Search for autoantibodies to endothelial and smooth muscle cells in patients with multiple sclerosis.

The blood-brain barrier (BBB) is disrupted in many of the lesions of multiple sclerosis (MS). Immunologically mediated injury to one of the major components of this barrier, the cerebral capillary, may play a role in the development of the lesion. We therefore examined the sera of 51 cases of MS for the presence of autoantibodies to endothelial and smooth muscle cells, using the indirect immunofluorescent technique. The results were compared to those in other groups of patients with neuroimmunological disorders. We found no anti-endothelial cell antibodies, but autoantibodies to vascular smooth muscle were detectable in 31% of the MS sera tested. They were also present, however, in 30% of sera from cases of myasthenia gravis and in the serum of one of 12 cases of polymyositis. It is considered to be unlikely that antibodies to vascular tissues play any pathogenetic role in multiple sclerosis.