Fig. 4From: Distinct phenotypic subpopulations of circulating CD4+CXCR5+ follicular helper T cells in children with active IgA vasculitisCorrelation between different phenotypic subpopulations of Tfh cells and serum IgA, complement C4 or plasma IL-21. The correlation between the indicated Tfh cells and serum IgA (a-d), plasma IL-21 (e-g) and C4 (h) was analyzed by Pearson rank correlation testBack to article page