Reduced peripheral blood regulatory B cell levels are not associated with the Expanded Disability Status Scale score in multiple sclerosis

Objective To investigate levels of regulatory B (Breg) cells, plasma cells, and memory B cells in the peripheral blood, and interleukin (IL)-10 in the serum of multiple sclerosis (MS) patients, and to determine the correlation between Breg cell levels and the Expanded Disability Status Scale (EDSS) score. Methods Levels of Breg cells, plasma cells, and memory B cells in the peripheral blood of 12 MS patients were measured using flow cytometry. IL-10 serum levels were measured by enzyme-linked immunosorbent assay. The correlation between Breg cell levels and MS EDSS score was measured using Pearson's correlation coefficient. Results Compared with healthy controls, MS patients had decreased levels of CD19(+)CD24(hi)CD38(hi) Breg cells in their peripheral blood and reduced serum levels of IL-10; however, the ratios of CD19(+)CD27(hi)CD38(hi) plasma cells and CD19(+)CD27(+)CD24(hi) memory B cells to total B cells did not differ significantly between healthy controls and MS patients. CD19(+)CD24(hi)CD38(hi) Breg cell levels in the peripheral blood of MS patients were not significantly correlated with MS EDSS score. Conclusion Peripheral blood CD19(+)CD24(hi)CD38(hi) Breg cell levels and serum IL-10 levels were reduced in MS patients compared with controls, but Breg cell levels were not correlated with MS EDSS score.