Optimum conditions for inducing chronic relapsing experimental allergic encephalomyelitis in guinea pigs.

The aim of this study was to investigate some of the conditions required for the consistent production of chronic relapsing experimental allergic encephalomyelitis (EAE). The concentration of mycobacterium/antigen was found to be a critical factor in producing relapses. Of the 3 antigens used to produce EAE--myelin, myelin basic protein (MBP) and whole spinal cord--only the latter produced a relapsing-remitting EAE. F1 crosses between female Hartley and male Strain 13 guinea pigs displayed an identical relapsing pattern to that of juvenile Strain 13 animals. The frequency of relapses was increased in Hartley guinea pigs when injected over the nuchal region.