A higher frequency of CD4+CXCR5+ T follicular helper cells in patients with newly diagnosed IgA nephropathy

• The frequencies of CD4+CXCR5+ TFH cells were higher in IgAN patients.
• Treatment with prednisone significantly reduced TFH cells in IgAN patients.
• Pro-inflammatory Th1 and Th17 responses were enhanced in IgAN patients.
• TFH cells can regulate humoral immune responses in IgAN patients.
• TFH cells may be new targets for intervention of IgAN.

The frequency of different subsets of CD4+CXCR5+ TFH cells and the levels of serum cytokines were examined in 24 patients with newly diagnosed IgAN before and 8–12 weeks after treatment and in 12 healthy controls (HC). In comparison with HC, significantly higher percentages of CD4+CXCR5+, CD4+CXCR5+ICOS+, CD4+CXCR5+PD-1+ TFH cells and higher levels of serum IL-17A, IFN-γ, IL-2, IL-10, IL-4 and IL-21 were detected in IgAN patients. The percentages of CD4+CXCR5+ TFH cells were negatively correlated with the values of eGFR and CD4+CXCR5+PD-1+ TFH cells were correlated positively with the levels of serum IL-21 and Gd-IgA1 as well as 24 h urinary proteins. Treatment with prednisone significantly reduced the frequency of CD4+CXCR5+ and CD4+CXCR5+PD-1+ TFH cells and the levels of serum IL-21, but increased IL-4 and IL-10 in those patients. A higher frequency of CD4+CXCR5+ TFH cells existed in patients with IgAN and may be associated with the development of IgAN.