Baseline Gastrointestinal Eosinophilia Is Common in Oral Immunotherapy Subjects With IgE-Mediated Peanut Allergy

Abstract

Rationale: Oral immunotherapy (OIT) is an emerging treatment for food allergy. While desensitization is achieved in most subjects, many experience gastrointestinal symptoms and few develop eosinophilic gastrointestinal disease. It is unclear whether these subjects have subclinical gastrointestinal eosinophilia (GE) at baseline. We aimed to evaluate the presence of GE in subjects with food allergy before peanut OIT.Methods: We performed baseline esophagogastroduodenoscopies on 21 adults before undergoing peanut OIT. Subjects completed a detailed gastrointestinal symptom questionnaire. Endoscopic findings were assessed using the Eosinophilic Esophagitis (EoE) Endoscopic Reference Score (EREFS) and biopsies were obtained from the esophagus, gastric antrum, and duodenum. Esophageal biopsies were evaluated using the EoE Histologic Scoring System. Immunohistochemical staining for eosinophil peroxidase (EPX) was also performed. Hematoxylin and eosin and EPX stains of each biopsy were assessed for eosinophil density and EPX/mm2 was quantified using automated image analysis.Results: All subjects were asymptomatic. Pre-existing esophageal eosinophilia (>5 eosinophils per high-power field [eos/hpf]) was present in five participants (24%), three (14%) of whom had >15 eos/hpf associated with mild endoscopic findings (edema, linear furrowing, or rings; median EREFS = 0, IQR 0–0.25). Some subjects also demonstrated basal cell hyperplasia, dilated intercellular spaces, and lamina propria fibrosis. Increased eosinophils were noted in the gastric antrum (>12 eos/hpf) or duodenum (>26 eos/hpf) in 9 subjects (43%). EPX/mm2 correlated strongly with eosinophil counts (r = 0.71, p < 0.0001).Conclusions: Pre-existing GE is common in adults with IgE-mediated peanut allergy. Eosinophilic inflammation (EI) in these subjects may be accompanied by mild endoscopic and histologic findings. Longitudinal data collection during OIT is ongoing.

Increased Production of LIGHT by T Cells in Eosinophilic Esophagitis Promotes Differentiation of Esophageal Fibroblasts Toward an Inflammatory Phenotype

“…Resulting cocultures were fixed in 1% paraformaldehyde in phosphatebuffered saline for 20 minutes and stained with H&E or eosinophil peroxidase (EPX) (antibody is a kind gift from Dr Elizabeth Jacbosen). 30 To assess the involvement of intercellular adhesion molecule-1 (ICAM-1) on fibroblast-eosinophil adhesion, LIGHT-treated fibroblasts were incubated with 10 mg/mL anti-ICAM-1 antibody or isotype. After 1 hour, eosinophils were added.…”

Eosinophils in Eosinophilic Esophagitis: The Road to Fibrostenosis is Paved With Good Intentions

“…To address this, we performed a study analyzing longitudinal endoscopic biopsies during a 2-year clinical OIT trial in adults with IgE-mediated peanut allergy (23,24). We observed that some subjects did, indeed, have asymptomatic esophageal eosinophilia (≥ 15 eos/hpf) at baseline; eosinophils are not present in the normal esophagus.…”

<p>The Role of Food Allergy in Eosinophilic Esophagitis</p>

“…47 Among adults with peanut allergy, a recent report identified 14% with subclinical esophageal eosinophilia. 48 Connections between FA and EoE can also be seen when examining the natural history and treatment of FA. Maggadottir et al described 17 pediatric EoE cases in which an established food trigger for EoE was the same food that had historically caused immediate FA but had been "successfully" introduced into the diet.…”