Profiles of peripheral B cell subsets in a cohort of primary Sjögren's syndrome patients and their potential clinical significance

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^highCD38^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^hiCD27⁺ 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.