Reduction in IL-10 producing B cells (Breg) in multiple sclerosis is accompanied by a reduced naïve/memory Breg ratio during a relapse but not in remission.

In this study, we assessed B cell subsets, including Bregs, during stable and active disease in relapsing remitting multiple sclerosis (RRMS) patients and related B cell subsets to vitamin D status. We report that RRMS patients have a decreased percentage of both memory B cells and Bregs compared to healthy controls. During a relapse, the reduction in Bregs involved in particular naïve Bregs.

Effect of vitamin D(3) supplementation on peripheral B cell differentiation and isotype switching in patients with multiple sclerosis.

Background: Vitamin D has been proposed as a promoter of immune homeostasis in multiple sclerosis (MS). During the past decade, the focus of the effects of vitamin D has been on dendritic cells and on T cells. Since there is an increasing interest in the role of B cells in the pathophysiology of MS, we studied the role of vitamin D on B cells in vivo in patients with MS.