CD19 + CD24 high CD27 + B cell and interleukin 35 as potential biomarkers of disease activity in systemic lupus erythematosus patients

Background Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that associates with aberrant activation of B lymphocytes and excessive autoantibodies. Interleukin 10 (IL-10)/interleukin 35 (IL-35) and IL-10/IL-35-producing regulatory B cells have been demonstrated to possess immunosuppressive functions during systemic lupus erythematosus. Here, we detected the proportion of CD19 + CD24 high CD27 + B cells as well as IL-10 and IL-35 levels in peripheral blood of SLE patients and healthy individuals, and investigated their relations with clinical features of SLE. Methods 41 SLE patients and 25 healthy controls were recruited. The patients were divided into groups based on SLEDAI score, anti-dsDNA antibody, rash, nephritis and hematological disorder. Flow cytometry was used to detect the proportion of CD24 hi CD27 + B cells. ELISA was used to detect serum levels of IL-10 and IL-35. Results Our results showed that the CD19 + CD24 high CD27 + B population was decreased in active SLE patients, and anti-correlated with the disease activity. Of note, we found significant increase of IL-10 and decrease of IL-35 in SLE patients with disease activity score > 4, lupus nephritis or hematological disorders compared to those without related clinical features. Conclusions Reduced CD19 + CD24 high CD27 + B cells expression may be involved in the pathogenesis of SLE. Moreover, we supposed that IL-35 instead of IL-10 played a crucial role in immune regulation during SLE disease.