Decreased lymphocyte transformation to vaccinia virus in multiple sclerosis.

Lymphocyte transformation to vaccinia virus was measured in multiple sclerosis (MS) patients and normal controls. There was a significant reduction of lymphocyte transformation to vaccinia virus in multiple sclerosis patients compared with the control group. In addition, a positive correlation existed between the degree of disability of the multiple sclerosis patients and the extent of lymphocyte transformation in the presence of vaccinia virus. There was no correlation between cell-mediated immunity to vaccinia virus and either serum or cerebrospinal fluid (CSF) antibody levels to vaccinia in multiple sclerosis patients or controls, all of whom had been previously vaccinated. In conjunction with other studies, all of whom had been previously vaccinated. In conjunction with other studies that have demonstrated elevated antibody titers to vaccinia virus in the CSF of multiple sclerosis patients, these results support the possibility that vaccinia virus may play a role in the pathogenesis of multiple sclerosis.