# Prevalence of Sensitization to Panallergens and IgG4 Profiles Against Specific Foods in Patients with Allergic-Phenotype Eosinophilic Esophagitis

## TL;DR

This study found that patients with allergic-phenotype eosinophilic esophagitis have distinct IgG4 profiles against specific foods compared to allergic patients and healthy controls.

## Contribution

The study identifies unique IgG4 responses to specific foods in a subset of EoE patients, suggesting a potential diagnostic or therapeutic marker.

## Key findings

- Statistically significant differences in food-specific IgG4 levels were observed for milk, egg, wheat, nuts, soy, cod, and Pru p3/LTP.
- No significant differences were found in sensitization to aeroallergens, foods, or panallergens.
- EDN levels did not differ between the study groups.

## Abstract

Background: The pathophysiological mechanism of eosinophilic esophagitis (EoE) is complex and is still being investigated. We believe that there is a group of patients with eosinophilic esophagitis which could be differentiated as having an allergic phenotype who exhibit a sensitization profile (aeroallergens, panallergens, foods and specific IgG4 levels) with significant differences compared to patients with conventional allergic disease without associated eosinophilic esophagitis and healthy controls. Method: We measured the prevalence of sensitization to aeroallergens, foods and panallergens by means of molecular diagnostic techniques (ImmunoCAPTM ISAC) and determined the levels of specific IgG4 against foods and eosinophilic-derived neurotoxin (EDN) (ImmunoCAP technology) in patients with EoE of an allergic phenotype to study whether there are statistically significant differences with respect to the control groups (patients with different allergic pathologies without EoE and healthy patients without documented allergies). The total number of patients under study was 118, distributed among the different study groups. The case group (Allergic phenotype EoE patients) had 48 subjects. The food and respiratory allergy control groups had 30 subjects each. Finally, we included 10 in the healthy control group. Results: We were able to identify statistically significant differences when comparing levels of food-specific IgG4. Milk, egg, wheat, nuts, soy, cod, and Pru p3/LTP stood out. We did not observe significant differences in relation to sensitization to aeroallergens, foods, or panallergens. We also did not observe differences in EDN levels. Conclusions: We present a study in which statistically significant differences in IgG4 levels were observed in response to different types of food, comparing patients with eosinophilic esophagitis of allergic phenotype (case group) against subjects with allergic pathology without EoE and healthy subjects (control groups). Determining whether the detected foods are clinically relevant or not in these patients would be fundamental to establishing their usefulness as a treatment alternative in our patients.