Thymic stromal lymphopoietin (TSLP) enhanced IgA production in follicular dendritic cell (FDC)-associated clusters through TSLP receptor (TSLPR), and serum IgA and TSLP concentrations (A) Left to right in the upper row: morphology, CD10 + GC cells and CD21 + FDCs in FDC-associated clusters isolated from tonsillar GCs of IgAN patients. FDC-associated clusters are composed of CD 10 + GC cells and CD21 + FDCs, with about 1 FDC per 10 lymphocytes in each FDC-associated cluster. (B, C) Left to right in the lower row: IgA and TSLP concentrations in the supernatants of FDC-associated clusters. IgA and TSLP were quantified in the supernatants using ELISA. Combined data (mean ± SD) from experiments using FDC-associated clusters from 3 IgAN patients are presented. (D, E) The IgA and TSLP concentrations in the sera of 20 IgAN patients with Tripterygium Wilfordii treatment, 20 IgAN patients without treatment, 20 non-IgAN patients with chronic tonsillitis patients, and 20 healthy volunteers were measured by ELISA. Error bars show means ± SEMs. * , P