The imbalance in CSF T cell subsets in active multiple sclerosis.

We determined the percentage of each lymphocyte subpopulation in the cerebrospinal fluid (CSF) and the peripheral blood of 7 patients with active multiple sclerosis (MS), 7 with inactive MS, 5 with other inflammatory diseases in the central nervous system, and 12 with non-inflammatory neurological diseases, using fluorescein-labelled monoclonal antibodies (anti-Leu7, anti-HLA-DR, and those that recognize such surface antigens as CD3, CD4, CD8, and CD19), and by laser flow cytometry to clarify the clinical usefulness of their measurement in the assessment of disease activity in MS. In CSF, a significant increase in the percentage of CD4+ cells and a significant decrease in the percentage of CD8+ cells were observed in the active MS group compared with the other 3 groups, while none of the percentages of the 6 subsets studied in the peripheral blood were significantly different among these groups. Our preliminary study indicated that evaluation of the percentages of CD4+ and CD8+ cells in CSF by flow cytometry could be a useful indicator of disease activity in MS.