D1.168 - Are Asymptomatic and Symptomatic Eosinophilic Esophagitis Different Phenotypes in Children?

The prevalence of childhood eosinophilic esophagitis (EoE), characterized by different phenotypes and endotypes, has been increasing in the recent years. Phenotypes associated with severe inflammation and atopic diseases are linked to Th2 inflammation, whereas phenotypes characterized by fibrosis and low inflammation are associated with an increased risk of fibrosis.

Symptomatic and asymptomatic EoE patients are often identified due to the frequent use of endoscopy, leading to discussions regarding the necessity of treatment for asymptomatic patients and the potential for them to evolve into symptomatic disease. We planned our study to compare the clinical, endoscopic, and histological findings of patients diagnosed with symptomatic and asymptomatic EoE and to identify potential biomarkers.

A total of 37 patients diagnosed with EoE at the Ege University Faculty of Medicine Department of Pediatric Allergy between 2009 and 2023 were included in the study, comprising 15 symptomatic patients (Group A) and 22 asymptomatic patients (Group B). Group B patients were further divided into two subgroups: Group A (n=15), who were evaluated prior to oral immunotherapy (OIT), and Group B (n=7), who were evaluated after OIT. Endoscopic findings of all patients were assessed using the Endoscopic Reference Score (EREFS), and histopathological findings were evaluated using the Eosinophilic Esophagitis Histological Scoring System (EoEHSS). I-SEE Clinical Scores were also determined.

Of the total 37 patients included in the study, 29 (78.4%) were male. The mean age was 111.0 months (range: 25.0-233.1 months). Among the 15 symptomatic patients, 6 (40%) reported dysphagia, 5 (33.3%) had abdominal pain, 2 (13.3%) experienced weight loss, and 2 (13.3%) had vomiting complaints. In the symptomatic group, 12 (80.0%) patients had concomitant allergic diseases. No significant differences were found between the groups regarding atopic diseases other than food allergies and aeroallergen sensitivity (p>0.05). Eosinophilia was detected in the upper esophagus of 85.7% (n=6) of Group B patients (p=0.043). Endoscopic findings were similar between symptomatic and asymptomatic patients. In histopathological assessments, basal cell hyperplasia, fibrosis, and total EoEHSS scores were significantly higher in the symptomatic group (p=0.026, p<0.01, p<0.01, respectively). In the I-SEE scoring, inflammatory scores were similar between groups, while fibrotic, clinical, and total scores were higher in symptomatic patients (p=0.001, p<0.01, p=0.001, respectively). Between the asymptomatic groups (A and B), endoscopic and histological scores were comparable; however, in the I-SEE scoring, inflammatory scores were higher in the pre-OIT asymptomatic group compared to the post-OIT group (p=0.014). Other subgroup analyses can be seen in Tables 1, 2, and 3.

The significant presence of fibrotic histological scores in the symptomatic group suggests that food allergy-related asymptomatic patients may represent a distinct EoE phenotype. Furthermore, developing scoring systems for fibrotic histological cutoffs will provide insights that could predict the evolution into fibrotic, scariform disease.