Dimethyl fumarate alters B‐cell memory and cytokine production in MS patients

We evaluated the effect of dimethyl fumarate (DMF) treatment on B‐cell memory and cytokine production in 18 patients with relapsing remitting multiple sclerosis (RRMS) using peripheral blood mononuclear cells obtained prior to and at 6 months post‐DMF initiation. We noted a decline in the absolute B‐cell number with DMF treatment, with a preferential depletion of memory B cells and a concurrent increase in naïve B cells. We noted significant reductions in GM‐CSF, TNF‐α, and IL‐6 producing B cells with DMF treatment. These effects on the B‐cell compartment may underlie the beneficial effects of DMF in RRMS.