Hypersensitivity to human brain S-100 protein in chronic alcoholics.

We have studied hypersensitivity to neurotissue in alcoholics. Fifty-four male chronic alcoholics with signs of mental deterioration, and 30 age-matched healthy male subjects were skin tested with human S-100 brain protein and liver protein, and protein purified derivate of tuberculin (PPD). The local Arthus and delayed sensitivity reactions were read at 4 hr and 24-48 hr respectively. Alcoholics and non-alcoholics exhibited a similar capacity to develop Arthus and delayed hypersensitivity to PPD. However, of all patients, 98.1% developed positive Arthus and 96.3% delayed skin reactions to S-100 protein, whereas 27.7% developed Arthus and 43.3% delayed reactions to liver protein. In non-alcoholics, the frequency of hypersensitivity reactions to S-100 protein and liver protein was low. The very high incidence of Arthus and delayed hypersensitivity reactions to a brain antigen in chronic alcoholics suggests that both humoral and cell-mediated immunity are involved in the pathogenesis of alcohol-induced brain damage.