Endothelial cell damage in sarcoidosis and neurosarcoidosis: autoantibodies to endothelial cells.

Damage to the vascular system, of which endothelial cells are the main constituent, may occur in sarcoidosis. Evidence of blood-brain barrier (BBB) disruption is shown in sarcoidosis with central nervous system (CNS) involvement by means of magnetic resonance imaging or computed tomography. We investigated the presence of antiendothelial cell antibodies by culture of endothelial cells derived from human umbilical cord vein and from human brain using an enzyme-linked immunosorbent assay, and the presence of circulating immune complexes using a Raji cell assay, in the sera of patients with sarcoidosis. The patients with sarcoidosis displayed significantly high levels of immunoglobulin G (IgG) binding to endothelial cells after blocking Fc receptor compared to controls (p < 0.01). The sera of neurosarcoid patients with CNS involvement still showed significantly increased levels of IgG binding to brain endothelial cells after blocking Fc receptor compared to controls and those of pulmonary sarcoidosis (p < 0.001 and p < 0.01 respectively). These results suggest that the presence of autoantibodies to endothelial cells may be involved in endothelial cell damage, including BBB disruption.