Esophageal Compliance Quantifies Epithelial Remodeling in Pediatric Patients With Eosinophilic Esophagitis

Pathophysiology and Clinical Impact of Esophageal Remodeling and Fibrosis in Eosinophilic Esophagitis

Most of the major clinical signs and consequences of eosinophilic esophagitis seem to be related to tissue remodeling. Important data on remodeling activity in patients with eosinophilic esophagitis are provided by a range of current and new biologic markers and diagnostics. To completely clarify the possible advantages and restrictions of therapeutic approaches, clinical studies should take into consideration the existence and reversibility of esophageal remodeling. The degree of mucosal or submucosal disease activity may not be reflected by epithelial eosinophilic inflammation, which is used to define one criterion of disease activity".

A Comparison of Functional Luminal Imaging Probe With High-resolution Manometry, Timed Barium Esophagram, and pH Impedance Testing to Evaluate Functional Luminal Imaging Probe's Diagnostic Capabilities

OBJECTIVE

The aims of this study are to determine the functional luminal imaging probe's (FLIP) diagnostic utility by comparing FLIP measurements with results from other esophageal evaluation standards.

BACKGROUND

The FLIP is an esophageal evaluation technique performed at the time of endoscopy. Few studies have evaluated FLIP diagnostic capabilities compared with the established testing techniques, including high-resolution manometry (HRIM), time barium esophagram (TBE), and 24-hour impedance-pH monitoring.

PATIENTS AND METHODS

A retrospective review was performed for 413 preintervention patients who underwent FLIP testing during endoscopy. Data from HRIM, 24-hour pH monitoring, and TBE were compared.

RESULTS

Abnormal Distensibility Index (DI) was associated with abnormal integrated relaxation pressure (IRP; P = 0.003). Average DI was higher in patients with abnormal IRP (>15 mm Hg) when a hiatal hernia was present (P = 0.025). The total agreement between correlated diagnoses from FLIP and HRIM was 33.5%. DI was not associated with acid exposure time on pH monitoring. Agreement between FLIP and TBE was 49% with a sensitivity of 98.1% and a specificity of 36.5%. A 60 mL distension had a significantly lower detection rate than 40 mL and 50 mL for active peristalsis and was unaffected by pressure (P < 0.05).

CONCLUSIONS

FLIP as an adjunct to HRIM is supported by strong metric correlation. FLIP was not correlated to pH monitoring findings, suggesting FLIP is not useful in reflux assessment. The agreement between FLIP and TBE was lower than in previous studies. Hiatal hernia impacted the normality between DI and IRP, not between FLIP and TBE. We suggest analyzing peristaltic patterns on panometry at all fill volumes to optimize detection.

The Slender Esophagus: Unrecognized Esophageal Narrowing in Eosinophilic Esophagitis

INTRODUCTION

Inflammation in eosinophilic esophagitis (EoE) often leads to esophageal strictures. Evaluating esophageal narrowing is clinically challenging. We evaluated esophageal distensibility as related to disease activity, fibrosis, and dysphagia.

METHODS

Adult patients with and without EoE underwent endoscopy and distensibility measurements. Histology, distensibility, and symptoms were analyzed.

RESULTS

Patients with EoE had significantly lower distensibilities than controls. We found a cohort with esophageal diameter under 15 mm despite lack of dysphagia.

DISCUSSION

This study raises concern that current assessments of fibrostenosis are suboptimal. We describe a cohort with unrecognized slender esophagus that were identified through impedance planimetry measurements. This tool provides additional information beyond symptomatic, histologic, and endoscopic assessments.

Measuring esophageal compliance using functional lumen imaging probe to assess remodeling in eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is associated with fibrostenotic remodeling that can be objectively assessed using the functional lumen imaging probe (FLIP). This is typically done using a metric called distensibility plateau (DP). We aimed to describe a novel measure of compliance of the esophageal body and evaluate the associated clinical characteristics in EoE.

METHODS

One hundred seventy-one adult patients with EoE (mean (SD) age 38 (12) years), 31% female and 35 healthy, asymptomatic controls who completed 16-cm functional luminal imaging probe (FLIP) during endoscopy, were evaluated in a cross-sectional study. The esophageal body DP and compliance were measured using a customized analysis program, with compliance calculated as (Δ esophageal body volume)/(Δ pressure) between two FLIP-filled volumes.

RESULTS

In controls, the median (5-95th percentile) DP was 19.8 mm (17.9-21) and esophageal body compliance was 0.37 ml/mmHg (0.18-1.1), which was greater than in EoE (DP 19 (11-21)), compliance 0.19 (0.02-0.71), p-values <0.001. Among EoE patients, 70 (41%) had normal compliance (>0.2 ml/mmHg) and normal DP (>17 mm); 11 (6%) had normal compliance and reduced DP; 34 (20%) had reduced compliance and normal DP; and 56 (33%) had reduced compliance and reduce DP. Patients with both reduced compliance and DP had the greatest proportion of severe rings (61% with EREFS score 2-3) and stricture (100%).

CONCLUSION

FLIP provides an objective evaluation of biomechanical properties of the esophageal wall that appears enhanced by complementary application of metrics of DP and esophageal body compliance.

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.

Functional Luminal Imaging Probe in the Management of Pediatric Esophageal Disorders

BACKGROUND

Functional luminal imaging probe (FLIP) measures pressure-geometry relationships of digestive luminal space. When used in esophageal disorders, it provides several luminal parameters that help better understand the pathophysiology. Data about the potential utility of FLIP in pediatrics are scarce and there is no standardized use in children. We aim to describe the use of FLIP in our center, its safety, feasibility, and clinical impact in esophageal disorders in children.

METHODS

Consecutive FLIP recordings performed at the Centre Hospitalier Universitaire-Sainte-Justine, Montréal, Canada between February 2018 and January 2021 were extracted. A chart review was conducted for demographics and medical history. Symptomatology after the procedure was evaluated with validated dysphagia scores.

KEY RESULTS

Nineteen patients were included (11 girls, median age 16 years, range 3.2-19.6) with achalasia (n = 5), post-Heller's myotomy dysphagia (n = 3), esophagogastric junction outflow obstruction (n = 3), congenital esophageal stenosis (n = 2); post-esophageal atresia repair stricture (n = 3), and post-fundoplication dysphagia (n = 3). There was no significant correlation between integrated relaxation pressure measured with high resolution manometry and distensibility index (DI). The use of FLIP made it possible to differentiate between dysphagia related to an esophageal obstruction (DI < 2.8 mm2/mmHg) and dysphagia without major motility disorder (DI > 2.8 mm2/mmHg) that guided the indication for dilation. FLIP led to a change in management in 47% of the patients. Forty-seven percent of the patients were symptom free at the time of the evaluation.

CONCLUSIONS INFERENCES

FLIP provides key esophageal luminal values and therefore can play an important role in pediatric esophageal disorders management.

Plasminogen Activator Inhibitor-1 as a Marker of Esophageal Functional Changes in Pediatric Eosinophilic Esophagitis

BACKGROUND & AIMS

Esophageal remodeling in eosinophilic esophagitis (EoE) can lead to esophageal rigidity with eventual luminal compromise and stenoses. Gauging esophageal functional alterations in EoE is challenging. An epithelial marker of functional remodeling would impact EoE management.

METHODS

Esophageal biopsy specimens from children with and without EoE and primary human esophageal epithelial cells were used for PAI-1 immunohistochemistry, and cell proliferation experiments. PAI-1 immunostaining and basal cell hyperplasia were assessed in the context of concurrently obtained esophageal compliance measures on endoscopic functional lumen imaging probe (EndoFLIP).

RESULTS

EndoFLIPs were performed in 45 children (32 with and 13 without EoE). Epithelial PAI-1 was increased in patients with active EoE versus inactive or control patients (P < .01). Esophageal compliance was lower in EoE patients versus controls, particularly in the proximal esophagus (P < .001). Proximal compliance was the strongest predictor of EoE (AUROC 0.88, 95% CI 0.77, 0.98) with esophageal compliance of less than 2.6%mL/mmHg demonstrating 82% sensitivity and 84% specificity for EoE. PAI-1 inhibition significantly diminished esophageal epithelial cell proliferation, suggesting PAI-1 could trigger basal cell hyperplasia. A composite mid-esophageal BZH + PAI-1 score was the strongest predictor of altered compliance (P = .02, AUROC 0.89 (95% CI 0.80, 0.99).

CONCLUSIONS

PAI-1 is significantly elevated in pediatric EoE and distinguishes altered compliance in children. PAI-1 may be a novel disease marker and therapeutic target.

Dysmotility in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an immune mediated chronic inflammatory disease resulting from antigen exposure and is characterized by mucosal inflammation with eosinophils. Diagnosis is based on the histological finding of at least 15 eosinophils per high power field in esophageal biopsy specimens from upper gastrointestinal endoscopies. These endoscopies are usually performed in the setting of esophageal dysfunction, however, EoE can occasionally be incidentally diagnosed during endoscopies performed for other indications like coeliac disease. The eosinophilia is in the absence of other causes of esophageal eosinophilia (e.g., parasitic infection, esophageal leiomyomatosis or Crohn's disease). Presentation can be wide ranging and often varies according to age. Infants and younger children can present with choking/gagging, feed refusal, failure to thrive, irritability and vomiting. Older children and adults commonly present with dysphagia, chest pain or food bolus obstruction. EoE was first described in the 1970s, but was only recognized as a distinct disease entity in the 1990s. It has been rising in incidence and prevalence, with reported prevalence ranging between 1 in 2,500 and 1 in 10,000. Although the diagnosis of EoE is dependent on clear histopathologic diagnostic criteria, there is a disconnect between the degree of esophageal eosinophilia and symptom severity especially that of reported dysphagia. Multiple anatomical changes can be seen in the spectrum of presentations of EoE which explain dysphagia, including isolated strictures, diffuse trachealisation, fixed rings, including Schatzki, as well as tissue remodeling and fibrotic changes. However, a majority of EoE patients do not have any of these findings and will still often report ongoing dysphagia. Some will report ongoing dysphagia despite histological remission. This suggests an underlying esophageal dysmotilty which cannot be assessed with endoscopy or correlated with histological changes seen in biopsies. This review will describe the types of motor disturbances seen and their prevalence, the pathophysiological basis of dysmotility seen in EoE, how best to investigate esophageal dysfunction in EoE and the role of manometry in the management of EoE.

Pathophysiology of Dysphagia in Eosinophilic Esophagitis: Causes, Consequences, and Management

Eosinophilic esophagitis (EoE) is a leading cause of food bolus impaction in children and adults. The mechanism of dysphagia in EoE, particularly non-obstructive dysphagia, remains incompletely understood. While fibrostenotic processes appear to be critical in the development of dysphagia, somatosensory dysfunction and dysmotility also contribute. This review considers potential mechanisms of dysphagia and evaluates the utility of current and future treatment strategies in this context.

Dysphagia: Novel and Emerging Diagnostic Modalities

Among recent advances in diagnostics for dysphagia and esophageal motility disorders is the update to the Chicago Classification (version 4.0) for interpretation of high-resolution manometry (HRM) and diagnosis of esophageal motility disorders. The update incorporates application of complementary testing strategies during HRM, such as provocative HRM maneuvers, and recommendation for barium esophagram or functional luminal imaging probe (FLIP) panometry to help clarify inconclusive HRM findings. FLIP panometry also represents an emerging technology for evaluation of esophageal distensibility and motility at the time of endoscopy.

Advances in Endoscopic Procedures in Pediatric Patients

Endoscopy has been a crucial part of the diagnostic and therapeutic modality in pediatric gastrointestinal disorders. This article outlines recent advances in pediatric gastrointestinal endoscopy, including transnasal endoscopy, functional luminal imaging probe, peroral endoscopic myotomy, mucosal impedance, endoscopic vacuum-assisted closure system, chromoendoscopy, artificial intelligence, and machine learning.

Eosinophilic Esophagitis: A Review

Importance

Eosinophilic esophagitis (EoE) is a chronic immune-mediated inflammatory disease of the esophagus that affects an estimated 34.4/100 000 people in Europe and North America. EoE affects both children and adults, and causes dysphagia, food impaction of the esophagus, and esophageal strictures.

Observations

EoE is defined by symptoms of esophageal dysfunction, such as vomiting, dysphagia, or feeding difficulties, in a patient with an esophageal biopsy demonstrating at least 15 eosinophils per high-power field in the absence of other conditions associated with esophageal eosinophilia such as gastroesophageal reflux disease or achalasia. Genetic factors and environmental factors, such as exposure to antibiotics early in life, are associated with EoE. Current therapies include proton pump inhibitors; topical steroid preparations, such as fluticasone and budesonide; dietary therapy with amino acid formula or empirical food elimination; and endoscopic dilation. In a systematic review of observational studies that included 1051 patients with EoE, proton pump inhibitor therapy was associated with a histologic response, defined as less than 15 eosinophils per high-power field on endoscopic biopsy, in 41.7% of patients, while placebo was associated with a 13.3% response rate. In a systematic review of 8 randomized trials of 437 patients with EoE, topical corticosteroid treatment was associated with histologic remission in 64.9% of patients compared with 13.3% for placebo. Patients with esophageal narrowing may require dilation. Objective assessment of therapeutic response typically requires endoscopy with biopsy.

Conclusions and Relevance

EoE has a prevalence of approximately 34.4/100 000 worldwide. Treatments consist of proton pump inhibitors, topical steroids, elemental diet, and empirical food elimination, with esophageal dilation reserved for patients with symptomatic esophageal narrowing.

A unique esophageal extracellular matrix proteome alters normal fibroblast function in severe eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic TH2 disorder complicated by tissue fibrosis and loss of esophageal luminal patency. The fibrostenotic esophagus does not respond well to therapy, but profibrotic therapeutic targets are largely unclear.

OBJECTIVE

Our aim was to utilize proteomics and primary cells as a novel approach to determine relevant profibrotic factors.

METHODS

We utilized primary esophageal EoE and normal fibroblasts, their derivative extracellular matrixes (ECMs), an approach of fibroblast culture on autologous versus nonautologous ECM, and proteomics to elucidate EoE ECM proteins that dysregulate cellular function.

RESULTS

We cultured esophageal fibroblasts from normal esophagi and esophagi from patients with severe EoE on autologous versus nonautologous ECM. The EoE ECM proteome shifted normal esophageal fibroblast protein expression. Proteomic analysis demonstrated that thrombospondin-1 is detected only in the EoE ECM, is central in the EoE ECM protein-protein interactome, is found at significantly elevated levels in biopsy specimens from patients with active EoE, and induces fibroblast collagen I production.

CONCLUSION

Fibroblasts from patients with EoE secrete a unique ECM proteome that reflects their in vivo state and induces collagen I and α-smooth muscle actin protein expression from normal fibroblasts. Thrombospondin-1 is a previously unappreciated profibrotic molecule in EoE.

Sex Differences in Blood Transcriptional Profiles and Clinical Phenotypes in Pediatric Patients with Eosinophilic Esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is an increasingly recognized, chronic inflammatory disease. Recent reports suggest clinical differences between males and females.

OBJECTIVE

To define the relevant molecular pathways that could be related to clinical phenotypes in children with EoE.

METHODS

We performed blood RNA expression analysis in children with newly diagnosed EoE and matched, healthy controls, and applied bioinformatics tools to define EoE host immune biosignatures. Questionnaires and medical records were used to characterize symptoms, esophagogastroduodenoscopy results, and treatment response.

RESULTS

Forty-one subjects (aged 2-17 years) were enrolled; the cohort consisted of 27 males and 14 females. Patients were randomly divided into a discovery cohort (21 EoE patients and 12 controls) that identified 544 significant differentially expressed transcripts (P ≤ .01; 1.25-fold change). Those 544 transcripts correctly classified most EoE patients in the validation cohort (n = 20) from healthy controls. Global transcriptional perturbation relative to healthy controls, Molecular Distance to Health scores were greater in EoE patients than controls (P = .003). When we analyzed subjects based on age and sex, males 13 years of age and older were more likely to have food impactions (P = .033) and to have higher endoscopic severity scores (P = .036). Separate group comparisons according to sex identified 294 differentially expressed transcripts in males and 643 transcripts in female EoE patients. Of those, 37 genes were shared and similarly expressed irrespective of sex.

CONCLUSIONS

Whole blood transcriptional analysis represents a promising noninvasive tool to assess activity of the immune/inflammatory response in children with EoE. Male and female EoE patients showed robust differences in gene expression suggesting distinct pathogenic endotypes.

Diagnosis and treatment of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an eosinophil-rich, TH2 antigen-mediated disease of increasing pediatric and adult worldwide prevalence. Diagnosis requires greater than or equal to 15 eosinophils per high-power field on light microscopy. Symptoms reflect esophageal dysfunction, and typical endoscopic features include linear furrows, white plaques, and concentric rings. Progressive disease leads to pathologic tissue remodeling, with ensuing esophageal rigidity and loss of luminal diameter caused by strictures. Therapies include proton pump inhibitors, elimination diets, and topical corticosteroids. Effective treatment can reverse tissue fibrosis in some patients, as well as decrease the rate of food impactions. Esophageal dilation might be required to increase luminal patency. The chronic nature of EoE necessitates long-term therapy to avoid disease recurrence and complications. This review serves the function of providing the current state-of-the-art diagnostic criteria and disease management for adult and pediatric EoE.

EoE disease monitoring: Where we are and where we are going

OBJECTIVE

To review literature on various methods of monitoring and characterizing eosinophilic esophagitis (EoE) with respect to their validity as well as risk to the patient.

DATA SOURCES

A literature search was performed using PubMed with keyword combinations of EoE and monitoring as well as various techniques used for monitoring, including but not limited to, symptoms, endoscopy, histology, fluoroscopy, FLIP, noninvasive monitoring, and biomarkers.

STUDY SELECTIONS

Case-control studies, observational studies, peer-reviewed reviews and guidelines, and systematic reviews were selected, reviewed, and summarized here.

RESULTS

A wealth of research regarding monitoring of EoE is currently being undertaken and published. Our review highlights those that have been validated and are currently being used, as well as some that show promise for future monitoring and disease characterization.

CONCLUSION

Eosinophilic esophagitis is a chronic condition that at this time requires upper endoscopy as the gold standard of diagnosis and monitoring. There is a great need in the field for less invasive monitoring tools and better ways to characterize disease to allow for personalization of therapies.