Experimental allergic encephalomyelitis (EAE) in two inbred guinea pigs: 1. Strain differences in developing chronic relapsing form of EAE.

Two inbred strains of guinea pig (Strain 13 and JY-1) were compared with regard to their reactivity to the central nervous tissue emulsion in complete Freund's adjuvant as the challenge for elicitation of EAE. The susceptibilities to EAE sensitization of adult guinea pigs were almost equal between the two strains, while those of young animals were different. The young Strain 13 guinea pigs are liable to develop chronic relapsing form of EAE, the incidence is 100% in 4--5 weeks guinea pigs and 60% in 6 weeks. On the contrary young JY-1 guinea pigs were as susceptible as adults. They developed typical acute EAE, which was usually fatal. Central nervous system of acute and chronic EAE guinea pigs of two strains was examined by the indirect immunofluorescent technique for the detection of lymphocytes. Most of the positive lymphocytes were detected in the perivascular space and some were detected in the parenchyma of the brain.