392 Baseline Characterization of Patients With Eosinophilic Esophagitis (EoE) Using the EoE Histology Scoring System and Correlations With Endoscopic and Symptom Outcomes: Analyses From a Randomized, Placebo-Controlled Trial

Abstract

INTRODUCTION: It is becoming clear that eosinophilic esophagitis (EoE) activity cannot be measured by eosinophils alone, and that a more complete assessment is needed. The EoE Histology Scoring System (EoE HSS) measures the severity (grade) and extent (stage) of 8 histopathologic features in EoE: eosinophilic inflammation (EI); basal zone hyperplasia (BZH); eosinophilic abscess (EA); eosinophilic surface layering (SL); dilated intercellular spaces (DIS); surface epithelial alteration (SEA); dyskeratotic epithelial cells (DEC); and lamina propria fibrosis (LPF). We aimed to assess EoE histology at baseline using the EoE HSS, and to compare correlations between this and endoscopic and symptom outcomes. METHODS: This study analyzed baseline data from a 12-week, phase 2, randomized, placebo-controlled trial of budesonide oral suspension in patients with EoE (MPI 101-06; NCT01642212). Patients were eligible for inclusion if they were aged 11–40 years and had EoE with dysphagia. Esophageal biopsies from patients were examined, and mean EoE HSS total score ratios and mean individual feature scores were calculated at baseline for all patients (irrespective of treatment allocation). A correlation analysis was then performed to compare these scores with Dysphagia Symptom Questionnaire (DSQ) scores and those from the EoE Endoscopic Reference Score (EREFS) system at baseline. RESULTS: In total, 87 patients were included for analysis. At baseline, mean (standard deviation) EoE HSS grade and stage total score ratios for all patients were 0.5 (0.2) and 0.4 (0.1), respectively. For individual EoE HSS features, a summary of mean grade and stage scores at baseline is shown in Table 1; the most severe features for grade and stage were EI, BZH, DIS and LPF. At baseline, mean EoE HSS grade and stage total score ratios did not correlate with mean DSQ score, but did correlate significantly with mean EREFS score (grade: R = 0.3166; P = 0.0028; stage: R = 0.3344; P = 0.0015; Table 2). Similarly, mean scores for individual EoE HSS features did not correlate with mean DSQ score at baseline, but did correlate with mean EREFS score for 4 and 3 of the 8 features for grade and stage scores, respectively (Table 2). CONCLUSION: The most severe EoE HSS features at baseline for grade and stage were EI, BZH, DIS and LPF. At baseline, there were significant correlations between the EoE HSS and endoscopic severity, but not dysphagia. This suggests that the EoE HSS could become an essential and independent tool to measure EoE activity.