Vascular involvement in Behcet's disease:: Relation with thrombophilic factors, coagulation activation, and thrombomodulin

PURPOSE: Thrombosis, usually venous, occurs in 10% to 25% of patients with Behcet's disease, but its pathogenesis is poorly understood. We evaluated parameters of hemostasis and their relation with thrombosis in a series of patients with Behcet's disease. SUBJECTS AND METHODS: We studied 38 patients with Behcet's disease (13 with venous thrombosis), 38 patients with venous thrombosis without thrombophilia, and 100 control subjects. Levels or presence of protein C, protein S, antithrombin, methylenetetrahydrofolate reductase C677T, factor V Leiden, prothrombin gene G20210A, antiphospholipid antibodies, plasminogen, tissue-type plasminogen activator (tPA), type-1 tPA inhibitor (PAI-1), PAI-1 4G/5G polymorphism, prothrombin fragment 1+2, plasmin/alpha(2)-antiplasmin complexes, thrombomodulin, and activated factors VII and XII were determined. RESULTS: There were no deficiencies in protein C, protein S, antithrombin, or factor V Leiden in the patients with Behcet's disease, nor was there evidence of most other thrombotic abnormalities. Compared with control subjects, however, the Behcet's disease group had elevated mean (+/-SD) levels of prothrombin fragment 1+2 (2091 +/- 1323 pmol/L vs. 804 +/- 398 pmol/L, P<0.001), plasmin/alpha(2)-antiplasmin complexes (410 220 mug/L vs. 214 +/- 92 mug/L, P<0.001), and thrombomodulin (37 +/- 24 ng/mL vs. 27 +/- 10 ng/mL, P<0.001). These levels did not differ between patients with or without thrombosis. CONCLUSION: Thrombophilic factors do not seem to explain most thromboses in Behcet's disease. There is increased thrombin generation, fibrinolysis, and thrombomodulin in Behcet's disease, but these abnormalities are not related to thrombosis. (C) 2002 by Excerpta Medica, Inc.