Peripheral CD 24 hi CD 27 + CD 19 + B cells subset as a potential biomarker in naïve systemic lupus erythematosus

Aim B cells are likely to play critical roles in the pathogenesis of systemic lupus erythematosus ( SLE ). Our aim was to investigate the role of peripheral CD 24 hi CD 27 + CD 19 + B cells in C hinese patients with new‐onset SLE . Method Peripheral CD 24 hi CD 27 + CD 19 + B cells were analyzed in 55 new‐onset lupus and 36 healthy controls by flow cytometry. All SLE cases were treated with prednisolone and hydroxychloroquine during a 1‐year follow‐up. Thirteen cases were added with cyclophosphamide or mycophenolate mofetil. The CD 24 hi CD 27 + CD 19 + B cells were analyzed at days 0, 7, 14 and months 1, 3, 6, 9 and 12. Interleukin‐10 ( IL ‐10)‐producing B cell was detected in eight naïve lupus and 10 healthy controls. Results Compared to healthy controls, the frequency and number of primary circulating CD 24 hi CD 27 + CD 19 + B cells was significantly reduced in SLE cases (8.22 ± 3.48% vs . 31.67 ± 5.53%, P <  0.0001; 4.04 ± 2.85 vs . 38.66 ± 10.22 10 3  cells/mL, P  = 0.0001) before treatment; IL ‐10 + CD 19 + B cells and IL ‐10 + CD 24 hi CD 27 + CD 19 + B cells also decreased in SLE . Interestingly, primary CD 24 hi CD 27 + CD 19 + B cells inversely correlated with SLE disease activity index ( SLEDAI ) score. Patients with arthritis and hematologic disorders had a lower primary CD 24 hi CD 27 + CD 19 + B cells. In 48 SLE cases who finished the 1‐year follow‐up, the frequency and number of CD 24 hi CD 27 + CD 19 + B cells increased from 8.26 ± 3.61% to 25.51 ± 4.56%; 3.99 ± 2.86 to 28.64 ± 11.81 10 3 cells/mm 3 ( P <  0.0001), accompanied by a significantly decreased SLEDAI score. Of note, CD 24 hi CD 27 + CD 19 + B cells decreased in some flare cases with an elevated SLEDAI score. Conclusion These results demonstrate that a lower primary CD 24 hi CD 27 + CD 19 + B cells may be an immunologic aspect of new‐onset SLE . CD 24 hi CD 27 + CD 19 + B cells may be a useful tool to evaluate lupus activity and monitor the response to therapy.