Regulatory B cells in autoimmune rheumatic diseases

BACKGROUND: Regulatory B cells (regulatory B cells, Breg cells) in recent years have been shown to be important immunoregulatory factors. AIM: To review the role of Breg cells in autoimmune rheumatic diseases. METHODS: This descriptional review was carried out after research on PubMed using the keywords “Bregs and rheumatoid arthritis”, “systemic lupus erythematosus”, “Sjögren’s syndrome”, “systemic sclerosis”, “vasculitis”, and “dermatomyositis”. RESULTS: Breg cells have an inhibitory effect on pro-inflammatory Th1 and Th17 cells and prevent the development of autoimmune diseases. Breg cells mediate their effects through interleukin-10 (IL-10, IL-10+Breg cells), but recently other Breg cells have been recognized that mediate their effects through IL-35 (IL-35+Breg cells), or through transforming growth factor-β (TGFβ, TGFβ+Breg cells). In experimental models of autoimmune diseases, Breg cells are decreased, and when expanded ex vivo and re-infused back into animals, they ameliorate disease. In humans, IL-10+Breg cells are decreased in active autoimmune diseases, such as rheumatoid arthritis, ANCA-associated vasculitis, and systemic sclerosis, and may increase to normal levels in disease remission. CONCLUSIONS: The deficiency of IL-10+Breg cells during active autoimmune rheumatic disease suggests that Breg cells may be used as biomarkers and be a possible therapeutic target in these diseases.