Esophageal mast cells may be associated with the perception of symptoms in patients with eosinophilic esophagitis

Background Eosinophilic esophagitis (EoE) is a type 2 helper T-cell (Th2)-mediated allergic disease that involves mast cells. This study aimed to clarify the relationship between perception of symptoms and mast cell levels in patients with EoE. Methods We enrolled patients with asymptomatic esophageal eosinophilia (aEE) and those with symptomatic EoE. Immunofluorescence staining was performed on esophageal biopsy specimens to quantify mast cell-related molecules, such as tryptase, proteinase-activated receptor (PAR)-2, and vasoactive intestinal peptide receptor (VPAC)-1. Results We evaluated 28 and 58 patients with aEE and EoE, respectively. There were no significant differences in clinical and endoscopic features and peak eosinophil counts between both groups. Mast cell tryptase-positive areas were significantly higher in EoE than in aEE (4.9 [3.5–6.2] vs. 2.0 [1.2–3.4] %, p < 0.01). The number of PAR-2-positive cells was significantly higher in EoE than in aEE (14 [8.8–20.0] vs. 4 [2.8–8.0] cells/high-power field [HPF], p < 0.01). The number of VPAC-1-positive cells was significantly higher in the EoE group than in the aEE group (13 [8.8–16.0] vs. 6 [3.0–9.3] cells/HPF, p < 0.01). A positive correlation was observed between the numbers of PAR-2-positive cells and VPAC-1-positive cells ( r = 0.851, p < 0.01). Moreover, mast cell tryptase-positive areas positively correlated with the number of PAR-2- and VPAC-1-positive cells ( r = 0.352, p < 0.01; r = 0.355, p < 0.01, respectively). Conclusions Esophageal mast cells and their receptors, PAR-2 and VPAC-1, may contribute to the perception of symptoms in patients with EoE.