Serum anti-GFAP and anti-S100 autoantibodies in brain aging, Alzheimer's disease and vascular dementia.

Autoantibodies against glial fibrillary acidic protein (GFAP) and S100 protein were measured in sera of patients suffering from vascular dementia (VD), presenile Alzheimer's disease (AD), senile Alzheimer's disease (SDAT) and aged healthy controls by means of ELISA test. VD and SDAT showed the highest levels of both autoantibodies, AD the lowest. From these results a relationship between autoantibody titers and aging seems possible. Dosage of anti-GFAP and anti-S100 autoantibodies does not appear useful for diagnostic purpose because of the overlap observed among groups. Rather, the presence of these antibodies seems to reflect an alteration of the blood-brain barrier that promotes the access of central nervous system antigens to immunocompetent cells.