Cellular transfer of experimental allergic encephalomyelitis: Altered disease pattern in irradiated recipient Lewis rats

Irradiation of recipient Lewis rats 6–24 hr prior to injection of sensitized lymph node cells (LNC) altered the pattern of transferred experimental allergic encephalomyelitis (EAE). Recipients subjected to total body irradiation in doses ranging from 500 to 1000 rads developed paralysis; nonirradiated control recipients did not do so. Histopathologic changes of EAE, in terms of number of descrete cellular infiltrates, were potentiated in the total body irradiated recipients. Among LNC recipients subjected to regional irradiation (850 rads) of the head or lower spinal column, paralysis was observed only in those animals where the irradiation impinged upon the spinal cord. Cellular infiltrates of EAE were numerically more common in the irradiated region of the neuraxis. The findings are discussed in terms of irradiation rendering the central nervous system of animals and man more vulnerable to autoimmune injury.