Protein S deficiency and antibodies to protein S in patients with Behcet's disease

Thrombosis occurs in 20 to 30 % of patients with Behcet's disease (BD). Most of the reported hemostatic abnormalities are related to the inflammatory syndrom. We have assessed the activity of antithrombin III, protein C and protein S (PS), in 30 patients with ED and in 30 healthy controls Thrombosis antecedents were found in 16 patients. Antithrombin III and protein C were within the normal range, however free PS and PSactivity were significantly decreased in patients as compared to control group.PS deficiency detected in eight patients, was associated to thrombosis in 6 of them. No correlation was found between free PS/total PS ratio and C4bBP levels. Antibodies to PS were screened by ELISA and were present in 6 patients,associated to PS deficiency in 4, and to thrombosis antecedents in 5 cases..PS deficiency was transient in two patients, associated to a persistant antiPS in one of them.These findings suggest that auto-immune acquired PS deficiency may be involved in the pathogenesis of thrombotic events in ED. (C) 1997 Elsevier Science Ltd.