LAUSR

The frequency of CD20+ T cells was reported to be increased in several inflammatory conditions. We report that in patients with multiple sclerosis (MS), CD20+ T cells display a distinct proinflammatory phenotype with pathogenic properties. Anti‐CD20 treatment virtually extinguished CD20+ T cells, which might explain its broad effectiveness. Dimethyl fumarate dampened activity of differentiated CD20+ T cells, whereas fingolimod reduced their abundance only as part of its overall T cell suppressive capacity. Natalizumab increased the frequency of CD20+ effector T cells. Widely used MS therapeutics affect this proinflammatory T cell subset with assumed pathogenic potential in a surprisingly differential manner. ANN NEUROL 2021 ANN NEUROL 2021;90:834–839