Fibrinolytic response to venous occlusion for 10 and 20 minutes in healthy subjects and in patients with deep vein thrombosis.
Tissue plasminogen activator (t-PA) activity, t-PA antigen (t-PA:Ag) and t-PA inhibitor activity (PAI) were measured at rest and during venous occlusion (VO) for 10 and 20 min in 21 healthy subjects and 80 patients with venous thromboembolic disease. The expected t-PA release was seen in the controls. However, the release was found to be nonlinear and 63% of the t-PA:Ag was released during the last 10 min of VO. Defective release of t-PA:Ag and/or t-PA activity was found in 25 patients (31%). Three subgroups could be identified: 10 patients (13%) with low t-PA:Ag release (PRI), 6 patients (8%) with a high basal level of PAI (PR II) and 9 patients (11%) who had only low t-PA activity after VO. Using VO for 10 min only, 60%, 83% and 44% of the patients in PR I, PR II and PR III, respectively, were recognized. Using VO for 20 min only, the figures were 80%, 83% and 89%, respectively. The use of t-PA values corrected for the haemoconcentration during VO influenced the patients' classification as poor responders to only a minor degree. It is concluded that in screening for hypofibrinolysis VO is needed for at least 20 min, but that the sensitivity of the test increased by using VO for both 10 and 20 min.
Petäjä
J
J
Finnish Red Cross Blood Transfusion Service, Helsinki.
D000328:Adult; D000941:Antigens / Q000097:blood; D003250:Constriction; D005260:Female; D005342:Fibrinolysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015849:Plasminogen Inactivators / Q000097:blood; D013924:Thrombophlebitis / Q000097:blood*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000097:blood / Q000276:immunology; D014680:Veins
D000941:Antigens; D015849:Plasminogen Inactivators; D010959:Tissue Plasminogen Activator