Gonsalves, Nirmala

INTRODUCTION: Eosinophilic gastrointestinal diseases (EGIDs) are a set of inflammatory diseases subclassified according to the site(s) of abnormal accumulation of eosinophils (eos) in the gastrointestinal (GI) tract such as eosinophilic esophagitis (EoE), gastroenteritis (EGE), and colitis. These conditions often decrease quality of life due to debilitating symptoms. While the pathogenesis of EGIDs is primarily thought to be driven by eos, there is increasing evidence for the involvement of mast cells (MCs). AIM: To characterize symptomatic patients (pts) with suspected EG/EGE who did not meet histopathologic entry criteria for mucosal eosinophilia for a Phase 2 randomized, double-blind, placebo-controlled study of AK002, an anti-Siglec-8 antibody. METHODS: To undergo screening endoscopy for this study, pts were required to report an average symptom score ≥3 (0 to 10 scale) for abdominal pain, nausea, and/or diarrhea on a daily patient-reported outcome questionnaire for ≥2 weeks and have no other known cause for GI symptoms. During the screening endoscopy, biopsies were systematically obtained from the stomach and duodenum, and read by a single pathologist. Eos counts (eos/hpf; hpf area = 0.237 mm 2 ) were assessed on H&E slides. To quantify MCs, immunohistochemistry for tryptase was performed. We quantified eos and MCs in the stomach and duodenum. Histopathologic entry criteria for the randomized study was ≥30 eos/hpf in 5 hpfs in the stomach (EG) and/or ≥30 eos/hpf in 3 hpfs in the duodenum (EGE). A literature review was conducted to determine normal MC counts in the GI tract. RESULTS: Eighty-eight pts underwent screening endoscopy based upon suspected EG/EGE and active symptoms, and 72 pts met histopathologic eos criteria. All pts whose eos did not meet entry criteria (n = 16) were found to have elevated MC counts (Figure 1; reported normal range = 12-19 MCs/hpf). In these pts, the mean gastric eos count was 6 eos/hpf in 5 hpfs and mean duodenal eos count was 15 eos/hpf in 3 hpfs. In contrast, these pts exhibited a mean gastric MC count of 47 MC/hpf in 5 hpfs and a mean duodenal MC count of 49 MC/hpf in 3 hpfs. Almost all symptomatic pts screened (87/88; 99%) had elevated MC counts. CONCLUSION: Data from this large randomized EG/EGE study showed that symptomatic pts with suspected EG/EGE had increased mucosal MCs with or without mucosal eosinophilia. These data suggest that MCs may play a role in pts with suspected EG/EGE and raise the possibility of a unique clinical presentation driven by MCs.

OBJECTIVES: Eosinophilic esophagitis (EoE), a chronic food allergic disease, lacks sensitive and specific peripheral biomarkers. We hypothesized that levels of EoE-related biomarkers captured using a 1-hour minimally invasive Esophageal String Test (EST) would correlate with mucosal eosinophil counts and tissue concentrations of these same biomarkers. We aimed to determine whether a 1-hour EST accurately distinguishes active from inactive EoE or a normal esophagus. METHODS: In a prospective, multisite study, children and adults (ages 7–55 years) undergoing a clinically indicated esophagogastroduodenoscopy performed an EST with an esophageal dwell time of 1 hour. Subjects were divided into 3 groups: active EoE, inactive EoE, and normal esophageal mucosa. Eosinophil-associated protein levels were compared between EST effluents and esophageal biopsy extracts. Statistical modeling was performed to select biomarkers that best correlated with and predicted eosinophilic inflammation. RESULTS: One hundred thirty-four subjects (74 children, 60 adults) with active EoE (n = 62), inactive EoE (n = 37), and patient controls with a normal esophagus (n = 35) completed the study. EST-captured eosinophil-associated biomarkers correlated significantly with peak eosinophils/high-power field, endoscopic visual scoring, and the same proteins extracted from mucosal biopsies. Statistical modeling, using combined eotaxin-3 and major basic protein-1 concentrations, led to the development of EoE scores that distinguished subjects with active EoE from inactive EoE or normal esophagi. Eighty-seven percent of children, 95% of parents, and 92% of adults preferred the EST over endoscopy if it provided similar information. DISCUSSION: The 1-hour EST accurately distinguishes active from inactive EoE in children and adults and may facilitate monitoring of disease activity in a safe and minimally invasive fashion.

Objective Abnormalities are commonly identified during endoscopy in eosinophilic oesophagitis (EoE). There is no standardised classification to describe these features. This study aimed to evaluate the interobserver agreement of a grading system for the oesophageal features of EoE. Method The proposed system incorporated the grading of four major oesophageal features (rings, furrows, exudates, oedema) and the presence of additional features of narrow calibre oesophagus, feline oesophagus, stricture and crepe paper oesophagus. Endoscopic videos from 25 patients with EoE and controls were reviewed by 21 gastroenterologists. Interobserver agreement was assessed by estimating multi-rater κ and the proportion of pairwise agreement. Results Using the original grading system, agreement for rings, furrows and exudates was moderate (κ=0.38–0.46, 56–65% agreement) but poor for oedema (κ=0.23, 51% agreement). Identification of narrow calibre oesophagus had fair agreement (κ=0.30, 74% agreement) while feline oesophagus had poor agreement (κ=0.15, 68% agreement). After collapsing the severity grading for oedema and furrows and eliminating poorly performing features of feline oesophagus and narrow calibre oesophagus, a modified grading system demonstrated good agreement for the four major features of EoE (κ=0.40–0.54, 71–81% agreement) and additional features of stricture and crepe paper oesophagus (κ=0.52 and 0.58, 79% and 92% agreement). Conclusions The proposed system for endoscopically-identified oesophageal features of EoE defines common nomenclature and severity scores for the assessment of EoE disease activity. The system has good interobserver agreement among practising and academic gastroenterologists.