INCIDENCE OF DEFECTIVE T-PA RELEASE IN 158 UNRELATED YOUNG PATIENTS WITH VENOUS THROMBOSIS IN COMPARISON TO PC-, PS-, AT III-, FIBRINOGEN- AND PLASMINOGENDEFICIENCY

The incidence of defective T-PA release in 158 young unrelated patients (<45 years old) with deep vein thrombosis was studied and compared to that of PC-, PS-, AT III-, fibrinogen- and plasminogen deficiency. Thrombotic episodes were documented using venography with contrast medium. Venous occlusion test (VO) over 20 min. was performed in all patients, 8-12 weeks after thrombosis. T-PA antigen (Biopool kit) , T-PA activity (on fibimplates) and PAI (T-PA-inhibitor, Biopool kit) were measured before and after VO in the fasting morning samples. Furthermore we investigated the functional and immunologic levels of PC,PS,AT III, fibrinogen and plasminogen. We detected 28 patients (15 females, 13 males)= 17.7% with abnormal T-PA release. In these patients the VO test was repeated three times in an interval of 6-8 weeks. Release of T-PA activity and T-PA-Ag was diminished in all these patients. PAI levels were enhanced in 12 of these 28 patients. The rate of recurrency of thrombosis was 52%. A family history of thrombosis was reported only in 20%

The incidence of PC def. was 9.4%, of PS def. 6.3%, of AT III def 5%, of dysfibrinogenemia 0.6% and of plasminogen def. 1.2%. No combined defect of abnormal T-PA release with other known hereditary coagulation or fibrinolysis disorders could be detected.In 11 healthy volunteers we investigated 4 different time periods of VO, 5, 10, 15 and 20 min. in an interval of 10 days in order to find the suitable time for VO. It was striking that T-PA activity (on fibrin plates) did not decrease to the same extent as T-PA-Ag. The different behaviour is demonstrated on table 1. Decrease in % is compared to the values of 20 min. VO.