CSF mononuclear cell subsets in active MS: lack of disease-specific alteration

We studied CSF mononuclear cell subsets in MS and acute aseptic meningoencephalitis, using seven monoclonal antibodies. Ia-bearing cells were more frequent in active MS than in stable MS. In active MS, the percentage of Ia-bearing cells was higher than M5 cells or B7 cells, suggesting that Ia-positive T cells appear when the disease is active. However, there was no difference in the proportion of CSF cell subsets in active MS and acute aseptic meningoencephalitis; the changes in MS are similar to acute inflammatory reactions.