Effect of glucocorticoids on GCs. (A) Specific chemoattraction of normal B cells by thymus extracts from adult controls (A ctrl), MG untreated (MG), and MG glucocorticoid-treated patients (MG-t). Each dot represents one sample after subtracting the spontaneous migration. (B) Four thymic extracts from MG patients used in panel A were incubated alone or with addition of anti-CXCL13, anti-CCL21, or mouse control antibody. The results are expressed as the mean and SEM. (C) Immunohistochemical analysis on thymic sections from A ctrl, MG, and MG-t patients (magnification, 5×). In red, epithelial network stained with antikeratin antibody; in green, FDC and B cells stained with anti-CD21 antibody. The whole sections were scanned using a microarray scanner. (D) Quantification of CD21 expression in the thymus of A ctrl, MG, and MG-t patients using Image J software. The P value was obtained by the nonparametric one-way analysis of variance (Kruskal-Wallis test). The horizontal lines in panels A and D represent the median value.