Fig. 2
Characterization of cell infiltrates in the epithelium and lamina propria of the duodenum. Duodenal biopsies with CD117-expressing cells (a), which include eosinophils expressing eosinophil peroxidase (EPO) and containing specific granules (b); and mast cells (M) expressing tryptase and located in the lamina propria and epithelium (arrows, c). Mast cells in the lamina propria coexpress tryptase and chymase (d). Mast cells in the epithelium (arrows) coexpress tryptase and carboxypeptidase A3 (e)