Expression of CCR7 and CD45RA in CD4 ⁺ and CD8 ⁺ subsets in cerebrospinal fluid of 134 patients with inflammatory and non-inflammatory neurological diseases

We investigated CD45RA and CCR7 expression in CD4 ⁺ and CD8 ⁺ subsets of cerebrospinal fluid (CSF) lymphocytes, both immediately ex vivo and after stimulation, from 134 patients with a variety of inflammatory and non-inflammatory neurological diseases. Most inflammatory diseases had a higher CD4 ⁺:CD8 ⁺ ratio and higher percentage of effector memory T cells (T _EM) than non-inflammatory controls, excluding active infection. Moreover, we found that patients with highly elevated cell counts in the CSF tended to have a lower percentage of central memory T cells (T _CM) than patients with low or absent pleocytosis, with a concomitant increase in T _EM. We also found that samples with elevated IgG index or presence of oligoclonal bands had a significantly higher CD4 ⁺:CD8 ⁺ ratio than normal samples, consistent with increased CD4 ⁺ help for intrathecal IgG synthesis by B cells.