comparisons). FDPs and CRP concentrations in group 1 were also significantly increased compared to group 3 (P = 0.001 and P < 0.001, respectively). The fibrinogen/CRP ratio was significantly decreased in group 1 compared to groups 2 and 3 (P < 0.001 for both comparison). The frequency of PHF was significantly higher in group 1 compared to groups 2 (P = 0.004), but not compared to group 3. These results support the hypothesis that PHF occurs significantly more often in dogs with pleural effusion compared to healthy dogs. Nevertheless, the decrease in the fibrinogen/CRP ratio in group 1 compared to group 3, considering the higher FDPs and similar D-dimer concentrations, would suggest that PHF is also more frequent in dogs with pleural effusion compared to sick control dogs, and that this phenomenon is hidden due to concurrent secondary hyperfibrinolysis.

Comparison of the serum fibrin-fibrinogen degradation products with cytokeratin 19 fragment as biomarkers in patients with lung cancer.

Lung cancer is one of the main causes of cancer-related mortality. The identification of early diagnostic biomarkers improved outcomes for lung cancer patients. Serum fibrin-fibrinogen degradation products (FDP) levels are elevated in numerous malignancies due to hemostatic alterations. The serum FDP levels were compared to the levels of cytokeratin 19 fragment antigen (CYFRA 21-1), another well-established biomarker. The serum samples from 193 lung cancer patients, 84 healthy controls and 106 patients with benign respiratory diseases were obtained. The serum FDP level was measured using the DR-70 immunoassay and the CYFRA 21-1 level was measured by electrochemiluminescence using the Roche Analytics E170. Receiver operating characteristics curves were used to assess the predictive sensitivity and specificity. The mean serum FDP level in lung cancer patients (35.01±229.02 μg/ml) was significantly higher compared to the 190 non-cancerous subjects (0.60±0.75 μg/ml; P=0.039). The mean serum CYFRA 21-1 level in lung cancer patients (4.50±6.67 ng/ml) was also significantly higher compared to the non-cancerous subjects (1.40±0.83 ng/ml; P<0.05). FDP exhibited clinical sensitivity and specificity of 86 and 75%, respectively, at an optimal cut-off at 0.67 μg/ml. CYFRA 21-1 exhibited clinical sensitivity and specificity of 77 and 74%, respectively, at a cut-off of 1.65 ng/ml. The serum FDP area under the curve (0.87) was slightly higher compared to CYFRA 21-1 (0.83). Therefore, it is apparent that serum FDP is comparable to CYFRA 21-1 as a lung cancer biomarker and can be used for clinical practice.

Comparison of Serum Fibrin-Fibrinogen Degradation Products with Carcinoembryonic Antigen as Biomarkers for Colon Cancer

Comparison of Serum Fibrin-Fibrinogen Degradation Products with Carcinoembryonic Antigen as Biomarkers for Colon Cancer

Measurement of urinary fibrin/fibrinogen degradation products by latex photometric immunoassay.

Intraglomerular coagulation and fibrinolysis could be involved in the exacerbation of renal diseases, and urinary fibrin/fibrinogen degradation products (FDP) may be applicable as an index. Although the urinary FDP can be estimated by the latex agglutination method, this technique has disadvantages such as a poor sensitivity and is of the semiassay type. Recently, a new method of measurement which improves on these disadvantages, termed the latex photometric immunoassay (LPIA) method, has been developed. However, since FDP measurement by LPIA was designed for the purpose of serum FDP estimation, a measurement technique for urinary FDP has not yet been established. The purpose of the present study was to devise a measurement procedure for urinary FDP employing the LPIA method, and to obtain data on the normal levels of urinary FDP in healthy subjects. The results obtained may be summarized as follows. (1) The urinary pH and coexistent substances such as bovine serum albumin, glucose, urea, bilirubin, ascorbic acid, and hemoglobin, did not influence the urinary FDP measurement. (2) No changes in urinary FDP were observed after 28-day storage at -20 degrees C or -80 degrees C in the presence or absence of tranexamic acid. (3) The coefficient of variation was 5.3%. (4) The normal level of FDP excretion was 3.33 +/- 7.95 micrograms/day. The present data demonstrated that the LPIA method enables the urinary FDP to be measured quantitatively with a good sensitivity.

Elevated Fibrinogen‐Fibrin Degradation Products (FDP) in Serum of Colorectal Cancer Patients

Serum fibrinogen‐fibrin degradation product (FDP) levels of healthy control subjects and of patients with colorectal cancer have been measured by DR‐70® ELISA in Frankfurt, Germany (Germany study) and in Tustin, California (U.S. study). Serum FDP levels of patients with colorectal cancer were significantly higher than those of the healthy controls. The median serum FDP levels in healthy control groups of the German and U.S. studies were, respectively, 0.37 µg/mL and 0.61 µg/mL. The median serum FDP levels in the colorectal cancer groups of the German and U.S. studies were, respectively, 1.25 µg/mL and 1.60 µg/mL. The results are consistent with enhanced fibrinolysis in serum of patients with colorectal cancer.

The history of acute promyelocytic leukaemia.

The history of acute promyelocytic leukaemia.

Thrombolytic Versus Fibrinogenolytic Activity of rt-PA and Streptokinase in Patients with Acute Myocardial Infarction

In this study the concentration of plasma breakdown products of cross-linked fibrin (XDP), serum fibrinogen-fibrin degradation products (FDP), and plasma fibrinogen were measured before and at the end of the administration of single-chain recombinant tissue-type plasminogen activator (rt-PA, 100 mg IV over three hours) or streptokinase (1.5 million units over one hour), respectively, in two groups, each composed of 22 patients with acute myocardial infarction. The XDP concentration was not statistically different between the two groups at the end of thrombolytic treatment, whereas FDP and fibrinogen concentrations were significantly different (FDP: streptokinase 396 +/- 287 vs rt-PA 177 +/- 222 micrograms/mL, p less than 0.01; fibrinogen: streptokinase 71 +/- 43 vs rt-PA 181 +/- 49 mg/dL, p less than 0.001). These results indicate that the two drugs have equipotent thrombolytic activity at this administration regimen but that rt-PA causes a markedly more selective lysis of fibrin in comparison with streptokinase.

Role of D Dimer in Patients with Elevated Fibrinogen Degradation Products in Serum: Further Study in Chronic Myelogenous Leukemia

We quantitatively assayed the levels of cross-linked fibrin degradation products (D dimer) in plasma at 73 points in time in 32 patients with elevated fibrin/fibrinogen degradation products (FDP) in serum. The assay of FDP was performed on serum samples prepared in test tubes containing 5 U/ml thrombin (final concentration) by a method based on latex agglutination using antifibrinogen antibodies, and the levels of D dimer in plasma were determined by a newly developed latex immunoassay using monoclonal antibodies which do not cross-react with fibrinogen. 5 patients with chronic myelogenous leukemia (CML) had highly elevated FDP levels with normal levels of D dimer. Plasma samples from such patients with CML were treated with various concentrations of thrombin (2-10 U/ml) and after the removal of fibrin clots the levels of FDP in supernatants were assayed by the FDP assay procedure described above. The levels of FDP were normalized when plasma were treated with 10 U/ml thrombin. In 2 patients with CML who had elevated levels of FDP in serum, it was impossible to remove fibrinogen completely by addition of 5 U/ml thrombin. However, FDP levels in the sera treated with 5 U/ml thrombin were almost normal in normal controls and patients with other diseases than CML. From these results it is concluded that residual fibrinogen reacted in the assay procedure as markedly increased FDP in supernatants and elevated FDP levels in serum reflected fibrinogen-related materials, which may not completely polymerize in the presence of lower concentrations of thrombin in some patients with CML. The assay of D dimer in plasma using monoclonal antibodies is recommended in cases of CML to rule out disseminated intravascular coagulation.

Haemostatic abnormalities in horses with colic--their prognostic value.

The incidence and nature of coagulation abnormalities in horses presented with colic and the possible prognostic value of these abnormalities was investigated. A coagulogram was performed on each of 24 adult Thoroughbred or Standardbred horses. A coagulogram consisted of measurements of eight parameters; platelet count, plasma fibrinogen, plasma antithrombin III (AT), partial thromboplastin time (PTT), prothrombin time (PT), thrombin clotting time (TCT), soluble fibrin monomer (SFM) and fibrin-fibrinogen degradation products (FDP). Retrospective determination of the cause of the colic and outcome (survival vs non-survival) was carried out. All patients examined had at least one abnormal parameter with the frequency being: Increased SFM 67 per cent; prolonged PTT 63 per cent; prolonged TCT 50 per cent; elevated plasma fibrinogen 46 per cent; reduced platelet count 29 per cent; reduced plasma AT 29 per cent; prolonged PT 25 per cent; and elevated serum FDP 21 per cent. When survivor and non-survivor groups were compared there was little difference in the frequency of abnormalities such as elevated SFM, elevated fibrinogen and prolonged PTT. The abnormalities which had the greatest frequency difference between non-survivors and survivors, and therefore the greatest prognostic value, were decreased AT greater than prolonged TCT = prolonged PT greater than elevated FDP greater than reduced platelet count. The frequency of these abnormalities in non-survivors compared to survivors was 8.6:1, 7.1:1, 5.7:1 and 3.6:1, respectively. The average number of abnormal parameters in non-survivors (five) was significantly greater than in survivors (two).

Bleeding in cirrhotic patients: a precipitating factor due to intravascular coagulation or to hepatic failure?

In 24 cirrhotic patients at different stages of hepatic failure, factor VIII:C (F VIII:C), factor VIIIR:AG (F VIIIR:AG), factor VIII AG/C ratio (F VIII AG/C), and serum fibrin-fibrinogen degradation products (FDP) were investigated. In 11 of the 24 patients, several instances of gastrointestinal bleeding due to esophageal varices rupture were documented and 5 patients died of unarrestable bleeding. In our study, we evaluated whether the cause of bleeding was the development of intravascular coagulation or the severity of hepatic failure. A statistically significant difference between F VIII:C, F VIIIR:AG/C ratio, and serum FDP was found in bleeding in comparison with non-bleeding patients. An inverse correlation between the F VIII:C plasma level and serum FDP as well as a direct correlation between F VIII AG/C ratio and serum FDP in the group of bleeding patients were also found. These data seem to suggest a hypercoagulable state which was more significant in the 5 patients who died owing to bleeding. Furthermore, only 1 of these patients had severe hepatic failure. From this study it appears that, in cirrhotic patients, bleeding is related more to the appearance of disseminated intravascular coagulation, as a consequence of both hemodynamic and endothelial changes, than to the degree of hepatic failure itself.

Evaluation of New Latex FDP Assay

The Dade latex FDP (fibrin/fibrinogen degradation products) reagents, recently introduced to the market, were evaluated against the Thrombowellco latex FDP reagents and the tanned red cell hemagglutination inhibition immunoassay (TRCHII). The Dade reagents gave positive results in the 10-40 µg/mL range in four of 20 normal sera; none of these samples was positive (ie,⩾10 µg/mL) with Thrombowellco or TRCHII reagents.With 54 patient samples, almost 60% showed FDP titers in the range of 20-80 µg/mL with the Dade assay; only about 30% of the same samples were shown to be in that range with the other two methods. In separate experiments,the agitation time was prolonged from two to 2.5 minutes. Five of eight normal sera turned positive with the Dade method, while none did so with the other two methods. The results indicate an unusual sensitivity of the Dade product toward serum FDP.

Distinction between fibrinogen and fibrin degradation products produced during disseminated intravascular coagulation in childhood.

Fibrin-fibrinogen degradation products in serum from five children with disseminated intravascular coagulation (DIC) were characterized using a method of immunoabsorption followed by SDS-polyacrylamide gel electrophoresis. All of the samples contained not only fragment D-dimer which was produced on plasmin lysis of cross-linked fibrin, but also fibrinogen degradation products (fragments X, Y and D). These results suggest that both fibrinogenolysis and fibrinolysis take place simultaneously in DIC.

Urinary fibrin-fibrinogen degradation products and intraglomerular fibrin-fibrinogen deposition in various renal diseases

The typing of the urinary fibrin-fibrinogen degradation products (FDP) and the deposition of fibrin-fibrinogen, factor XIII-subunit A (XIII-A) and factor XIII-subunit S (XIII-S) in the glomeruli were investigated in the children with several kinds of renal diseases. In acute glomerulonephritis with diffuse proliferative lesion, the urinary FDP were composed of fragments X,Y,D and E. There was no D-dimer fragment detected in the urine, although, mild deposition of fibrin-fibrinogen, XIII-A and XIII-S in the glomeruli was observed. The urinary FDP may be derived from plasma fibrinogen or serum FDP. In nephrotic syndrome with diffuse proliferative or focal global sclerosing lesion and in purpura nephritis with mesangial proliferation with crescents, the urinary FDP consisted of fragments X and Y, and lacked in D-dimer. In these cases, the major part of fibrin-fibrinogen in the glomeruli might be fibrinogen or non-cross-linked fibrin, and FDP excretion might arise from glomerular permeability or from lysis of fibrinogen or non-cross-linked fibrin. In one patient with hemolytic uremic syndrome and in another patient with systemic lupus erythematodes nephropathy, intense deposition of fibrin-fibrinogen, XIII-A and XIII-S within the glomerular capillaries or mesangial area were observed. In the urine of those cases, D-dimer was detected, which seems to reflect the lysis of cross-linked fibrin in the glomeruli.

Plasma antithrombin III level in patients with renal diseases

The authors have reported the abnormalities of the blood coagulation and fibrinolysis in patients with renal diseases. Recently, antithrombin III (AT III) is emphasized as the most important of all the clot inhibitory factors.The purpose of this study is to evaluate the significance of plasma AT III in patients with renal diseases.Plasma AT III level, soluble fibrin monomer complex (SFMC) level and other factors relating to the blood coagulation and fibrinolysis were estimated in 31 patients with renal diseases and 14 normal control subjects. The patients consisted of 17 cases with nephrotic syndrome (9 in acute stage, 8 in latent stage), 4 with chronic glomerulonephritis and 10 with chronic renal failure. Plasma AT III was measured by single radial immunodiffusion method, and SFMC by Lipinski's method.The mean levels of plasma AT III (mg/dl) and SFMC (O. D.) were 27.9mg/dl and 0.79 O. D. in controls, 17.6mg/dl and 0.39 O. D. in acute stage, 30.3mg/dl and 0.93 O. D. in latent stage, 30.0mg/dl and 0.80 O. D. in chronic glomerulonephritis, 24.3mg/dl and 1.19 O. D. in chronic renal failure.Plasma AT III levels were lower in the acute stage of nephrotic syndrome and in chronic renal failure than those in controls. SFMC levels were higher in the acute stage of nephrotic syndrome and in chronic renal failure than those in controls. Though no correlation was found between plasma AT III and SFMC or plasma AT III and fibrinogen in controls, a negative correlation existed between plasma AT III and SFMC (r=-0.61, p<0.01) or plasma AT III and fibrinogen (r=-0.49, p<0.01) in renal diseases.No correlation was found between plasma AT III and serum FDP (fibrin/fibrinogen degradation products) in renal diseases. However, plasma AT III levels were significantly lower in patients with abnormally high serum FDP level (≥8μg/ml) than those in patients with normal serum FDP (<8μg/ml) (p<0.01). In renal diseases no correlation was found between plasma AT III and the activity or the antigenicity of factor XIII.Low plasma AT III with high SFMC has been often reported in the disseminated intravascular coagulation, which is apt to arise in renal diseases. And the author's results concerning coagulation and fibrinolysis can be regarded as pathophysiological features of the disseminated intravascular coagulation phenomenon in renal diseases.

Effects of Splenectomy on Blood Coagulation and Fibrinolysis in Patients with Liver Cirrhosis: Possible Role of the Spleen in Haemostasis.

Blood coagulation and fibrinolysis before and after splenectomy was studied in 74 cases of liver cirrhosis. A hypocoagulable state was found before splenectomy, but the platelet count, and the levels of fibrinogen, plasminogen, ±2-macroglobulin and antithrombin III increased significantly after splenectomy (p < 0.05 to p < 0.001). A marked improvement was observed on the values of r (reaction time), k (clot formation time) and ma (maximal amplitude) of thrombelastograms (p < 0.05 to p < 0.001). The prothrombin time was reduced after the surgery, but not significantly (0.05 < p < 0.1). The levels of arantitrypsin remained almost unchanged, while serum fibrinogen-fibrin degradation products (FDP) showed a slight decrease postoperatively.The immunohistologic study of the spleen excised from 7 cases with liver cirrhosis, with the use of the direct immunofluorescence technique, demonstrated the deposits of fibrin in the splenic cords in all cases. It was not recognized in the spleens of 4 cases without cirrhosis used as the control.A further study of the spleen weight and plasma fibrinogen level showed that a significant inverse correlation exists between these two parameters (p < 0.01).These findings suggest that localized intravascular coagulation (LIC) occurs in the enlarged spleen associated with liver cirrhosis.

Coagulation Factors in Renal Adenocarcinoma

Coagulation factors, including plasma fibrinogen, serum fibrinogen-fibrin degradation products, platelet counts and prothrombin times, were studied in patients with renal adenocarcinoma. Plasma fibrinogen levels were elevated and correlated with tumor stage, disease activity and therapy. Fibrinogen-fibrin degradation product levels also were elevated, although such elevations did not correlate with other parameters. Platelet counts and prothrombin times were normal. Fibrinogen may be a valuable marker of disease activity in patients with renal carcinoma. In addition, since significant intratumoral fibrin deposits have been demonstrated anticoagulants or fibrinolytic agents may enhance cytotoxic therapy and should be considered in adjunctive chemotherapeutic protocols.

Experimental study of the effect of β-adrenergic blockade on fibrinogen synthesis

Hyperfibrinogenemia has been found in the cases with cancer, inflammatory disease and several types of injuries. In previous observations, the hyperfibrinogenemia associated with cancer was striking in view of the rapid turnover rate of 131I-labeled fibrinogen. It seems of interest to study the regulation of fibrinogen production in hyperfibrinogenemia.Recently, Pickart et al. reported that fibrin-fibrinogen degradation products (FDP) which potentiated epinephrine effect on beta-adrenergic receptors in fat cells, would enhance the mobilization of free fatty acids (FFA) from depot fat and saturated FFA stimmulated the production of fibrinogen in the liver.We studied the effect of beta-adrenergic blockade on fibrinogen synthesis in rats with tumor, inflammation and intraperitoneal injection of toxohormone. The serum FDP level and the FFA/Albumin ratio were rised as much as the plasma fibrinogen level in rats following subcutaneous injection of turpentine oil and intraperitoneal injection of toxohormone.The enhanced fibrinogen synthesis was suppressed significantly in the rats treated with the beta-blocker every 4 hours as measured by incorporation of 14C-L-leucine at 12 hours after recieving of turpentine or toxohormone. However, the beta-blockade did not alter the incorporation of labeled amino acid into the serum albumin in these experiments.The effects of beta-blocker on the concentration of plasma fibrinogen in tumor bearining rats were examined. The rats were given the beta-blocker every 6 hours by stomach sonde between 5th and 8th day after the subcutaneous inoculation of Yoshida sarcoma cells. On 8th day, fibrinogen, albumin and FFA in the blood were assayed. The plasma fibrinogen level and the FFA/Albumin ratio in tumor bearing rats were reduced by the administration of beta-blocker.On the other hand, the beta-blockade did not interrupt the activation of fibrinolysis in rats with inflammation induced by turpentine oil but enhanced the phagocytic activity of reticulo-endotherial system when measured by carbon clearance in normal animals.In this study, it was postulated that beta-adrenergic receptor might relate to enhancement of fibrinogen synthesis in hyperfibrinogenemia associated with inflammation, tumor and injection of toxohormone.Furthermore FDP and FFA might involve in the regulating factors of fibrinogen synthesis.

The bood coagulation and fibrinolytic study in obstructive jaundice

In order to know the causative factors of abnormal bleeding tendency following surgery on the patients with obstructive jaundice, fibrin/fibrinogen degradation products (FDP) including fibriolytic activity, platelet counts, platelet retention and aggregation, and the blood coagulation systems were investigated.Total 20 patients with obstructive jaundice were studied. 16 of them had malignant tumor and the rest four had choledocholithiasis.The serum FDP level was elevated significantly in most of these patients and showed a some correlationship with the increase of the serum total bilirubin and alkalinephosphatase values. However, the elevation of FDP could not be explained only by the degree of obstructive jaundice.The serum FDP level did not show any intimate correlation with the serum γ-globulin and BUN values. This might suggest that the serum FDP level is under the influence of some other agents rather than the liver or kidney disfunction.The serum FDP elevation is often appreciated as one of the reliable diagnostic indicator for the syndrome of DIC. In general, the syndrome of DIC usually accompanies abnormal decrease of plasma fibrinogen level, platelet counts and prolongation of the prothrombin time. On the contrary, in these 20 cases these lab. results were within normal limits.In studying the relationship between the elevation of serum FDP or serum bilirubin and platelet retention or platelet aggregation, platelet aggregation was suppressed in these patients with either the marked increase of FDP level or the elevation of serum total bilirubin value.But or on the other hand, fibrinolytic activity, which was measured by the fibrin plate method and euglobulin clot lysis time was found not to be increased.In spite of the presence of high serum FDP, the syndrome of DIC was not apparent. It is not clear that the elevation of serum FDP was due to malignant tumor, chronic DIC or obstructive jaundice. However, these data suggest that the elevation of serum FDP have some influence on the postoperative bleeding tendency in the patients with obstrutive jaundice.

Fibrin/fibrinogen degradation products (FDP) in urine and serum after prolonged heavy exercise.

The presence of FDP in the urine, known to be a sensitive indicator of various kidney disorders, was studied in 14 well-trained men participating in a 70-km cross-country ski race. None of the urine samples contained FDP on the day before the race. Immediately after the race, 4 samples contained FDP. High molecular weight FDP were found in 2 of them, whereas 2 others contained low molecular weight products only. 2 days after the race, 1 of these subjects still had FDP in the urine. In addition, 2 newly FDP positives were observed. Serum FDP were slightly elevated in 2 subjects before the race, and in another subject immediately after the race. The presence of urinary FDP did not correlate either with urinary albumin or uromucoid, or with serum FDP. A drop in plasma fibrinogen immediately after the race was noted in all subjects. It is suggested that the present observations may reflect a transient hyperproteolysis (coagulation and fibrinolysis) in the glomerular circulation, including fibrin formation and dissolution, associated with a transient damage of glomerular capillaries.