Normal T cell subsets and lymphocyte activity in multiple sclerosis.

Nine patients with either chronic progressive or relapsing/remitting multiple sclerosis were treated with several courses of lymphopheresis. The lymphocytes obtained by this procedure showed a significantly lower percentage of OKT3+ cells than normal controls at the beginning of therapy. This percentage increased to normal levels after five lymphopheresis treatments and then decreased during the last stages of treatment. Patients had normal levels of OKT4+ and OKT8+ cells compared to controls and these percentages showed no statistically significant changes during the course of treatment. The proliferative response of patient's lymphocytes after stimulation with concanavalin A, PHA and alloantigen was not significantly different from normal controls and these responses were unchanged during the lymphopheresis treatment. Natural killer cell activity was also normal in our patients. The results reported in this study do not suggest a basic T cell abnormality in our patients with multiple sclerosis. Furthermore, the lymphopheresis treatments did not induce any significant change in T cell numbers or functional activity in vitro.