Immunologic and virologic studies of measles inclusion body encephalitis in an immunosuppressed host: the relationship to subacute sclerosing panencephalitis.

An immunosuppressed child with acute lymphoblastic leukemia in clinical remission developed measles inclusion body encephalitis (MIBE). Although measles antigen and nonbudding measles virus nucleocapsids were detected in brain tissue, no virus was isolated. Immune precipitation of measles virus proteins with the patient's serum showed no detectable antibody to virus M protein, a finding that has been reported in subacute sclerosing panencephalitis (SSPE). The virologic and immune precipitation studies suggest a similar virus mutation in MIBE and SSPE. The pathogenesis of the two diseases may also be similar.