Peripheral CD24hiCD27+CD19+B cells subset as a potential biomarker in naive 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 CD24(hi)CD27(+)CD19(+)B cells in Chinese patients with new-onset SLE. Method: Peripheral CD24(hi)CD27(+)CD19(+)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 CD24(hi)CD27(+)CD19(+)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 naive lupus and 10 healthy controls. Results: Compared to healthy controls, the frequency and number of primary circulating CD24(hi)CD27(+)CD19(+)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(+)CD19(+) B cells and IL-10(+)CD24(hi)CD 27(+)CD19(+)B cells also decreased in SLE. Interestingly, primary CD24(hi)CD27(+)CD19(+)B cells inversely correlated with SLE disease activity index (SLEDAI) score. Patients with arthritis and hematologic disorders had a lower primary CD24(hi)CD27(+)CD19(+)B cells. In 48 SLE cases who finished the 1-year follow-up, the frequency and number of CD24(hi)CD27(+)CD19(+)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, CD24(hi)CD27(+)CD19(+)B cells decreased in some flare cases with an elevated SLEDAI score. Conclusion: These results demonstrate that a lower primary CD24(hi)CD27(+)CD19(+)B cells may be an immunologic aspect of new-onset SLE. CD24(hi)CD27(+)CD19(+)B cells may be a useful tool to evaluate lupus activity and monitor the response to therapy.