Autoantibodies to brain endothelial cells in the sera of patients with human T-lymphotropic virus type I associated myelopathy and other demyelinating disorders.

We examined the sera of 21 cases of human T-lymphotropic virus type I (HTLV-1)-associated myelopathy (HAM), 30 cases of neuro-Behçet (N-B) syndrome, and 36 cases of multiple sclerosis (MS) for the presence of autoantibodies to brain endothelial cells by enzyme-linked immunosorbent assay (ELISA) using cultured brain endothelial cells. The concentrations of immunoglobulin G (IgG) which bound to brain endothelial cells were significantly increased in the sera of patients with HAM before (P less than 0.001) and after (P less than 0.01) blocking Fc receptors compared to those of controls. The levels of IgG binding to brain endothelial cells were also significantly increased in the sera of patients with N-B syndrome (P less than 0.01), and MS (P less than 0.001) especially those in an exacerbation compared to those of controls regardless of blocking Fc receptors. These results suggest that IgG binding to brain endothelial cells may be mediated via an immunologically specific antigen-antibody interaction as a result of the blood-brain barrier (BBB) damage in cases of HAM, N-B syndrome and MS.