Total body irradiation allows reinduction of allergic encephalomyelitis in convalescent Lewis rats.

The ability of total body irradiation to alter recovery from and development of acquired resistance to allergic encephalomyelitis has been studied in Lewis rats. Irradiation before sensitization inhibits disease production, whereas irradiation after sensitization has no effect. In the latter situation animals recover from disease in a normal fashion. The generation of resistance to reinduction of disease is not affected by irradiation given either before or after the primary sensitization. However, irradiation given after both the primary and secondary challenges allows the development of a secondary disease episode. Studies on antibodies against basic protein in such treated animals suggest that antibodies play a role in resistance to reinduction of disease.