Fibrinolytic Activity and Haemagglutination Inhibition Immunoassays

Concentrations of fibrinogen-fibrin break-down products (b.d.p.), above 10 ug/ml of serum (+EACA), estimated by haemagglutination inhibition immuno assays, were seldom found in healthy people. In 51 patients with coronary sclerosis and in 31 with other atherosclerotic diseases the amounts were in the lower part of normal range. The mean concentration in 16 patients with metastatic carcinoma was 86.7 and in 16 with hepatic cirrhosis 21.1 ug/ml. 93 patients with other diseases were examined. Huge amounts might be found even when fibrinolytic activity in the blood was very low. Several experiments indicate that b.d.p. also are formed extravascularly and presumably also by other proteases than plasmin. Short-term stimulation of fibrinolytic activity with nicotinic acid (41 patients), venous stasis (35 pts.) and physical exertion (21 pts.), and long-term stimulation with male hormones (5 pts.), metformin (4 pts.), clofibrate (3 pts.), tolazamid (4 pts.) and ethyloestranol + diguanides (11 pts.) was not followed by in vivo increase in b.d.p.