Factual or artificial inhibition of fibrinolysis and the occurrence of venous thrombosis in 3 cases of Behçet's disease.

3 patients with Behçet's disease were studied for their fibrinolytic status during exacerbation of the disease accompanied with thrombotic complications. All 3 patients exhibited low euglobulin fibrinolytic activity. This, however, could be attributed to an artificially increased coprecipitation of inhibitors, i.e., C1-inactivator in the euglobulin fractions. This phenomenon correlated with and was possibly related to inflammatory reactions in the patients. The most severely diseased patient only showed an increased plasmin inhibition in the plasma and a decreased response to venous occlusion. The increased plasmin inhibition was due to a slow type of inhibition, which could not be attributed to known protease inhibitors in blood. Its physiological relevance to fibrinolysis is questionable. There was no evidence for relevant general deviations in the fibrinolytic system in Behçet's disease; only for the severe case may the decreased fibrinolytic potency revealed by venous occlusion have contributed to the extent of the thrombotic manifestations.