Prevalence of esophageal eosinophils in patients with Barrett's esophagus.

OBJECTIVES: Recent studies have demonstrated high esophageal eosinophil counts in patients with GERD similar to eosinophilic esophagitis (EoE) yet the frequency of esophageal eosinophilia in GERD is unknown. Our aim was to determine the prevalence of dense esophageal eosinophilia in patients with Barrett's esophagus as a manifestation of GERD. METHODS: The Mayo Clinic pathology database was reviewed for patients diagnosed with Barrett's esophagus from January to December 2008 with squamous mucosa obtained during endoscopic surveillance. Clinical, endoscopic, and histologic findings were reviewed. Patients with ≥15 eosinophils per high powered field were identified and compared to those without esophageal eosinophilia. RESULTS: Two hundred patients with Barrett's esophagus and squamous tissue obtained at the time of biopsy were identified. Fourteen of the 200 patients (7%) had ≥15 eosinophils per high powered field. Demographics, symptoms, and proton pump inhibitor therapies were similar between those with and without esophageal eosinophilia. Endoscopic features suggestive of EoE were found in the squamous mucosa of 2 patients with and 7 patients without esophageal eosinophilia. Use of photodynamic, radiofrequency ablation, or monopolar electrocoagulation therapy for ablation of Barrett's mucosa was not associated with a higher rate of esophageal eosinophilia. Basal cell hyperplasia, papillary elongation, and spongiosis occurred frequently in association with esophageal eosinophilic infiltration. CONCLUSIONS: High esophageal eosinophil counts were found in 7% of this cohort of 200 patients with Barrett's esophagus and likely underestimates prevalence. The finding of esophageal eosinophilia in this cohort was independent of proton pump inhibitor use, features of EoE, or endoscopic therapy for Barrett's esophagus. Further studies are needed to assess if these findings are applicable to all patients with GERD.