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During postoperative prophylaxis of thrombosis using subcutaneous low-dose heparin thrombocytopenia and consumption coagulopathy without manifest haemorrhage were observed in a female patient with gynaecologic problems on the tenth postoperative day. Using gel-electrophoresis, demonstration of cross-linked fibrin derivatives, which occur only after contact with thrombin, was proof that disseminated intravascular coagulation must have been present. Cancellation of heparin prophylaxis was sufficient for regression of the haemostatic disorder. Platelet function tests performed two months later showed as the only reproducible abnormality that the patient's plasma caused inhibition of desaggregation of normal platelets only when heparin was present. The remarkably close chronologic connection of heparin prophylaxis with thrombocytopenia and consumption coagulopathy suggests a possible causal connection. However, at present the possibly heterogeneous aetiology cannot be explained satisfactorily.

Plasma from a patient with a sever “Dead Fetus Syndrome”, who was treated with Reptilase, contained high molecular weight derivatives of fibrinogen in an amount of one fourth of the total fibrinogen content. The bulk of the derivatives did not dissociate in the presence of SDS and urea. Chain analysis revealed the presence of γ-γ dimers and a decrease of single α- and γ- chains. It might be assumed that the presence of covalently linked defect oligomers of fibrin in plasma indicated intravascular coagulation which probably had been aggravated by the application of Reptilase.

Sepsis of the newborn induced by gram negative bacteria, especially E. coli is often accompanied by a severe coagulation disorder. It can be treated by blood exchange transfusion (ET) with heparinized blood. In this study the hematological effect obtained by the exchange transfusion was investigated in rabbits after induction of a generalized Shwartzman reaction by two spaced injections of endotoxin (75 microgram/kg) 24 hrs. apart. Three groups of 6 animals each were investigated: group I: without endotoxin but with ET (controls); group II: endotoxin without ET; group III: endotoxin with ET. Fibrinogen, soluble fibrin monomer complexes (SFMC), fibrin(ogen) degradation products (FDP), platelet- and leukocyte counts and urine volume (ml/hr) were estimated. In group II a decline in the fibrinogen level, and in platelet and leukocyte count, as well as an increase in SFMC and FDP could be observed from 6 hrs. on after the second endotoxin injection. In group III 6 hrs. after the second endotoxin injection, exchange transfusion with heparinized blood was performed. Variance analysis showed significant differences in all parameters, except in the urine volumes after exchange transfusion between group III and group II. By exchange transfusion an approach of the values towards the values of the controls could be recognized. The findings indicate, that by blood exchange transfusion the hematological consequences of the endotoxin induced DIC can be corrected, while the dysfunction of the kidneys can be improved only slightly.

In 20 patients with acute leukemia the thrombin-mediated fibrin monomer complexes (SFMC) were determined before and after remission induction chemotherapy for several weeks to assess the extent of hypercoagulability. Increased levels of SFMC were observed in patients with high leukocyte cell counts after induction chemotherapy which may reflect the release of thromboplastic material from destructed leukemic cells. Patients with low leukocyte counts showed only a moderate increase in SFMC. A low concentration of antithrombin III (

Following a single endotoxin injection circulating soluble fibrin monomer complexes (SFMC) were demonstrated in rabbits. The application of 125 I-fibrinogen after anticoagulation of the animals resulted in the incorporation of labelled fibrinogen in circulating SFMC. 125 I-fibrinogen dissociated from SFMC during affinity chromatography on agarose coupled fibrinogen (Fg-ag). The study is in agreement with the assumption of an association dissociation equilibrium between fibrinogen and fibrinmonomers in circulating SFMC.

A radioimmunoassay has been established to determine the reactive antigen related to human fibrinogen CNBr peptide F-CB3 in human serum. The amount of antigen found in healthy subjects was in the range of 1 to 10 pmoles per milliliter. A 10 to 30 fold increase in antigen level could be demonstrated in a group of patients with various haemorrhagic disorders and in patients having undergone cesarean section. Plasma levels of fibrinogen and of soluble fibrin monomer complexes were also increased in these patients.

Circulating crosslinked fibrin was observed in 19 patients with coagulation disorders in obstetrics (amniotic fluid embolism, abruptio placentae, endotoxin shock following septic abortion etc.). Gel filtration of B-Alaprecipitated plasma samples and chain characterization of isolated fibrin derivatives by SDS-PAA gel electrophoresis after reduction with mercaptoethanol were performed. Fibrin was observed in amounts up to 30 mg/100 ml plasma. Subunit structure analysis revealed that circulating fibrin is composed of γ-γ-γ-γ′ (85 000 molecular weight), β, (β′) (52 000 mol. wt.), γ, β″ (44 500 mol. wt.), α (25 000 mol. wt.) and α ″ (15 000 mol. wt.) chains. This composition reflects the action of thrombin, factor XIII and plasmin and agrees with the assumption of γ chain crosslinked late-X oligomers (intermediate polymers). Their mean molecular weight is 1–2 million daltons. Electron microscopy of fibrin following freeze etching technique shows that di-, tri- and higher-ordered oligomers are arranged in an end-to-end association. In vitro produced partially crosslinked oligomers of late-X fragments exhibited a very similar subunit and macromolecular structure.

In patients with DIC crosslinked high molecular fibrin derivatives (CL-HMD)are observed, which are eluted by gel filtration in the exclusion volume (MW>106 ). Characterization by PAGE revealed that their subunits are similar to crosslinked fdp X. To evaluate their origin, in vitro studies were performed on fibrinolysis products obtained in three ways; (1) by SK-induced fibrinolysis of crosslinked fibrin, (2) by simultaneous action of thrombin and plasmin on Fg in presence of F XIII and Ca++, and (3) by limited fibrinogenolysis and subsequent action of thrombin and F XIII upon the resultant early FDP. Reaction (1) resulted in low mol derivatives (LMD) only (D-D, E ), which do not complex with Fg. In contrast, reaction (2) and (3) resulted in HMD and LMD. The former are composed of Cl-‘X’ and complexes of mainly ‘X’ and ‘Y’. In reaction (3) early X precipitates when it is transformed to ‘X’ and to CL-’X’. Late X remains soluble after transition to ‘X’ and CL-’X’. The results suggest, that CL-HMD observed in patients with DIC are not derived from fibrin clots but formed from Fg under combined action of plasmin and thrombin

D dimer and related crosslinked fibrin derivatives were measured in plasma of normal subjects and in patients with various disorders. In 23 healthy, young females low plasma levels were found (mean 47 ng/ml). In 12 patients with deep vein thrombosis, moderately elevated levels (mean 593 ng/ml) were seen. Higher levels were found in 6 patients with pulmonary embolism (mean 3,337 ng/ml). The highest values occurred in 4 patients with severe intravascular coagulation (31,000 to 390,000 ng/ml). In 22 patients with ovarian cancer and in 21 patients with other gynecologic carcinoma, normal to highly elevated levels of D dimer like material were found. These values corresponded well to concentrations of tumor marker CA 125, measured in the same samples, and to tumor activities staged in these patients based on clinical examinations. Very high values of crosslinked fibrin derivatives (75,000-525,000 ng/ml) were determined in ascitic fluid of patients with ovarian cancer.

Covalently linked heterogeneous fibrin-fibronectin compounds were detected in ascitic fluid of 31 patients with advanced ovarian cystadenocarcinoma by means of enzyme-linked immunosorbent assay techniques, immunoaffinity chromatography, and Western blot analysis. Deposition of fibrin and fibronectin could also be demonstrated immunohistochemically in Carnoy-fixed tissue sections. Fibrin and fibronectin were found in the tumor stroma within tumor nests and more prominently in stroma surrounding the tumor nests. The association of fibrin and fibronectin was especially pronounced in the stroma surrounding the tumor islands. Fibronectin was also found to be associated with stroma cells. Areas within the tumor stroma showed superimposed staining for both fibrin and fibronectin supporting the assumption that the covalently linked fibrin-fibronectin conjugates found in ascitic fluid may stem from the provisional tumor stroma by proteolytic release.

The article reports on measurements of D dimer, a terminal plasmic lysis product of crosslinked fibrin, with an enzyme immunoassay (ELISA) employing recently developed specific monoclonal antibodies. Due to its sensitivity the test can be used on plasma samples. The D dimer concentrations in patients with deep vein thrombosis diagnosed by laboratory apparatus were significantly increased compared to a control group; in one patient with additional pulmonary embolism, the level was even higher. Moderately elevated concentrations of D dimer were observed in the hypercoagulable state of pregnancy, puerperium and during the postoperative course. This reduces the specificity of the test with regard to the recognition of thromboembolic episodes under these conditions. Obstetric patients with disseminated intravascular coagulation (DIC) showed excessively increased levels of D dimer. Hence, a marker function with regard to the recognition of thromboembolic disease can be attributed to the D dimer; the diagnosis of DIC can be confirmed if very high concentrations are detected.

Incubation of fibrinogen with small amounts of thrombin resulted in the occurrence of soluble fibrin monomer complexes. These complexes consisted predominantly of a derivative with a higher molecular weight than that of fibrinogen. It was characterized by its relative electrophoretic mobility in 5% PAA gel (0.28 X 10(-5) cm2/V X sec) and its elution position prior to the fibrinogen peak following gel filtration. Using adsorption chromatography on insolubilized fibrinogen the derivative dissociated at a ratio of almost 1 : 1 into one part which was adsorbed and into fibrinogen which was not adsorbed. The part which was adsorbed seemed to be the thrombin mediated fibrin monomer. This study confirms the concept that dissociable dimeric fibrinogen-fibrin monomer complexes occur after limited action of thrombin on fibrinogen.

The quantitative estimation of soluble fibrin monomer complexes (SFMC) was applied to evaluate the state of hypercoagulability during pregnancy and delivery. Blood samples from 67 healthy primi and multiparae, 6 to 40 weeks pregnant, and from a group of 8 women in labour and after delivery of the placenta were examined. Fibrinogen and SFMC were precipitated from plasma by precipitation with beta-alanine. Gel filtration (4% agarose) of the redissolved precipitate resulted in a separation of SFMC and fibrinogen. This enabled a quantitative estimation of the SFMC concentration (with-in assay precision: coefficient of variation=8%). The % amount SFMC of the total fibrinogen content increased from 2.6 +/- 0.4 to 4.9 +/- 1.3% (mean and standard deviation) to week 40 of pregnancy. During delivery an additional statistically significant increase occurred. Chain analysis of SFMC showed a decreased amount of alpha-chain indicating plasmin activity. gamma-gamma-dimers as residuals of intermolecular covalent bonding were not observed. The quantitative estimation of SFMC during pregnancy and delivery demonstrates that a state of hypercoagulability during gestation can be evaluated by measuring the catabolic products of fibrinogen. This may lead to a differentiation from severe intravascular coagulation and to an early diagnosis of thromboembolic disease or consumption coagulopathy.

Fibrinogen and plasma were treated with thrombin or 17 α-ethinyl estradiol and studied by gel and affinity chromatography. Fibrin monomer complexes could only be demonstrated in thrombin incubated samples. 17 α-ethinyl estradiol did not alter the fibrinogen molecule. The fact that this is in contrast to a recent report is discussed.

Various biochemical processes in hematoma fluid arising from chronic subdural bleeding have not yet been clearly explained. We examined the question whether formation of hematoma fluid after onset of bleeding is preceded by complete clotting with fibrin formation and subsequent lysis of the clot. 22 samples of hematoma fluid taken during operation were used. The protein content was 5.7 +/- 9.8 g/l (mean +/- SD), and coagulable fibrinogen could not be demonstrated whereas 0.99 +/- 0.45 mg/ml fibrin(ogen) break-down products were found immunologically. The high levels of crosslinked D-D fibrin derivatives (0.32 +/- 0.26 mg/ml) were conspicuous: there was a correspondingly high degree of crosslinking (86.2% x/- 12.2%) of the fibrin(ogen) break-down products (calculated from the proportion of dimeric to monomeric gamma-chains). Monoclonal antibodies specific for D-D were employed for the first time to answer the question. The characterization of the crosslinked fibrin derivatives together with their submolecular sub-units and the quantification of the D-D content serve to prove that fibrin is both formed and broken down in chronic subdural hematomas.