Cell-mediated immunity to viral antigens and tuberculin in multiple sclerosis.

Lymphocyte transformation responses to measles, mumps, herpes simplex and parainfluenza virus antigens and purified protein derivative of tuberculin were determined in both 78 normal controls and 40 patients with multiple sclerosis, 16 of whom were studied serially. Patients with multiple sclerosis showed significantly reduced responses to all antigens except herpes simplex. Impaired responses occurred at all stages of clinical activity, but were lowest during recovery from an acute exacerbation or in patients with chronic disease. The transformation responses to measles, mumps and parainfluenza virus antigens correlated significantly with the numbers of circulating T cells, which, similarly, showed parallel fluctuations with disease activity.