Abstract
BACKGROUND/PURPOSE: Primary Sjögren's syndrome is a prototypical autoimmune disease, with B cell dysfunction as a dominant feature. Further insights into distribution of B cell subsets in primary Sjögren's syndrome are urgently required to identify the most appropriate target subpopulation. We aimed to evaluate the profiles of B lymphocyte subpopulations in primary Sjögren's syndrome patients and to investigate their clinical significance. MATERIALS AND METHODS: Thirty primary Sjögren's syndrome patients and 15 age-and sex-matched healthy controls were recruited. Peripheral B cell subsets were analyzed by flow cytometry. RESULTS: Compared to healthy controls, circulating CD19(+) B cells, CD19(+)CD20(-) B cells, CD19(+)CD27(-)IgD(+) naïve B cells, CD19(+)IgD(+)CD38(high) plasmablasts, CD19(+)CD24(high)CD38(high) transitional B cells and CD19(+)CD20(-)CD27(+)CD38(+) plasma cells were elevated in patients with primary Sjögren's syndrome, whereas CD19(+)CD27(+) memory B cells, CD19(+)CD27(-)IgD(-) double negative B cells and CD19(+)CD24(hi)CD27(+) Bregs were decreased. Furthermore, the percentage of circulating CD19(+)CD20(-)CD27(+)CD38(+) plasma cells was positively correlated with serum IgG levels and the proportional area of lymphocytic infiltration of labial gland. CONCLUSION: We identified a comprehensive B lymphocyte subset distribution profile in primary Sjögren's syndrome. Moreover, we detected a clinical significance of CD19(+)CD20(-)CD27(+)CD38(+) plasma cells, suggesting that these cells might play a key role in disease pathology and represent potential therapeutic targets.