Objectives: The esophageal mucosal integrity is impaired in patients with eosinophilic esophagitis (EoE). We aimed to evaluate the effect of fluticasone propionate on inflammation and functional and structural markers of esophageal mucosal barrier integrity in adult patients with EoE.
Methods: In this prospective study, we included 15 EoE patients (median age (IQR), 43 (30-45) years). Patients underwent upper endoscopy before and after an 8-week course of swallowed fluticasone propionate 500 μg BID. Several parameters of esophageal mucosal barrier integrity were evaluated: esophageal electrical tissue impedance in vivo during endoscopy, transepithelial electrical resistance (TER) and transepithelial molecule flux in Ussing chambers using esophageal biopsy specimens, and intercellular spaces as a structural marker of permeability using electron microscopy. Esophageal eosinophils and mast cells were counted, and expression of inflammatory cytokines and barrier integrity proteins was investigated using qPCR. Esophageal symptoms and signs were also assessed.
Results: Peak eosinophil and mast cell counts decreased significantly after fluticasone propionate treatment. The esophageal mucosal integrity increased substantially during treatment, as shown by increased extracellular impedance and TER (both P<0.01) and decreased transepithelial molecule flux in Ussing chambers (P<0.05). Whereas expression of genes encoding for inflammatory cytokines (IL5, IL13, eotaxin-3, periostin, TSLP) decreased after treatment, expression of genes encoding for barrier integrity proteins (filaggrin and desmoglein-1) increased.
Conclusions: Fluticasone propionate treatment decreases eosinophilic inflammation and improves the esophageal mucosal barrier integrity in adult EoE patients. Improvement of the mucosal barrier integrity correlates with normalization of expression of desmoglein-1 and filaggrin marker genes.