Eosinophilic esophagitis (EoE) is a chronic, food antigen-mediated disease characterized by esophageal dysfunction and intraepithelial eosinophil accumulation.
We hypothesized that very early onset EoE (V-EoE) would be enriched for early-life and genetic factors and have worse presentation and prognosis than later-onset pediatric EoE (L-EoE).
We conducted a single-site, retrospective review comparing patients diagnosed at age 12 months or less (V-EoE, n = 57) and age 14 to 18 years (L-EoE, n = 70). These patients underwent medical record, EoE Histology Scoring System, Endoscopic Reference Score, and EoE Diagnostic Panel assessment when sample availability permitted. Genetic association used 2 EoE genotype repositories. Data were analyzed using chi-square tests, t tests, Wilcoxon rank-sum tests, Spearman correlations, cluster analysis, and logistic regression.
Among pediatric patients with EoE, diagnosis most commonly occurred within early life (0-24 months, 17%). V-EoE was more likely to attain histologic remission via dietary restriction (P < .0001). Basal zone hyperplasia and eosinophil inflammation were greater in V-EoE (P < .05). Esophageal strictures more commonly occurred in L-EoE (P = .03). V-EoE had lower endoscopic scores (P < .05). Molecular expression was very similar between groups. Cesarean delivery was more common in patients with V-EoE (P = .03). Patients with V-EoE demonstrated enrichment of CAPN14 common genetic variants.
Early-life diagnosis of EoE is a common occurrence. V-EoE responds to standard therapy without early evidence for complications, suggesting a less severe prognosis than hypothesized. Molecular pathogenesis is preserved between V-EoE and L-EoE. Cesarean delivery and CAPN14 genetic variation likely promote earlier disease development.

Eosinophilic esophagitis (EoE) is a chronic, food-driven allergic disease resulting in eosinophilic esophageal inflammation. We recently found that EoE susceptibility is associated with genetic variants in the promoter of CAPN14, a gene with reported esophagus-specific expression. CAPN14 is dynamically up-regulated as a function of EoE disease activity and after exposure of epithelial cells to interleukin-13 (IL-13). Herein, we aimed to explore molecular modulation of CAPN14 expression. We identified three putative binding sites for the IL-13-activated transcription factor STAT6 in the promoter and first intron of CAPN14 Luciferase reporter assays revealed that the two most distal STAT6 elements were required for the ∼10-fold increase in promoter activity subsequent to stimulation with IL-13 or IL-4, and also for the genotype-dependent reduction in IL-13-induced promoter activity. One of the STAT6 elements in the promoter was necessary for IL-13-mediated induction of CAPN14 promoter activity while the other STAT6 promoter element was necessary for full induction. Chromatin immunoprecipitation in IL-13 stimulated esophageal epithelial cells was used to further support STAT6 binding to the promoter of CAPN14 at these STAT6 binding sites. The highest CAPN14 and calpain-14 expression occurred with IL-13 or IL-4 stimulation of esophageal epithelial cells under culture conditions that allow the cells to differentiate into a stratified epithelium. This work corroborates a candidate molecular mechanism for EoE disease etiology in which the risk variant at 2p23 dampens CAPN14 expression in differentiated esophageal epithelial cells following IL-13/STAT6 induction of CAPN14 promoter activity.