Chronic relapsing experimental allergic encephalomyelitis in strain 13 guinea pigs; presence of myelin basic protein in the local tissue long after the immunization.

In order to obtain a clue to understand the induction mechanism of chronic form of EAE we studied the immunized site of EAE animals with immunocytochemical techniques. There were numerous vacuoles associated with inflammatory reactions in the subcutaneous tissue of immunized feet. Immunocytochemical staining with antiserum to myelin basic protein (MBP) disclosed remaining of MBP in and around the vacuoles. The MBP remained more in early stage and less in chronic stage; it remained even on 326th day of postimmunization. A possible role of the remained antigen in chronic EAE was discussed.