Effect of elastase on the fibrinolytic activity in patients with thrombotic disorders.

The response of coagulation and fibrinolysis to venous occlusion test (VOT) was studied in 23 patients with thrombotic disorders before and after 4.7 (3-9) months' administration of elastase (1800 EL. U./day).The patients were classified into “normal” and “low” responders according to the grade of response to VOT before treatment. After administration of elastase, four of 8 low responders showed improved response, whereas 2 of 15 normal responders changed into low responders. Although plasminogen activator activity before and after VOT did not change after the administration, plasminogen activator inhibitor (PAI) activity at rest decreased after the administration. Tissue plasminogen activator and PAI-1 antigen, crosslinked fibrin derivatives, von Willebrand factor antigen and antithrombin III did not change after the administration.These results suggest that elastase may improve the reduced fibrinolysis in case of thrombotic disorders due to high PAI activity. Further analysis would be necessory to clarify the mechanisms of the effect of elastase on fibrinolytic system in larger series.