Presence of intraepithelial food antigen in patients with active eosinophilic oesophagitis

Background Although eosinophilic oesophagitis (EoE) is putatively mediated by an abnormal response to food antigen, the oesophagus is considered relatively impermeable to large molecules. Aim To assess whether food antigens penetrate the oesophageal mucosa in patients with EoE. Methods Anti-gliadin staining was performed in three groups: active EoE, inactive EoE and EoE patients on a low or gluten free diet. To appraise the specificity of our results, we also performed gliadin staining on six patients without oesophageal disease who were consuming gluten. The groups with EoE on gluten also underwent endoscopic infusion with gluten containing soy sauce and repeat biopsies during the endoscopy. We measured eosinophil density, dilated intercellular spaces (on a 0-4+ scale) and gliadin in oesophageal mucosa by immunofluorescence. Results Patients with active EoE had significantly greater epithelial density of anti-gliadin staining when compared to inactive EoE (P<0.0065) and gluten-free patients (P<0.0008) at baseline and after soy infusion. Gliadin was not detected in non-EoE control patients. The distribution of gliadin was both cytoplasmic and nuclear. There was good correlation of dilated intercellular spaces grade and total gliadin staining intensity (r=0.577, P=0.0077). Acute oesophageal perfusion of a commercial gliadin-rich soy sauce did not lead to an increase in gliadin staining in active or inactive EoE. Conclusion These findings suggest, although do not prove, that antigen penetration in active eosinophilic oesophagitis might be facilitated by impairment of epithelial integrity.