T-cell subpopulations in blood and cerebrospinal fluid of multiple sclerosis patients: effect of cyclophosphamide.

Monoclonal antibodies to various lymphocyte surface antigens were used for characterization of cerebrospinal fluid (CSF) and peripheral blood (PB) cells of patients with chronic progressive multiple sclerosis (MS) and of patients with other neurological diseases (OND). The effect of cyclophosphamide on these T-lymphocyte subpopulations in both compartments was studied. In the CSF of all patients 90 +/- 9% of the cells were T lymphocytes. T-helper/inducer (Th) lymphocytes comprised 70 +/- 9% and T-suppressor/cytotoxic (Ts) lymphocytes 31 +/- 10%. No significant differences in the percentages of T-lymphocyte subpopulations in CSF were observed between MS patients and patients with OND. The results obtained with monoclonal antibodies to Ia antigens suggested the presence of activated T cells in CSF of MS as well as OND patients. The mononuclear cell population isolated from PB of all patients contained 64 +/- 13% T lymphocytes, 44 +/- 11% Th cells, and 21 +/- 7% Ts cells. No significant difference in the ratio Th/Ts cells was observed between CSF and PB. The mononuclear cells isolated from the PB of untreated chronic progressive MS patients contained lower percentages of Ts cells (17 +/- 5%) and increased ratios of Th/Ts cells (3.1 +/- 1.6) compared to neurological controls (23 +/- 8% and 1.9 +/- 0.7) and healthy persons (23 +/- 6% and 1.9 +/- 0.5). In both PB and CSF, compared to untreated patients, cyclophosphamide-treated MS patients showed lower percentages of Th lymphocytes, whereas Ts-cell percentages were higher, leading to a normal ratio of Th/Ts cells in both compartments. The percentage of total T lymphocytes in PB was reduced by this treatment.