CD5 + B cells and CD4 −8 − T cells in neuroimmunological diseases

Abstract

Using 2- and 3-colour FACS analysis we found increased levels of fetal-type CD5 + B cells and CD4 −8 − T cells in cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) and aseptic meningitis (AM) compared to control probands with muscular tension headache (TH). Similar differences were found for CD5 + B cells in peripheral blood, but at lower levels. CD4 −8 − T cells in blood exceeded those in CSF in all patient groups, with the exception of relapsing remitting MS, revealing the highest values in AM. There was a positive correlation between CD4 −8 − T cells and T cell receptor (TCR) γδ bearing T cells in blood and CSF. The double-negative T cells exceeded the TCR γδ T cells by about 1%. A positive correlation between CD5 + B cells and CD4 −8 − T cell level in CSF was found in MS and AM, but not in TH, nor in blood of any patient group. HLA-DR expression was lower in CD5 + B cells than in CD5 − B cells. We conclude that fetal-type lymphocytes are enriched in CSF compartment of patients with inflammatory diseases of the central nervous system, irrespective of autoimmune mechanisms involved, but the function of CD5 + B cells is mainly to produce the autoantibodies.