The association between natural inhibitors of coagulation and thrombophilia was investigated in 35 patients with Behçet's disease. Antithrombin III and protein C levels were measured using synthetic chromogenic substrate methods, and protein S levels by quantitative enzyme-linked immunosorbent assay. There were no significant differences between patients and controls in plasma antithrombin III, protein C and free protein S concentrations. We conclude that there was no evidence of a primary coagulation inhibitor abnormality in patients with Behçet's disease.
