Autoantibodies to each protein fraction extracted from cerebral endothelial cell membrane in the sera of patients with multiple sclerosis

Damage to the blood-brain barrier (BBB) occurs in multiple sclerosis (MS), probably due to an immunological mechanism. Anti-endothelial cell antibodies may play a pathogenetic role in the BBB damage. Our previous studies led us to search for which protein fraction extracted from cerebral endothelial cell membrane was reactive to antibodies in the sera of patients with MS. The antibodies to each protein fraction extracted from the rat cerebral endothelial cell membrane were studied in patients with MS, other neurological diseases and controls using an enzyme-linked immunosorbent assay (ELISA) method. The patients with active relapsing MS ( P < 0.01) displayed significantly higher levels of immunoglobulin G (IgG) binding to the endothelial cell membrane fraction than did the controls. The sera of the same patients ( P < 0.001) also showed significantly higher levels of antibodies to fraction I (8.0 kDa) than did the normal controls. The high levels of IgG binding to fraction II (11.0 kDa) and III (12.3 kDa) were significantly increased in the sera of patients with active relapsing MS compared to normal controls ( P < 0.01). The immune response to the protein fraction extracted from the cerebral endothelial cell membrane fraction may indicate a result of the BBB damage in the case of MS.