Chronic relapsing experimental allergic encephalomyelitis. Inhibition of lymphocyte mitogenesis by disease-related serum factors

Peripheral blood mononuclear cells (PBMC) from strain 13 guinea pigs at various stages of chronic relapsing experimental allergic encephalomyelitis (CREAE) showed significantly reduced reactivity to the polyclonal T cell mitogens, phytohaemagglutinin and concanavalin A. Serum taken at the same time revealed an increase in inhibitors of lymphocyte mitogenesis. The factors identified appeared to inhibit the initial stages of lymphocyte proliferation: they were not cytotoxic for lymphocytes nor were they complement-dependent.