Anti-T cell activity of niridazole in experimental autoimmune encephalomyelitis.

The antischistosomal drug niridazole, known to selectively depress cell-mediated immune function, was assessed in experimental autoimmune encephalomyelitis (EAE) in mice. EAE results from an immune attack by activated T lymphocytes on the central nervous system. Niridazole given orally at a dose of 100 mg/kg body weight three times a week and starting either before or after immunization caused a significant suppression of signs and histological lesions of EAE, lasting up to ten weeks after cessation of treatment. There was no effect of niridazole on either release of macrophage migration inhibition factor in response to specific neural antigen, production of antibody, or on the nonspecific inflammatory reaction to adjuvant. Niridazole presumably acts by preventing release of lymphokines by activated T cells after contact with antigens.