891 Eosinophilic Ileitis and Tissue Remodeling in the SAMP1/SkuSlc Mouse Strain

Abstract

BACKGROUND: We have previously shown that esophageal subepithelial fibrosis occurs in 57% of children with eosinophilic esophagitis (EE) regardless of presenting symptoms. Among the children studied, all those with dysphagia and food impactions had esophageal fibrosis. In this study, our aims were to assess whether fibrosis can be quickly reversed with various therapies for EE, and which therapies are more likely to succeed in its reversal. METHODS: Records on all children with EE diagnosed and followed by a single pediatric gastroenterologist (MC) since 2005 were retrieved. EE was diagnosed based on gastroesophageal symptoms refractory to antacid therapy and presence of >15 intraepithelial eosinophils in a maximum high power field (HPF) on esophageal biopsies. Study inclusion criteria were presence of esophageal lamina propria (LP) fibrosis in an esophageal biopsy (proximal and/or distal biopsy) and subsequent esophageal biopsies containing LP following shortterm therapy with either swallowed fluticasone or dietary restriction. Hematoxylin and eosinstained biopsies were retrieved for eosinophil counts, and additional sections were stained with trichrome for evaluation of fibrosis. Fibrosis was defined as densely compacted LP collagen fibers found at any site. Pathologists were blinded for the type of therapy received. Records were reviewed for clinical symptoms. Successful response to therapy for EE was defined as symptom resolution and drop in esophageal eosinophils to <15/HPF. RESULTS: 15 children who received 19 therapies (total 34 endoscopies) were included. Main presenting symptoms included abdominal pain (2), vomiting (5), reflux (3), and dysphagia (5). Mean peak esophageal eosinophil count at diagnosis was 78/HPF. Follow-up with swallowed fluticasone (n=9) and dietary restriction therapies (4 amino acid formula, 6 empiric food elimination) was obtained. All follow-up biopsies were performed 2-3.5 months following therapy initiation. The mean of esophageal LP pieces evaluated per endoscopy was 3.6. Successful response to swallowed fluticasone was 100% (9/9) and to dietary therapy was 50% (5/10: 4/4 amino acid formula, 1/6 empiric food elimination). LP fibrosis resolved in 5/9 successful therapies with swallowed fluticasone regardless of presenting symptoms, and in 1/5 successful dietary therapies. Fibrosis was persistent in all 5 instances of therapy failures. CONCLUSIONS: Esophageal LP fibrosis is persistent with persistent EE. Fibrosis can be reversed with successful therapy for EE in children. Swallowed fluticasone seems to be more effective than limited dietary therapy in reversing fibrosis when short-term effect of therapy is examined.