Alpha-fetoprotein suppresses experimental allergic encephalomyelitis.

Experimental allergic encephalomyelitis (EAE), induced in guinea pigs by immunization with myelin basic protein (MBP) or whole CNS homogenate was successfully treated, as well as partially prevented, by daily administration of fetal alpha-fetoprotein (alpha FP). alpha FP which is produced in high quantities during pregnancy can inhibit both the cell-mediated immune response to MBP and the binding of MBP antibody to the antigen in vitro. It has a non-specific immunosuppressive effect on both the cellular and humoral responses. It is suggested that the ability of alpha FP to suppress an experimental autoimmune disease, as presented in this model of EAE, indicates that clinical remissions of human autoimmune disease during pregnancy may be attributed to the effect of this natural substance.