A higher frequency of CD4⁺CXCR5⁺ T follicular helper cells in adult patients with minimal change disease.

BACKGROUND: T follicular helper (TFH) cells are involved in the humoral immune responses. This study is aimed at examining the frequencies of different subsets of CD4(+)CXCR5(+) TFH cells in adult patients with minimal change disease (MCD). METHODS: A total of 27 patients and 14 healthy controls (HC) were characterized for the levels of sera cytokines, inducible T-cell costimulator (ICOS), and programmed death 1 (PD-1) of positive TFH cells by flow cytometry. The level of sera IL-21 was examined; 24 h urinary protein and eGFR were calculated. The potential correlation between the frequency of different subsets of TFH cells and the values of clinical measures in MCD patients were analyzed. RESULTS: The frequency of circulating CD4(+)CXCR5(+), CD4(+)CXCR5(+)ICOS(+), and CD4(+)CXCR5(+)PD-1(+) TFH cells and the levels of sera IL-17A, IFN-γ, IL-2, IL-10, IL-4, and IL-21 were significantly higher in MCD patients (P < 0.05) than that in the HC group. Furthermore, the percentages of circulating CD4(+)CXCR5(+) TFH cells were negatively correlated with the values of eGFR (r = -0.4849, P < 0.05) and the percentages of CD4(+)CXCR5(+)PD-1(+) TFH cells were correlated positively with the levels of serum IL-21 (r = 0.6137, P < 0.05) and 24 h urinary protein (r = 0.1410, P < 0.05) in those patients. Also, the percentages of CD4(+)CXCR5(+)ICOS(+) TFH cells were correlated positively with the levels of serum IL-21 (r = 0.6201, P < 0.05) and 24 h urinary protein (r = 0.7519, P < 0.05). Following standard therapies, the percentages of circulating CD4(+)CXCR5(+), CD4(+)CXCR5(+)PD-1(+), and CD4(+)CXCR5(+)ICOS(+) TFH cells and the levels of serum IL-21 were significantly reduced, but the levels of serum IL-4 and IL-10 were increased (P < 0.05). CONCLUSIONS: A higher frequency of CD4(+)CXCR5(+) TFH cells that existed in adult patients with MCD could be new target for intervention of MCD.