Anti-endothelial cell antibodies in patients with sarcoidosis

Anti-endothelial cell antibodies (AECA) are circulating antibodies that bind to endothelial antigens and induce endothelial cell damage. These antibodies have been detected in patients with collagen vascular disease and systemic vasculitis. Sarcoidosis is a multiple granulomatous disorder of unknown etiology, and its clinical presentation, organ involvement, and prognosis are highly diverse. In this study, we aimed to investigate the expression of AECA in patients with sarcoidosis. We also examined whether these antibodies could serve as a marker for the activity, severity, and prognosis of sarcoidosis.

Forty sarcoidosis patients, whose diagnosis was established by clinicoradiologic findings and histologic confirmation of noncaseating epithelioid cell granulomas, were studied. Serum and BAL samples were examined for AECA by cellular enzyme-linked immunosorbent assay (ELISA) using human umbilical vein endothelial cells. The findings were expressed in terms of an ELISA ratio (ER). Fifty-seven subjects without any clinical, radiologic, or serologic evidence of pulmonary disease or autoimmune disorders served as the reference population to judge the positivity of AECA.

Patients with sarcoidosis had a significantly higher positivity rate for and levels of AECA in both serum and BAL fluid than the reference population. In addition, the ER of AECA was significantly elevated in patients with multiple lesions or who required corticosteroid therapy compared with that in patients without multiple lesions or who did not need corticosteroid therapy.

Expression of AECA might be a useful marker to predict the course of sarcoidosis.