Reduction in IL-10 producing B cells (Breg) in multiple sclerosis is accompanied by a reduced naive/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 naive Bregs. We found no correlation between vitamin D status and B cell subsets. An effect of vitamin Don Bregs cannot be ruled out, since it might be the function that is interfered with instead of relative numbers. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.