Figure 1

ELSs in nasal tissues do not differ between GPA and CRS. (A through D) Immunohistochemistry of GPA displaying CD3⁺ T lymphocytes (A, brown) surrounding a primary CD20⁺ B-cell follicle (B, brown color) with a CD21⁺ FDC network (C, brown), which could be located in proximity to PNAd⁺ high endothelial venules (D, brown). (E through H) Immunohistochemistry of CRS showing CD3⁺ T lymphocytes (E, brown) surrounding a primary CD20⁺ B-cell follicle (F, brown) with a CD21⁺ FDC network (G, brown) that could be located near PNAd⁺ high endothelial venules (H, brown). Nuclei are stained in blue with hematoxylin (Figure 1A-H, Figure 2A-G, K, L).