Antibodies to Endothelial Cells in Patients with Behçet's Disease

Autoantibodies that bind to endothelial cells have been identified in patients with several forms of vasculitis. Behçet's disease—a multisystem inflammatory disorder of unknown etiology—is associated with thrombosis in addition to systemic manifestations resulting from small and large vessel vasculitis. We studied 72 Turkish patients (33 female, 39 male) with Behçet's disease in order to investigate the prevalence of antiendothelial cell antibodies (AECA) and to examine their possible relationship with clinical and laboratory features of the illness. Sera from 30 healthy Turkish people were used as controls. Human umbilical vein endothelial cells were cultured and used unfixed in a cellular ELISA to detect AECA. IgG and/or IgM AECA were found in 13 (18.1%) patients but not in healthy controls. Antiendothelial cell antibodies did not induce complement-mediated cytotoxicity as assessed by 51Cr release assay and the binding was not due to immune complexes. The prevalences of acute thrombotic events and retinal vasculitis at the time of the AECA assay among patients with AECA were significantly higher than those in patients without AECA. Laboratory parameters of active disease were higher in patients with AECA. There was no correlation between other clinical and laboratory features of Behçet's disease and AECA. Anticardiolipin and antineutrophil cytoplasmic antibodies were negative in our series, excluding a possibility of crossreaction with AECA. Our results suggest a possible role of AECA in association with thrombosis and vasculitis in patients with Behçet's disease.