Increased Interleukin 21 and Follicular Helper T-like Cells and Reduced Interleukin 10+B cells in Patients with New-onset Systemic Lupus Erythematosus

Objective. To elucidate the potential role of follicular helper T cells (TFH) and interleukin 10 (IL-10)+ B cells in the development of systemic lupus erythematosus (SLE). Methods. The numbers of peripheral blood CD27+, CD38+, CD86+, CD95+, IL-10+ B cells, and inducible T cell costimulator (ICOS)+, programmed death-1 (PD-1)+, IL-21+, CXCR5+CD4+ TFH-like cells were examined in 23 patients with new onset SLE and 20 healthy controls (HC). Results. In comparison with HC, significantly reduced numbers of CD19+ and IL-10+ B cells, but increased numbers of CD27(high), CD86+, CD95+ B cells, CXCR5+CD4+, ICOS+, PD-1+, and IL-21+ TFH-like cells were detected, which were accompanied by higher levels of serum IL-21, but lower levels of IL-10 in the patients. Treatment with anti-SLE therapy modulated the imbalance of different subsets of B and TFH-like cells. The levels of serum IL-21 and IL-10 were positively correlated with the numbers of CD4+CXCR5+ TFH-like and CD19+CD5+CD1d+ B cells in the patients, respectively. The numbers of CD27(high) B cells were correlated positively with IL-21+ TFH-like cells, but negatively with IL-10+ B cells. The values of SLE Disease Activity Index, C3, and erythrocyte sedimentation rate were correlated positively with serum IL-21, but negatively with IL-10 in those patients. Conclusion. Our data indicate that the imbalance of IL-21+ TFH-like, CD27(high), and IL-10+ B cells may be associated with the pathogenesis of SLE, and levels of serum IL-21 and IL-10 may be valuable for evaluating disease activity in SLE.