Defining the Patchy Landscape of Esophageal Eosinophilia in Children With Eosinophilic Esophagitis

Eosinophilic esophagitis: Current concepts in diagnosis and management

ABSTRACT

Eosinophilic esophagitis is an antigen-mediated chronic inflammatory disorder that has risen in incidence and prevalence over the past 2 decades. The clinical presentation is variable and consists of mainly esophageal symptoms such as dysphagia, heartburn, food impaction, and vomiting. Current management relies on dietary elimination, proton-pump inhibitors, and topical corticosteroids with different response rates and relapses after treatment discontinuation. With a better understanding of the underlying pathophysiology, many molecules emerged recently as targeted treatment including dupilumab (IL4/IL13 blocker), as the first FDA-approved biological treatment, which has changed the management paradigm.

Addressing diagnostic dilemmas in eosinophilic esophagitis using esophageal epithelial eosinophil-derived neurotoxin

OBJECTIVES

Eosinophil-derived neurotoxin (EDN) is a viable marker of eosinophilic esophagitis (EoE) disease activity. We studied the utility of measuring EDN from esophageal epithelial brushings for diagnosing EoE, focusing on two scenarios: (1) cases of exclusive distal eosinophilia and (2) cases of discrepancy between endoscopy and histology.

METHODS

Records of patients who underwent esophagogastroduodenoscopy (EGD) with EDN measured via esophageal brushings at Arnold Palmer Hospital for Children in Orlando, Florida from January 2014 to October 2018 were retrospectively reviewed. Demographics, clinical, endoscopic, and histologic data were collected.

RESULTS

We reviewed 231 patient records (66.7% male, mean age 10.3 years, range 1-22 years). EDN values correlated with endoscopic reference score (EREFS) and peak eosinophil count (PEC) (Spearman's rho = 0.756 (p < 0.001) and 0.824 (p < 0.001) respectively). Average PEC, EREFS, and EDN concentrations were higher in patients with active EoE than in controls or patients with EoE in remission (inactive). When grouping patients based on esophageal eosinophilia distribution, EDN mirrored PEC, and EREFS. Patients with exclusive distal eosinophilia had lower EDN concentrations than those with eosinophilia in >1 level of the esophagus (23.8 ± 46.1 mcg/mL vs. 171.3 ± 205.8 mcg/mL respectively, p < 0.001). EDN values were more consistent with EREFS in cases of discrepancies between endoscopic findings and pathology (p < 0.001).

CONCLUSION

EDN measured in esophageal brushing samples reflects disease activity objectively and accurately. It also offers significant value in cases of exclusive distal esophageal eosinophilia and when discrepancies exist between endoscopy and histology.

Esophageal Epithelium and Lamina Propria Are Unevenly Involved in Eosinophilic Esophagitis

BACKGROUND & AIMS

The nature of the involvement of esophageal tissue in eosinophilic esophagitis (EoE) is unclear. We estimated the intrabiopsy site agreements of the EoE Histologic Scoring System (EoEHSS) scores for the grade (degree) and stage (extent) of involvement of the esophageal epithelial and lamina propria and examined if the EoE activity status influenced the intrabiopsy site agreement.

METHODS

Demographic, clinical, and EoEHSS scores collected as part of the prospective Outcome Measures for Eosinophilic Gastrointestinal Diseases Across Ages study were analyzed. A weighted Cohen's kappa agreement coefficient (k) was used to calculate the pairwise agreements for proximal:distal, proximal:middle, and middle:distal esophageal biopsy sites, separately for grade and stage scores, for each of the 8 components of EoEHSS. A k > 0.75 was considered uniform involvement. Inactive EoE was defined as fewer than 15 eosinophils per high-powered field.

RESULTS

EoEHSS scores from 1263 esophageal biopsy specimens were analyzed. The k for the stage of involvement of the dilated intercellular spaces across all 3 sites in inactive EoE was consistently greater than 0.75 (range, 0.87-0.99). The k for lamina propria fibrosis was greater than 0.75 across some of the biopsy sites but not across all 3. Otherwise, the k for all other features, for both grade and stage, irrespective of the disease activity status, was 0.75 or less (range, 0.00-0.74).

CONCLUSIONS

Except for the extent of involvement of dilated intercellular spaces in inactive EoE, the remaining epithelial features and lamina propria are involved unevenly across biopsy sites in EoE, irrespective of the disease activity status. This study enhances our understanding of the effects of EoE on esophageal tissue pathology.

Endoscopy in Pediatric Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic allergen-mediated clinicopathologic condition that currently requires esophagogastroduodenoscopy with biopsies and histologic evaluation to diagnose and monitor its progress. This state-of-the art review outlines the pathophysiology of EoE, reviews the application of endoscopy as a diagnostic and therapeutic tool, and discusses potential complications related to therapeutic endoscopic interventions. It also introduces recent innovations that can enhance the endoscopist's ability to diagnose and monitor EoE with minimally invasive procedures and perform therapeutic maneuvers more safely and effectively.

Esophageal Distensibility Defines Fibrostenotic Severity in Pediatric Eosinophilic Esophagitis

BACKGROUND & AIMS

Identification of fibrosis in pediatric eosinophilic esophagitis (EoE) relies on symptom assessment and endoscopy. Symptoms are highly variable, and early fibrotic remodeling may go undetected on endoscopy yet contribute to esophageal dysfunction. We aimed to assess whether esophageal distensibility has utility in defining fibrostenotic severity in a cohort of pediatric patients with EoE with symptoms of esophageal dysfunction.

METHODS

We analyzed a prospectively recruited a cohort of children ages 9 to 21 years undergoing upper endoscopy and Endoscopic Functional Lumen Imaging Probe (EndoFLIP) for suspected or previously diagnosed EoE. Esophageal distensibility was evaluated by the distensibility index (DI) and esophageal diameter at the distensibility plateau. The association of esophageal distensibility to clinical, endoscopic, and histologic parameters of disease severity was assessed. Receiver operating characteristic analysis was performed to determine the utility of distensibility in defining esophageal rigidity in pediatric EoE.

RESULTS

We identified 59 pediatric patients with EoE undergoing endoscopy and EndoFLIP at a single pediatric tertiary referral center. DI (mm²/mmHg) was significantly lower in patients with fibrotic as compared with inflammatory features on endoscopy (median, 3.3; interquartile range, 2.3-4.4) vs median, 5.5; interquartile range, 4.1-6.0; P = .02) and showed no correlation with eosinophil count. DI <4.5 mm²/mmHg predicted grade 2 rings on endoscopy with area under the curve of 0.81 (P = .0004). DI predicted food impaction in both unadjusted and adjusted models (fully adjusted odds ratio, 1.44; 95% confidence interval, 1.02-2.14; P = .0486).

CONCLUSION

Esophageal distensibility determined by EndoFLIP is a measure of fibrostenotic severity that can be used to clinically phenotype pediatric EoE. We propose parameters of DI <4.5 mm²/mmHg for defining esophageal rigidity in pediatric patients with EoE ages 9 years and older.