Cellular immune response to measles, mumps, and vaccinia viruses in multiple sclerosis.

The cell-mediated immune response to measles, mumps, and vaccinia viruses was studied in MS patients, normal controls, and neurological disease controls using a lymphocyte proliferation assay. A small but significant difference was found in the response to measles between the MS and normal control groups but not between the MS and neurological disease control groups. In each of the groups, the response of both peripheral blood leukocytes and purified T-cells to measles was significantly less than the response to mumps or vaccinia. The lower response to measles was not due to the presence of blocking factors or to lack of antigenicity of the measles virus preparation used in the assay. These findings suggest that differences exist in the normal immune response between these viruses. Precise quantitation of the immunological response to viruses in MS and other disease states will depend on identification of the various functionally reactive cell populations.