Peripheral blood B and T-lymphocyte populations in patients with multiple sclerosis. Relationship with clinical activity of the disease and chronic immunosuppressive treatment.

During a period of 30 months, we studied the proportions of B and T cells, and of T cell subpopulations, in 924 blood samples from 213 MS patients. The disease was clinically stable in 88 patients (271 samples), relapsing progressive in 50 (349 samples), slowly progressive in 71 (262 samples) and in acute, selfremitting relapses for 31 patients (42 samples). By comparison with controls, untreated MS patients displayed a slightly higher percentage of B-cells (p less than 0.05) and a striking decrease of the mean percentage of CD8 + cells (p less than 0.001). Within the MS group, patients with an active disease presented a more marked decrease of the number of CD8 + cells and an increase of the CD4/CD8 ratio (p less than 0.01). However, 13 out of the 88 clinically stable patients had persistently high CD4/CD8 ratios, whereas such a high ratio was observed only in 60% of samples collected during an acute relapse. Eighty patients with a progressive form of the disease were chronically treated by immunosuppressive drugs, usually cyclophosphamide (N = 69). This treatment induced within one year a marked decrease of the absolute number of B and CD4 + cells, and a return to normal values of the CD4/CD8 ratio.