Interferon-beta treated-multiple sclerosis patients exhibit a decreased ratio between immature/transitional B cell subset and plasmablasts.

Our aim was to quantify circulating B cell subsets; immature/transitional, naïve, CD27- and CD27+ memory cells and plasmablasts, in relapsing-remitting multiple sclerosis patients treated with IFN-ß. The most relevant findings were a significant increase of plasmablasts and a decrease of immature/transitional B cells, resulting in a decreased ratio between those cells in relapse RRMS, together with an increase of CD27- and CD27+IgM+ memory B cell subsets in both phases of the disease. These alterations point to an active B cell response, particularly in relapse, and the above referred ratio could constitute a good biomarker of relapse in patients that underwent IFN-ß treatment.