This was a prospective study at the University of North Carolina from 2009-2012. We enrolled consecutive adults from age 18 to 80 years undergoing outpatient esophagogastroduodenoscopy who had either dysphagia or symptoms of gastroesophageal reflux disease. Patients were excluded if they had a known eosinophilic gastrointestinal disorder, including eosinophilic esophagitis, were anticoagulated or having an active GI bleed, had known esophageal varices, esophageal cancer, or prior esophageal surgery, had medical instability precluding enrollment, or were unable to read or understand the consent form. Details of this study design have been previously reported.13 (link)Cases of eosinophilic esophagitis were defined as per consensus guidelines.6 (link),7 (link) Specifically, patients were required to have at least one typical symptom of esophageal dysfunction (dysphagia, food impaction, or heartburn); at least 15 eos/hpf on esophageal biopsy after an 8 week proton pump inhibitor trial (20-40 mg twice daily of any of the available agents, selected at the discretion of the clinician); and other causes of esophageal eosinophilia excluded.6 (link),7 (link) Subjects without eosinophilic esophagitis did not meet these clinical or histologic criteria, but could have other findings or diagnoses. Of note, a non- eosinophilic esophagitis subject could have ≥ 15 eos/hpf attributable to a different cause, such as proton pump inhibitor-responsive esophageal eosinophilia, reflux, achalasia or esophageal dysmotility, infection, etc.7 (link) Samples from the proton pump inhibitor-responsive esophageal eosinophilia patients were analyzed after the proton pump inhibitor trial, and were included in the group of subjects without eosinophilic esophagitis; all of these proton pump inhibitor-responsive esophageal eosinophilia subjects were therefore on proton pump inhibitor. All eosinophilic esophagitis subjects were also on proton pump inhibitor, as per diagnostic guidelines. The other study subjects without eosinophilic esophagitis could be on proton pump inhibitor as clinically indicated at the discretion of their referring provider.
During the endoscopy, a total of five research protocol esophageal biopsies were obtained (two from the proximal, one from the mid, and two from the distal esophagus) to maximize eosinophilic esophagitis diagnostic sensitivity.15 (link) Distal biopsies were obtained 3 cm above the gastroesophageal junction, mid esophageal biopsies were obtained 10 cm above the gastroesophageal junction, and proximal esophageal biopsies were obtained 15 cm above the gastroesophageal junction. Each esophageal biopsy fragment was collected, labelled, processed, and embedded into paraffin separately. Concomitant gastric and duodenal biopsies were used to exclude eosinophilic gastritis or gastroenteritis. At the discretion of the endoscopist, additional clinical biopsies could be taken as needed. The study was approved by the University of North Carolina Institutional Review Board, and subjects provided informed consent prior to endoscopy.
During the endoscopy, a total of five research protocol esophageal biopsies were obtained (two from the proximal, one from the mid, and two from the distal esophagus) to maximize eosinophilic esophagitis diagnostic sensitivity.15 (link) Distal biopsies were obtained 3 cm above the gastroesophageal junction, mid esophageal biopsies were obtained 10 cm above the gastroesophageal junction, and proximal esophageal biopsies were obtained 15 cm above the gastroesophageal junction. Each esophageal biopsy fragment was collected, labelled, processed, and embedded into paraffin separately. Concomitant gastric and duodenal biopsies were used to exclude eosinophilic gastritis or gastroenteritis. At the discretion of the endoscopist, additional clinical biopsies could be taken as needed. The study was approved by the University of North Carolina Institutional Review Board, and subjects provided informed consent prior to endoscopy.
