Delayed, relapsing experimental allergic encephalomyelitis in mice.

Immunization of female SJL mice with an emulsion of lyophilized mouse spinal cord, pertussis vaccine, and complete Freund's adjuvant produces a delayed and often relapsing form of experimental allergic encephalomyelitis (DR-EAE). The mice develop initial signs of disease an average of 6 mo after immunization. Relapses occurred 2 wk to 11 mo after the initial illness. Some animals had multiple relapses. Pathologic examination of the brain and spinal cord revealed perivascular infiltration of mononuclear cells with acute demyelination. Areas of subacute and chronic demyelination ("plaques") were also seen. This model produces a clinical course of relapsing-remitting disease with pathologic evidence of both recent and old inflammatory lesions at various levels of the central nervous system. It thus more closely resembles multiple sclerosis than acute EAE.