Characterization of naïve, memory and effector T cells in progressive multiple sclerosis.

We characterized naïve, central memory (CM), effector memory (EM) and terminally differentiated effector memory (TEMRA) CD4+ and CD8+ T cells and their expression of CD49d and CD26 in peripheral blood in patients with multiple sclerosis (MS) and healthy controls. CD26+ CD28+ CD4+ TEMRA T cells were increased in all subtypes of MS, and CD26+ CD28+ CD8+ TEMRA T cells were increased in relapsing-remitting and secondary progressive MS. Conversely, in progressive MS, CD49d+ CM T cells were decreased and natalizumab increased the circulating number of all six subsets but reduced the frequency of most subsets expressing CD49d and CD26.