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.