Joseph E. Smadel Memorial Lecture: neuroimmunologic diseases of animals and humans.

New precepts gained from the crescendo of neuroimmunobiologic research of recent decades have increased our understanding of experimental allergic encephalomyelitis (EAE), virus-associated acute disseminated encephalomyelitis (ADE), and multiple sclerosis (MS). EAE of animals and humans provides evidence of the existence in mammalian lymphoid tissues of potential clones of cells with autoreactivity for myelin basic protein (MBP) and other antigenic constituents of the central nervous system (CNS). In a new hamster model, EAE has been strikingly potentiated by persistent infection of the CNS with defective measles virus, a finding that also has implications for virus-associated ADE. Endogenous MBP or MBP degradation fragments, reactive with MBP antibodies of various affinities, have been detected by a recently devised radioimmunoassay in serum, plasma, and other body fluids of normal rats, rats with EAE, and patients with virus-associated ADE or MS. Circulating MBP or MBP fragments may be of great importance in inhibiting neuroautoimmune reactivity and play a role in repair of immunologic CNS injury should it inadvertently occur. Finally, the impressive degree of concordance of immunologic events in EAE, virus-associated ADE, and MS provides additional support for the central importance of host neuroimmunologic responses in the pathogenesis of these neutologic diseases.