Figure 4.

Mast cell quantification in bronchial biopsies. The number of subepithelial tryptase⁺ (M_T), tryptase⁺chymase⁺ (M_TC) and the total number of mast cells (M_T + M_TC) were quantified by immunofluorescence (a, b) and the number of intra‐epithelial tryptase⁺ mast cells were quantified by immunohistochemistry (c). Representative images of immunofluorescence where green and orange arrows indicate M_T and M_TC cells respectively (d) and immunohistochemistry where white arrows indicate tryptase‐positive mast cells (e). Comparisons were made between eosinophil^low vs eosinophil^high patients (a) n = 10 vs n = 13; (c) n = 14 vs n = 15; ICS users vs non‐users (b) n = 16 vs n = 7. P‐values in b signify differences between the same mast cell populations in ICS Yes vs ICS No groups.