Antibodies to proteolipid apoprotein in chronic relapsing experimental allergic encephalomyelitis.

Titers of serum antibodies to proteolipid apoprotein (PLP) were determined in chronic relapsing experimental allergic encephalomyelitis (EAE) of strain 13 guinea pigs sensitized with whole central nervous system tissue. Levels of the antibodies were slightly higher in the animals with relapse than those without relapse during the early chronic stage (days 40-99 postinoculation). The titers were significantly higher in the relapsed animals during the chronic stage (days 100-199). Although the clinical course was polyphasic, the humoral response to PLP was monophasic. Since PLP alone causes chronic EAE with widespread demyelination in guinea pigs (Yoshimura et al. 1985), the high titers of anti-PLP antibodies seem to have something to do with the immunologic mechanisms of chronic relapsing EAE.