EFFECTS OF LEUKOCYTES, PLASMIN AND THROMBIN ON CLOTTING FACTORS - COMPARATIVE INVITRO STUDY

In an in vitro investigation the influence of leukocyte extract, plasmin and thrombin on various clotting factors was compared. The clotting factor preparations used as substrates were fraction I-0 (fibrinogen, factor VIII and factor XIII) and Preconativ (factors II, VII, IX and X) (Kabi, Sweden). The various factor VIII activities (VIII:C, VIIIR:Ag - electroimmuno assay, VIIIR:Ag -immunoradiometric assay and VIIIR:RCF) and factor XIII subunit a showed a degradation by leukocyte extract resembling that of plasmin. During incubation thrombin first activated and then destroyed VIII:C. The prothrombin complex (factors II, VII and X) and the separate activities of factor VII and factor IX were degraded by the leukocyte extract as well as by plasmin. A fibrin/ fibrinogenolytic activity by the leukocyte extract was demonstrated. Multiple defects in the coagulation and fibrinolytic systems complicating many disorders might well be produced by proteases from leukocytes and injured tissue cells. © 1979.