A higher frequency of CD4+ CXCR5+ T follicular helper cells in patients with newly diagnosed Henoch–Schönlein purpura nephritis

Abstract

T follicular helper (TFH) cells play an important role in the humoral immune responses. The aim of this study was to examine the frequency of different subsets of CD4+CXCR5+ TFH cells and B cells in patients with new-onset Henoch–Schönlein purpura nephritis (HSPN). The numbers of different subsets of CD4+CXCR5+ TFH cells, B cells and the constituents of serum cytokines were detected in a total of 25 patients with newly diagnosed HSPN before and after treatment, and in 14 healthy controls (HC). The potential connection of these cells with the clinical characteristics in HSPN patients was analyzed. The numbers of circulating CD4+CXCR5+, CD4+CXCR5+ICOS+ and CD4+CXCR5+PD-1+ TFH cells, CD86+CD19+, CD38+CD19+ B cells and serum IL-2, IL-4, IL-17A, IL-21 and IFN-γ were significantly higher in HSPN patients (p<0.05) than in HC. Before and after treatment the numbers of CD4+CXCR5+ TFH cells were negatively correlated with the values of eGFR (r=−0.7162, p<0.05; r=−0.732, p<0.05, respectively). Similarly the numbers of CD4+CXCR5+PD-1+ TFH cells were negatively correlated with 24-h urinary proteins (r=−0.4013, p<0.05; r=−0.7857, p<0.05, respectively), and the numbers of CD4+CXCR5+ICOS+ TFH cells were positively correlated with the levels of serum IL-21 (r=0.5186, p<0.05; r=0.8503, p<0.05, respectively) and 24-h urinary protein (r=0.6045, p<0.05; r=0.833, p<0.05, respectively) in these patients, regardless of treatment. Following treatment the numbers of CD4+CXCR5+, CD4+CXCR5+PD-1+, and CD4+CXCR5+ICOS+ TFH cells, as well as serum levels of IL-21 were significantly reduced, however IL-4 levels were noticeably increased (p<0.05). A higher frequency of circulating CD4+CXCR5+ TFH cells existed in patients with HSPN and may be a viable therapeutic target.