Role of the vascular endothelial cell antigen system in the etiology of atherosclerosis.

An autoantibody directed against an antigen system that is expressed on the vascular endothelial cell (VEC) was recently identified in random patients with peripheral vascular disease. This VEC antigen system is also present on the peripheral blood monocyte but not on any other cell type studied to date. In a randomized study of 112 patients with peripheral vascular disease at the Albany Medical College, 46% demonstrated an autoantibody against their autologous monocytes and VEC. This autoantibody is a highly cytotoxic, complement-fixing antibody directed against VEC antigens. It does not crossreact with autologous T or B lymphocytes and appears to be highly polymorphic. It is present in only nine per cent of the age-matched controls and was never detected in young controls. This preliminary investigation suggests that immunological injury may be the initiating factor in the development of atherosclerotic lesions more frequently than currently appreciated. Whether this autoantibody to VEC is the result of or the cause of endothelial cell damage in these patients is still under study.