Cellular immunoregulatory mechanisms in the central nervous system: characterization of noninflammatory and inflammatory cerebrospinal fluid lymphocytes.

Dual-label flow cytometric analysis of cerebrospinal fluid (CSF) and blood lymphocytes with combinations of monoclonal antibodies such as CD4 plus CD45R or Leu8, and CD8 plus CD11b was performed in 37 patients with noninflammatory neurological diseases (NINDs) to clarify the differences in cellular immunoregulatory mechanisms present in the central nervous system (CNS) and in the systemic circulation. In the CSF of patients with NINDs, the paucity of CD4+CD45R+ and CD8+CD11b+ cells was striking, whereas the same subsets accounted for substantial proportions in the blood. CD4+CD45R- and CD4+Leu8- cells as well as CD8+CD11b- cells increased in the CSF when compared with those in the blood. Seven patients with active multiple sclerosis (MS) and 10 patients with other inflammatory diseases in the CNS (CNS-infl) were also studied. Patients with active MS were characterized by a consistent increase in percentage of CD4+CD45R- cells in the CSF, whereas an increase of CD4- CD45R+ cells in the CSF was a feature of the patients with CNS-infl, when compared with patients with NINDs. These findings indicate that the CNS is routinely surveyed by particular subsets of lymphocytes different from those in the blood, and cellular immune reaction in the CNS varies according to the types of CNS inflammatory conditions.