Histological Response to Fluticasone Propionate in Patients With Eosinophilic Esophagitis Is Associated With Improved Functional Esophageal Mucosal Integrity

Diagnosis and management of eosinophilic esophagitis in children: An update from the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN)

INTRODUCTION

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus characterized by symptoms of esophageal dysfunction and histologically by predominantly eosinophilic infiltration of the squamous epithelium. European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) published a guideline in 2014; however, the rapid evolution of knowledge about pathophysiology, diagnostic criteria, and therapeutic options have made an update necessary.

METHODS

A consensus group of pediatric gastroenterologists from the ESPGHAN Working Group on Eosinophilic Gastrointestinal Diseases (ESPGHAN EGID WG) reviewed the recent literature and proposed statements and recommendations on 28 relevant questions about EoE. A comprehensive electronic literature search was performed in MEDLINE, EMBASE, and Cochrane databases from 2014 to 2022. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess the quality of evidence and formulate recommendations.

RESULTS

A total of 52 statements based on the available evidence and 44 consensus-based recommendations are available. A revision of the diagnostic protocol, options for initial drug treatment, and the new concept of simplified empiric elimination diets are now available. Biologics are becoming a part of the potential armamentarium for refractory EoE, and systemic steroids may be considered as the initial treatment for esophageal strictures before esophageal dilation. The importance and assessment of quality of life and a planned transition to adult medical care are new areas addressed in this guideline.

CONCLUSION

Research in recent years has led to a better understanding of childhood EoE. This guideline incorporates the new findings and provides a practical guide for clinicians treating children diagnosed with EoE.

Pharmacologic Management of Eosinophilic Esophagitis

Proton pump inhibitors (PPIs), swallowed topical corticosteroids (STSs), and dupilumab are highly effective therapies for the treatment of eosinophilic esophagitis. Shared decision-making informs the choice of therapy and factors such as ease of use, safety, cost, and efficacy should be addressed. PPIs are the most common medication utilized early in the disease course; however, for nonresponders, STSs are an excellent alternative. Dupilumab is unlikely to replace PPIs or STSs as first-line therapy, except in highly specific circumstances. Identification of novel biologic pathways and the development of small molecules may lead to a wider range of treatment options in the future.

Barrier Dysfunction in Eosinophilic Esophagitis

PURPOSE OF REVIEW

Compelling evidence over the past decade supports the central role of epithelial barrier dysfunction in the pathophysiology of eosinophilic esophagitis (EoE). The purpose of this review is to summarize the genetic, environmental, and immunologic factors driving epithelial barrier dysfunction, and how this impaired barrier can further promote the inflammatory response in EoE.

RECENT FINDINGS

Common environmental exposures, such as detergents, may have a direct impact on the esophageal epithelial barrier. In addition, the effects of IL-13 on barrier dysfunction may be reduced by 17β-estradiol, Vitamin D, and the short chain fatty acids butyrate and propionate, suggesting novel therapeutic targets. There are many genetic, environmental, and immunologic factors that contribute to epithelial barrier dysfunction in EoE. This leads to further skewing of the immune response to a "Th2" phenotype, alterations in the esophageal microbiome, and penetration of relevant antigens into the esophageal mucosa, which are central to the pathophysiology of EoE.

A meta-analysis on randomized controlled trials of treating eosinophilic esophagitis with budesonide

OBJECTIVE

Eosinophilic esophagitis (EoE) is a chronic, local immune-mediated inflammatory oesophageal disease. Although Budesonide is recommended as one of the first-line drugs for EoE treatment, its efficacy is still controversial in multiple studies. Due to the continuous emergence of new and reliable research evidence in recent years, we updated the meta-analysis using RCT trial results to evaluate the efficacy and safety of budesonide.

MATERIALS AND METHOD

Retrieve the data of the randomised controlled trial literature from 2000 to June 20, 2021, on using Budesonide in the treatment of eosinophilic esophagitis from the three major databases. Based on the results achieved with the Cochrane risk assessment tool, evaluate the quality of the included literature to extract the data, and perform the Meta-analysis with RevMan5.4 and Stata15.0.

RESULTS

A total of 958 articles were retrieved, with 10 articles finally included, thus forming a sample size of 712 cases. The main outcome indicators of the meta-analysis are as follows: (1) Histological remission: the Budesonide group performs better than the placebo control group when it comes to histological remission of injuries [RR = 23.82, 95%CI = (13.46, 42.21), p < .001]; (2) Eosinophil count: the Budesonide group is superior to the control group in terms of reduced eosinophil count [SMD = -1.34, 95%CI = (-1.52, -1.15), p < .001].

CONCLUSION

More and more high-quality randomised controlled trials show that oral budesonide in the treatment of eosinophils esophagitis was better than the placebo group. Mounting high-quality RCTs have confirmed the efficacy of oral budesonide in the treatment of eosinophilic esophagitis and that the effects of this drug may not be so dose-dependent. It is safe to take budesonide for a long time, and this drug is a relatively ideal option for drug treatment of eosinophilic esophagitis at present, so it is worthy of clinical application.Key MessagesWe used high-quality randomised controlled trials to meta-update the previous results to further confirm the clinical efficacy and safety of budesonide.Oral budesonide in the treatment of eosinophilic esophagitis is significantly better than the placebo control group. We have confirmed the value of its clinical application and promotion by including more high-quality randomised controlled trials.We also found that the efficacy of budesonide in patients is not dose-dependent, and more research is needed to confirm this.

Gene expression and clinical outcomes after dietary treatment for eosinophilic esophagitis: a prospective study

BACKGROUND

Eosinophilic esophagitis (EoE) is an allergen-mediated disease and elimination diets have proven to be effective to obtain clinical and histological remission. However, the effect of elimination diets on specific EoE transcripts and their clinical correlates is relatively unknown. The main aim of the study was to evaluate the effect of dietary treatment (four-food elimination diet [FFED]) with or without addition of amino acid-based formula (AAF) on a variety of pro-/anti-inflammatory, epithelial/barrier function and remodeling/fibrosis-related markers of disease activity and clinical correlates (eosinophils, symptoms, and endoscopic signs) in adult EoE patients.

METHODS

We conducted an analysis of biopsy samples and data collected during a randomized controlled trial with an elimination diet in adult patients with active EoE (≥15 eosinophils [eos] per high-power field [hpf]). Demographics, symptoms (SDI-score), endoscopic signs (EREFS) and peak eosinophil counts/hpf were recorded at baseline and after 6 weeks of treatment. Transcripts of 10 indicated genes were measured (qPCR) and compared to clinical correlates at baseline and after treatment.

KEY RESULTS

Forty patients (pooled FFED + FFED + AAF) (60% male, age 34.5 (interquartile range [IQR] 29-42.8 years) completed the diet. Peak eosinophil counts/hpf, symptoms and endoscopic signs were significantly decreased after 6 weeks dietary treatment. DSG-1 levels were significantly upregulated from baseline to week 6, whereas IL-13, CAPN-14, IL-5, IL-10, CCL-26, POSTN, TSLP, CPA-3, and TGF-β were significantly downregulated after 6 weeks of diet (all; <0.01). Prior to treatment, upregulation of CAPN-14 and lower levels of DSG-1 were associated with clinical fibrotic phenotypes, whereas upregulation of IL-10 was linked to food impaction phenotypes.

CONCLUSION

These findings strongly suggest that elimination diets, besides a clinical and histological response, are associated with a broad transcriptional response at the level of the esophageal epithelium.

Eosinophilic esophagitis auxiliary diagnosis based on a peptide ligand to eosinophil cationic protein in esophageal mucus of pediatric patients

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition of the esophagus characterized by increased number of eosinophils. Currently, EoE diagnosis is based on endoscopic procedures for histopathological examination, eosinophils' counting and, often, in clinical practice, the challenge is the differentiation between EoE and gastroesophageal reflux disease (GERD). Our aim was to develop novel peptide ligand to Eosinophil cationic protein (ECP) present in EoE biopsies of patients with potential to be used for detection. We performed a comparative proteomic analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) of esophageal biopsies from pediatric patients with eosinophilic esophagitis, gastroesophageal reflux disease and control individuals. Then, phage display technology was used to select peptides against specific up-regulated protein from EoE patients. Twelve phage clones were selected after three biopanning rounds, and the best phage clone reactivity was evaluated by phage-ELISA assay using esophageal mucus samples from 94 pediatric patients. Mass spectrometry showed that eosinophil cationic protein (ECP) was one of the most up-regulated proteins in EoE patients, which is an eosinophil granule protein usually deposited on tissues to mediate remodeling, but in excess may cause fibrosis and hypertrophy, especially in allergic responses. A highly reactive ECP-ligand peptide (E5) was able to distinguish reactive mucus of EoE patients from GERD and the control individuals by Phage-ELISA, achieving a sensitivity of 84.62%, and a specificity of 82.72%. This is the first study that successfully demonstrated an antibody-like peptide targeting ECP at the esophagus mucus as a useful auxilliary tool for EoE diagnosis with a significant association with atopic disorders and dysphagia.ClinicalTrials.gov no.: NCT03069573.

Butyrate and propionate restore interleukin 13-compromised esophageal epithelial barrier function

BACKGROUND

Eosinophilic esophagitis (EoE) is a food allergen driven disease that is accompanied by interleukin (IL) 13 overexpression and esophageal barrier dysfunction allowing transepithelial food allergen permeation. Nutraceuticals, such as short-chain fatty acids (SCFAs) that restore barrier function and increase immune fitness may be a promising tool in the management of EoE. Here, we investigated the effects of the SCFAs acetate, propionate, and butyrate on an IL-13-compromised human esophageal epithelial barrier, including the mechanisms involved.

METHODS

An air-liquid interface culture model of differentiated human EPC2-hTERT (EPC2) was used to study whether SCFAs could restore barrier function after IL-13-induced impairment. Esophageal epithelial barrier function was monitored by transepithelial electrical resistance (TEER) and FITC-dextran paracellular flux, and was further examined by qPCR and immunohistochemical analysis. G protein-coupled receptor (GPR) GPR41, GPR43, GPR109a, or histone deacetylase (HDAC) (ant)agonists were used to assess mechanisms of action of SCFAs.

RESULTS

IL-13 stimulation decreased TEER and increased FITC flux, which was counteracted by butyrate and propionate, but not acetate treatment. Barrier proteins FLG and DSG1 mRNA expression was upregulated following butyrate and propionate treatment, whereas expression of eosinophil chemoattractant CCL26 and protease CAPN14 was downregulated. Similarly, butyrate and propionate restored FLG and DSG1 protein expression. Similar effects were observed with an HDAC antagonist but not with GPR agonists.

CONCLUSION

Nutraceuticals butyrate and propionate restore the barrier function of esophageal epithelial cells after an inflammatory insult and may be of therapeutic benefit in the management of EoE.

Budesonide Oral Suspension Improves Outcomes in Patients With Eosinophilic Esophagitis: Results from a Phase 3 Trial

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated disease for which there is currently no pharmacologic therapy approved by the US Food and Drug Administration.

METHODS

In this double-blind, placebo-controlled, phase 3 trial, patients 11-55 years of age with EoE and dysphagia were randomized 2:1 to receive budesonide oral suspension (BOS) 2.0 mg twice daily or placebo for 12 weeks at academic or community care practices. Co-primary endpoints were the proportion of stringent histologic responders (≤6 eosinophils/high-power field) or dysphagia symptom responders (≥30% reduction in Dysphagia Symptom Questionnaire [DSQ] score) over 12 weeks. Changes in DSQ score (key secondary endpoint) and EoE Endoscopic Reference Score (EREFS) (secondary endpoint) from baseline to week 12, and safety parameters were examined.

RESULTS

Overall, 318 patients (BOS, n = 213; placebo, n = 105) were randomized and received ≥1 dose of study treatment. More BOS-treated than placebo-treated patients achieved a stringent histologic response (53.1% vs 1.0%; Δ52% [95% confidence interval (CI), 43.3%-59.1%]; P < .001) or symptom response (52.6% vs 39.1%; Δ13% [95% CI, 1.6%-24.3%]; P = .024) over 12 weeks. BOS-treated patients also had greater improvements in least-squares mean DSQ scores and EREFS over 12 weeks than placebo-treated patients: DSQ, -13.0 (SEM 1.2) vs -9.1 (SEM 1.5) (Δ-3.9 [95% CI, -7.1 to -0.8]; P = .015); EREFS, -4.0 (SEM 0.3) vs -2.2 (SEM 0.4) (Δ-1.8 [95% CI, -2.6 to -1.1]; P < .001). BOS was well tolerated; most adverse events were mild or moderate in severity.

CONCLUSIONS

In patients with EoE, BOS 2.0 mg twice daily was superior to placebo in improving histologic, symptomatic, and endoscopic outcomes over 12 weeks. BOS 2.0 mg twice daily was well tolerated. ClinicalTrials.gov number: NCT02605837.

From Allergy to Cancer-Clinical Usefulness of Eotaxins

Simple Summary

Eotaxins are small proteins included in the group of chemokines. They act mainly on blood cells called eosinophils which are involved in the pathogenesis of inflammatory processes. This connection leads to involvement of eotaxins in the pathogenesis of all inflammatory related diseases, such as allergic diseases and cancer. This paper summarizes the current knowledge about eotaxins, showing their usefulness as markers that can be used not only in the detection of these diseases, but also to determine the effectiveness of treatment.

Abstract

Eotaxins are proteins which belong to the group of cytokines. These small molecules are secreted by cells that are mainly involved in immune-mediated reactions in the course of allergic diseases. Eotaxins were discovered in 1994 and their main role was considered to be the selective recruitment of eosinophils. As those blood cells are involved in the course of all inflammatory diseases, including cancer, we decided to perform an extensive search of the literature pertaining to our investigation via the MEDLINE/PubMed database. On the basis of available literature, we can assume that eotaxins can be used as markers for the detection and determination of origin or type of allergic disease. Many publications also confirm that eotaxins can be used in the determination of allergic disease treatment. Moreover, there are also studies indicating a connection between eotaxins and cancer. Some researchers revealed that CCL11 (C-C motif chemokine ligand 11, eotaxin-1) concentrations differed between the control and tested groups indicating their possible usefulness in cancer detection. Furthermore, some papers showed usefulness of eotaxins in determining the treatment efficacy as markers of decreasing inflammation. Therefore, in this paper we present the current knowledge on eotaxins in the course of allergic and cancerous diseases.

Endoscopy in Pediatric Eosinophilic Esophagitis

Endoscopy and mucosal biopsies are essential to the diagnosis of EoE. Together they either confirm or exclude mucosal eosinophilia and provide a visual inspection of the esophagus that may be consistent with EoE or suggest other underlying etiologies. Endoscopy also plays an important therapeutic role in the management of EoE including the assessment of treatment response and treatment of associated complications including esophageal stricture and food impaction. Assessment of treatment response largely depends on endoscopy and mucosal biopsies although less invasive strategies may eventually provide alternative means to assess mucosal inflammation. Herein we will review current use of endoscopy in EoE, including recently developed technologies and their role in the management of EoE.

Relationship of the Esophageal Microbiome and Tissue Gene Expression and Links to the Oral Microbiome: A Randomized Clinical Trial

INTRODUCTION

Although the microbiome is altered in various esophageal diseases, there is no direct evidence for a link between the oral or esophageal microbiome and underlying esophageal tissue. Here, we aimed to address these gaps through use of an antimicrobial mouth rinse to modify the esophageal microbiome and tissue gene expression.

METHODS

In this randomized controlled trial, patients scheduled to undergo endoscopy for clinical indications used chlorhexidine mouth rinse or no treatment for 2 weeks before endoscopy. Oral swabs and saliva were collected at baseline and at follow-up, and the esophagus was sampled on the day of endoscopy. The microbiome was analyzed by 16S rRNA gene sequencing, and esophageal tissue gene expression was ascertained by RNA-Seq.

RESULTS

Twenty subjects were enrolled and included in the analyses. Within individuals, the oral and esophageal microbiome composition was significantly correlated. Chlorhexidine treatment associated with significant alterations to the relative abundance of several esophageal bacterial taxa, and to expression of genes in the esophagus including reductions in periostin, claudin-18, chemokines CXCL1 and CXCL13, and several members of the tumor necrosis factor receptor superfamily. A taxon in genus Haemophilus in the esophagus also associated with significant changes in tissue gene expression.

DISCUSSION

The oral and esophageal microbiomes are closely related within individuals, and esophageal microbiome alterations correlate with tissue gene expression changes. The esophageal microbiome may act as an important cofactor that influences pathogenesis and outcomes of diseases such as eosinophilic esophagitis, gastroesophageal reflux, and Barrett's esophagus.

Recent insights on the use of topical steroids in eosinophilic esophagitis

INTRODUCTION

Eosinophilic Esophagitis (EoE) is an immune-mediated, chronic inflammatory disorder of the esophagus. Topical steroids have been used in the management of EoE for over 15 years. However, there are no Food and Drug Administration (FDA) approved drug therapies for EoE.

AREAS COVERED

This review discusses the current understanding of EoE and the role of topical steroids in the induction and maintenance of remission in patients with EoE. We performed a comprehensive review of the literature, summarized randomized control trials from 2006 to 2020, and provided a simplified management algorithm for EoE.

EXPERT OPINION

In patients with EoE, topical steroids are effective in inducing clinical and histologic remission. Formulations of topical steroids that maximize the exposure to esophageal mucosa have the highest efficacy. A majority of patients who achieve remission with topical steroids develop clinical and histologic relapse off therapy within a year. Current evidence suggests that maintenance therapy with long-term topical steroids decreases the risk of relapse and progression to fibrostenotic disease. While uncertainty over the dose and duration of maintenance topical steroids and their potential side effects exists, long-term maintenance therapy with topical steroids appears to be the way forward to improve long-term outcomes in patients with EoE.

Management of Eosinophilic Esophagitis: Dietary and Nondietary Approaches

Eosinophilic esophagitis (EoE) is an allergen-driven chronic inflammatory condition, characterized by symptoms related to esophageal dysfunction and confirmed histologically by esophageal mucosal eosinophilia. Since its first description in the 1990s, the incidence and prevalence of EoE have been on the rise. It is known to affect all ages of various ethnic backgrounds and both sexes; however, it is most seen in White males. Children with EoE often present with abdominal pain, nausea, vomiting, and failure to thrive, whereas adults with EoE typically present with dysphagia and food impaction. Diagnosis of EoE requires histologic confirmation of elevated esophageal eosinophils in a symptomatic patient, and only after secondary causes have been excluded. Because EoE is a chronic and progressively fibrostenotic disease, treatment goals include resolution of symptoms, induction and maintenance of disease remission, and prevention and possibly reversal of fibrostenotic complications, while minimizing treatment-related adverse effects and improving quality of life. Treatment strategies include the "3 D's"-drugs, diet, and dilation. Standard drug therapies include proton-pump inhibitors and topical corticosteroids. Dietary therapies include elemental diet, allergy testing-directed elimination diet, and empiric elimination diets. Endoscopic esophageal dilation for EoE strictures can alleviate esophageal symptoms but has no effect on mucosal inflammation. Recent progress in EoE research has made possible evidence-based clinical guidelines. Ongoing pharmacologic trials show promise for novel biologic agents in the treatment of refractory EoE.

Eosinophilic Esophagitis: Update on Diagnosis and Treatment in Pediatric Patients

Eosinophilic esophagitis (EoE) is a chronic immune-mediated inflammatory disorder characterized by symptomatic esophageal dysfunction and an eosinophil-predominant inflammation of the esophagus. EoE arises from interaction between genetic and environmental factors. In pediatric patients, clinical manifestations vary depending on age, from a gastroesophageal reflux disease (GERD)-like condition to severe dysphagic symptoms. Upper endoscopy is considered the gold standard for diagnosis and monitoring of EoE; however, significant efforts are underway to identify noninvasive diagnostic tools and biomarkers to avoid repetitive invasive procedures. Therapeutic first-line options currently available for EoE are elimination diets, proton pump inhibitors (PPIs), and steroids. The aim of treatment is to improve clinical symptoms while obtaining mucosal healing and avoiding long-term complications. Dietary treatment options comprise different empiric diets or an exclusively amino acid formula. Despite the efficacy of diets, compliance is often challenging. PPIs and topical steroids represent the main pharmacological options for EoE, and both can induce and maintain remission. Topical steroids have been reported as more effective, but data on long-term safety remain insufficient for both these and PPIs. Endoscopic dilations are currently reserved for severe untreated fibrostenotic disease unresponsive to medical therapies. Several biologic agents are available but not yet approved for EoE.

Technical review on the management of eosinophilic esophagitis: a report from the AGA institute and the joint task force on allergy-immunology practice parameters

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition of the esophagus. Many new studies have been reported recently that describe EoE management. An expert panel was convened by the American Gastroenterological Association Institute and the Joint Task Force on Allergy-Immunology Practice Parameters to provide a technical review to be used as the basis for an updated clinical guideline. This technical review was developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. Eighteen focused EoE management questions were considered, with 15 answered using the GRADE framework and 3 with a narrative summary. There is moderate certainty in the evidence that topical glucocorticosteroids effectively reduce esophageal eosinophil counts to <15 per high-power field over a short-term treatment period of 4-12 weeks, but very low certainty about the effects of using topical glucocorticosteroids as maintenance therapy. Multiple dietary strategies may be effective in reducing esophageal eosinophil counts to <15 per high-power field over a short-term treatment period, with moderate certainty for elemental diets, low certainty for empiric 2-, 4-, and 6-food elimination diets, and very low certainty that allergy-based testing dietary eliminations have a higher failure rate compared to empiric diet elimination. There is very low certainty for the effect of proton pump inhibitors in patients with esophageal eosinophilia. Although esophageal dilation appears to be relatively safe, there is no evidence that it reduces esophageal eosinophil counts. There is very low certainty in the effects of multiple other medical treatments for EoE: anti-interleukin-5 therapy, anti-interleukin-13 therapy, anti-IgE therapy, montelukast, cromolyn, and anti-TNF therapy.

Technical Review on the Management of Eosinophilic Esophagitis: A Report From the AGA Institute and the Joint Task Force on Allergy-Immunology Practice Parameters

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition of the esophagus. Many new studies have been reported recently that describe EoE management. An expert panel was convened by the American Gastroenterological Association Institute and the Joint Task Force on Allergy-Immunology Practice Parameters to provide a technical review to be used as the basis for an updated clinical guideline. This technical review was developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. Eighteen focused EoE management questions were considered, with 15 answered using the GRADE framework and 3 with a narrative summary. There is moderate certainty in the evidence that topical glucocorticosteroids effectively reduce esophageal eosinophil counts to <15 per high-power field over a short-term treatment period of 4-12 weeks, but very low certainty about the effects of using topical glucocorticosteroids as maintenance therapy. Multiple dietary strategies may be effective in reducing esophageal eosinophil counts to <15 per high-power field over a short-term treatment period, with moderate certainty for elemental diets, low certainty for empiric 2-, 4-, and 6-food elimination diets, and very low certainty that allergy-based testing dietary eliminations have a higher failure rate compared to empiric diet elimination. There is very low certainty for the effect of proton pump inhibitors in patients with esophageal eosinophilia. Although esophageal dilation appears to be relatively safe, there is no evidence that it reduces esophageal eosinophil counts. There is very low certainty in the effects of multiple other medical treatments for EoE: anti-interleukin-5 therapy, anti-interleukin-13 therapy, anti-IgE therapy, montelukast, cromolyn, and anti-TNF therapy.

Allergic Comorbidity in Eosinophilic Esophagitis: Mechanistic Relevance and Clinical Implications

Allergic eosinophilic esophagitis (EoE) is a chronic, allergen-mediated inflammatory disease of the esophagus, and the most common cause of prolonged dysphagia in children and young adults in the developed world. While initially undistinguished from gastroesophageal reflux disease-associated esophageal eosinophilia, EoE is now recognized as a clinically distinct entity that shares fundamental inflammatory features of other allergic conditions and is similarly increasing in incidence and prevalence. The clinical and epidemiologic associations between EoE and other allergic manifestations are well established. In addition to exaggerated rates of atopic dermatitis, IgE-mediated food allergy, asthma, and allergic rhinitis in EoE patients, each of these allergic manifestations imparts individual and cumulative risk for subsequent EoE diagnosis. As such, EoE may be a member of the "allergic march"-the natural history of allergic manifestations during childhood. Several determinants likely contribute to the relationship between these conditions, including shared genetic, environmental, and immunologic factors. Herein, we present a comprehensive review of allergic comorbidity in EoE. We discuss areas of the genome associated with both EoE and other allergic diseases, including the well-studied variants encoding thymic stromal lymphopoietin and calpain 14, among other "atopic" regions. We summarize ways that environmental factors (such as microbiome-altering pressures and aeroallergen exposure) may predispose to multiple allergic conditions including EoE. Finally, we touch on some fundamental features of type 2 inflammation, and the resulting implications for the development of multiple allergic manifestations. We conclude with an analysis of the "type 2" biologics, and how mechanistic similarities between EoE and the other allergic manifestations have important implications for screening and treatment of the allergic patient.

Molecular basis and cellular mechanisms of eosinophilic esophagitis for the clinical practice

Eosinophilic esophagitis (EoE) is a chronic, allergen-driven inflammatory esophageal disease characterized by predominantly eosinophilic inflammation leading to esophageal dysfunction. Recent efforts to understand EoE have increased our knowledge of the disease. Areas covered: Multiple cells, molecules, and genes interplay with early life environmental factors in the pathophysiology of EoE to converge in the esophageal epithelium at the center of disease pathogenesis. Epithelial cells constitute a mayor cytokine source for TSLP and Calpain-14; an impaired epithelial barrier function allowing penetration of food and microbiota-derived antigens is involved in triggering and maintaining inflammation. Eosinophil and mast cell-derived products, including TGFβ, together with IL-1β and TNFα, promote epithelial mesenchymal transition in EoE, contributing to tissue remodeling by synthetizing and depositing extracellular matrix in subepithelial layers. This article aims to provide a state-of-the-art update on the pathophysiology of EoE applied to clinical practice, and latest research and developments with potential interest to improve the diagnosis and treatment of patients with EoE are revised. Expert commentary: Preliminary approaches have provided promising results toward incorporating minimally invasive methods for patient diagnosis and monitoring in clinical practice. Early diagnosis and optimized therapies will allow for personalized medicine in EoE.

Interleukin 9 Alters Epithelial Barrier and E-cadherin in Eosinophilic Esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic TH2-assocated inflammatory condition accompanied by substantial impairments in epithelial barrier function and increased numbers of interleukin 9 (IL-9) expressing inflammatory cells. While IL-9 is known to affect barrier function in the intestine, the functional effects of IL-9 on the esophagus are unclear. Herein we aimed to understand the expression of the IL-9 receptor and effects of IL-9 on the epithelium in EoE.

METHODS

We used esophageal biopsies from pediatric EoE patients with active and inactive disease to analyze the expression of the IL-9 receptor, the adherens junction protein E-cadherin and the tight junction protein claudin-1. We treated primary human esophageal epithelial cells with IL-9 to understand its effects on E-cadherin expression and function.

RESULTS

Active EoE subjects had increased epithelial expression of IL-9 receptor mRNA and protein (P < 0.05) and decreased membrane bound E-cadherin (P < 0.01) and claudin-1 (P < 0.05) expression. IL-9 receptor expression and mislocalized claudin-1 positively correlated and while membrane bound E-cadherin expression negatively correlated with the degree of histologic epithelial remodeling (P < 0.05). IL-9 decreased epithelial resistance in stratified primary human esophageal epithelial cells (P < 0.01) and membrane bound E-cadherin in epithelial cell monolayers (P < 0.01).

CONCLUSIONS

These data suggest that IL-9, its receptor, and its effects on E-cadherin may be important mechanisms for epithelial barrier disruption in EoE.

Filaggrin and tight junction proteins are crucial for IL-13-mediated esophageal barrier dysfunction

Eosinophilic esophagitis (EoE) is an allergy-mediated disease that is accompanied by IL-13 overexpression and an impaired esophageal barrier. Filaggrin (FLG) and tight junction (TJ) proteins are considered to contribute to epithelial barrier function. However, their functional involvement in EoE has not been elucidated. Here, we aimed to determine the IL-13-mediated barrier dysfunction and expression of TJ-related proteins in EoE and to characterize interactions among TJ-related proteins involved in the barrier function of the esophageal epithelium. Biopsy specimens from EoE patients were analyzed. Primary human esophageal epithelial cells (HEECs) were cultured using an air-liquid interface (ALI) system. The permeability of TJs was assayed by biotinylation. Transepithelial electrical resistance (TEER) was measured after stimulation with IL-13 and after siRNA silencing of FLG expression. FLG and TJ genes and proteins were assessed by quantitative RT-PCR, Western blot analysis, and immunofluorescent staining. The biotinylation reagent diffused through the paracellular spaces of whole stratified epithelial layers in EoE biopsy samples. The TEER decreased in ALI-cultured HEECs after IL-13 stimulation. Although the protein level of FLG decreased, that of the TJ proteins increased in the mucosa of EoE biopsy samples and in ALI-cultured HEECs after IL-13 stimulation. IL-13 altered the staining patterns of TJ proteins and the epithelial morphology. FLG siRNA transfection significantly decreased TEER. The IL-13-mediated reduced esophageal barrier is associated with the altered expression pattern but not with the levels of TJ-associated proteins. A deficiency of FLG altered the stratified epithelial barrier. NEW & NOTEWORTHY Esophageal permeability to small molecules was increased in patients with eosinophilic esophagitis (EoE) and could be induced by IL-13 in our unique air-liquid interface-cultured primary multilayer human esophageal epithelial cells in vitro. A deficiency of filaggrin disrupted the esophageal stratified epithelial barrier. The decreased esophageal barrier in EoE was associated with the altered staining pattern of tight junction proteins, although the levels of the proteins themselves do not appear to be changed.

Eosinophilic Esophagitis and the Eosinophilic Gastrointestinal Diseases: Approach to Diagnosis and Management

The eosinophilic gastrointestinal diseases (EGIDs) represent disorders of the gastrointestinal (GI) tract that result from the local infiltration and aberrant activity of eosinophils and other immune cells. Eosinophilic esophagitis (EoE) is the most well-characterized EGID and is defined by the presence of intraepithelial eosinophils in the esophagus (≥15 eosinophils per high-powered field) and clinical symptoms associated with esophageal dysfunction. The other EGIDs are rare and lack strong data regarding pathogenesis and management. The incidence and prevalence of EoE are increasing, and EoE is now a major cause of upper GI morbidity. Management is multidisciplinary, with collaboration between gastroenterologists, allergists, pathologists, and dieticians, and is aimed at amelioration of symptoms and prevention of long-term complications such as esophageal stricture. Treatment options for EoE include proton pump inhibitors, swallowed topical corticosteroids, and elimination diets. Esophageal dilation is used when esophageal strictures or fibrostenotic changes are present. Additional therapies targeting eosinophils and other mediators of Th2 inflammation are under development and are promising. Treatment options for other EGIDs typically involve corticosteroids or dietary elimination.

Systematic review of histological remission criteria in eosinophilic esophagitis

Elemental diets, dietary elimination, and steroid therapies are the most common therapies in the clinical trials for eosinophilic esophagitis (EoE). Histological findings (usually reported as eosinophils per microscopic high‐powered field [hpf]) remain the most common end‐point used to define response. Yet, the threshold for defining “response” and “remission” are ill‐defined among consensus guidelines and may vary from study to study. We conducted a systematic literature review of articles on eosinophilic esophagitis, published between January 2007 and November 2017, considering histological remission as the primary outcome. We abstracted treatment information and definitions of histological remission or response. A comparison of definitions of histological remission across and within institutions was performed. A total of 61 articles were included in this review, with approximately 60% of the studies published from centers in the United States. Histological definitions of remission of EoE ranged from 0 to ≤20 eosinophils/hpf. The most stringent criteria, ranging from 0 to ≤5 eosinophils/hpf, were commonly used in interventional trial studies that examined the effects of new treatments. We found remarkable variability in definitions between studies, treatment types, and regions. Age or epidemiological distribution of study subjects did not influence the criteria for histological remission. Clinical and histological improvements are important measures of the effects of treatment. Histological findings, the most objective measure of treatment, should provide an optimal method for comparing the effectiveness of various treatments. Yet, our findings suggest a lack of consistent remission criteria in published studies. Considering these inconsistencies, it is difficult to compare the effectiveness of various treatments.

Emerging drugs for eosinophilic esophagitis

INTRODUCTION

Eosinophilic esophagitis (EoE) is rare but incidence and prevalence is increasing. EoE is characterized by eosinophilic inflammation of the esophagus causing gastrointestinal symptoms such as abdominal pain, vomiting, reflux, dysphagia, and food impactions. If untreated, remodeling and fibrosis of the esophagus can occur and stricture formation may result. Current treatment options are limited to food-restriction diets or medications including proton pump inhibitors (PPIs) or swallowed corticosteroids. Significant progress has been made in understanding the underlying mechanisms of EoE allowing for development of drugs that target specific points in EoE pathways. Investigation of these drugs is early with few controlled studies, but many show promise as future treatments. Areas covered: This review will provide an up to date discussion of current therapies and investigational drugs for EoE. Articles used in this review were retrieved from PubMed. Ongoing or completed clinical trials were obtained through clinicaltrials.gov and review of the PharmaProjects database. Expert Opinion: Multiple therapeutic targets have been identified and several have shown efficacy. Work is needed to define appropriate trial outcome measures. Collaboration between government agencies, patient advocacy groups, and investigator-led consortia is critical for completing new clinical trials which should pave the way for new therapies in clinical practice.

Biological therapies for eosinophilic gastrointestinal diseases

The scientific basis and the clinical application of mAb therapies that target specific immunologic pathways for eosinophilic gastrointestinal diseases are areas of active interest. There is a growing recognition of a subset of patients with eosinophilic esophagitis whose disease does not respond well to topical steroids or elimination diets. In addition, long-term use of corticosteroids presents possible risks that are currently being evaluated. Systemic therapy with a biologic agent offers potential advantages as a global approach that could limit the need for multiple, locally active medical therapies and allergen avoidance. The identification of novel biologic strategies is ongoing, and the recent validation of instruments and outcome measures to assess disease activity has proved essential in demonstrating efficacy. Studies using biologics that target IL-13 pathways in the treatment of eosinophilic esophagitis have demonstrated substantial promise.

A reduced esophageal epithelial integrity in a subgroup of healthy individuals increases with proton pump inhibitor therapy

INTRODUCTION

Approximately 30% of healthy volunteers (HVs) show dilated intercellular spaces in the esophageal epithelium suggesting a functionally reduced epithelial integrity. We aimed to evaluate the presence of an altered epithelial integrity in HVs and whether physiological acid could explain such a difference.

METHODS

Biopsies for Ussing chamber experiments were taken between 3 cm and 5 cm proximal to the gastroesophageal junction. Twenty-four-hour impedance-pH (MII-pH) monitoring was performed in the same 15 HVs. MII-pH tracings from 24 HVs before and after treatment with esomeprazole (40 mg b.i.d., two weeks), a proton pump inhibitor, were analyzed. Reflux parameters and impedance baseline (IB) at different levels of the esophagus were calculated.

RESULTS

Epithelial integrity in the distal esophagus presents a large variability in vivo and in vitro (transepithelial electrical resistance 196.9 ± 16.27Ω. cm2; IB measurements 2022 ± 143.5Ω). Esomeprazole highly suppressed the total acid exposure time (AET) (1.9 (0.8-3.1) vs 0 (0-0)%, p < 0.0001). After splitting our participants into "high" and "low" IB, based on the median value, we observed only in the distal esophagus a higher total AET before (2.8 (1.6-4.8) vs 1.0 (0.5-2.2), p = 0.04) and increased IB values after esomeprazole (1620 (1347-1898) vs 2192 (1784-2503)Ω, p = 0.002) in the "low" IB group.

CONCLUSION

A subgroup of HVs presents a low epithelial integrity in the distal esophagus probably due to the increased presence of physiological acid reflux. Whether these individuals have a higher chance to develop gastroesophageal reflux disease is unknown. The role of epithelial integrity in symptom perception needs to be further explored.

The Esophageal Epithelial Barrier in Health and Disease

Dysfunction in the esophageal epithelial barrier function is a major source for morbidity. To better understand the pathophysiologic pathways of the diseases associated with barrier dysfunction, including gastroesophageal reflux disease, eosinophilic esophagitis, Barrett's esophagus, and obesity, it is important to understand the esophageal epithelial embryologic development, microscopic anatomy with a special focus on the barrier structure and function, extraepithelial defense mechanisms, and how these change in the diseased state. In recent years, significant progress has been made in elucidating the esophageal barrier structure and function both in vitro and in vivo. This has enhanced the understanding of mechanisms of disease, and may also allow identification of therapeutic targets that can help in the management of these diseases. This review provides a detailed discussion regarding the esophageal epithelial barrier structure and function, the current and historical techniques used to study the barrier, and how it is affected by common esophageal diseases.

Toll-like receptors-mediated pathways activate inflammatory responses in the esophageal mucosa of adult eosinophilic esophagitis

Objectives

Esophageal microbiota and regulation of adaptive immunity are increasingly being investigated in eosinophilic esophagitis (EoE). Toll-like receptors (TLRs) play a central role in the initiation and maintenance of innate immune activity. Our objective was to characterize the esophageal and duodenal innate immune response in EoE and its modulation by dietary therapy.

Methods

Esophageal and duodenal biopsy samples were collected from 10 adults with untreated EoE, before and after effective treatment with a six-food elimination diet (SFED), and 10 controls with normal esophagus. In all cases, bacterial load (by mRNA expression of 16S), TLRs, mucins, transcription factors, interleukins, components of the NKG2D system, and innate immunity effectors were assessed by qPCR. Protein expression of TLRs were also determined by immunofluorescence.

Results

Bacterial load and TLR1, TLR2, TLR4, and TLR9 were overexpressed on biopsies with active EoE compared with controls. Muc1 and Muc5B genes were downregulated while Muc4 was overexpressed. Upregulation of MyD88 and NFκB was found together with IL-1β, IL-6, IL-8, and IL-10 mediators and PER-1, iNOS, and GRZA effectors. NG-K2D components (KLRK1, IL-15, MICB) were also upregulated. In all cases, changes in active EoE were normalized following SFED and mucosal healing. Duodenal samples also showed increased expressions of TLR-1, TLR-2, and TLR-4, but not 16S or any other mediators nor effectors of inflammation.

Conclusions

Esophageal TLR-dependent signaling pathways in EoE support the potential implication of microbiota and the innate immune system in the pathogenesis of this disease.

Eosinophilic Esophagitis Is an Underlying Cause for Gastrointestinal Concerns in Children

Eosinophilic esophagitis (EoE) is a chronic immune antigen-mediated disorder characterized by symptoms of esophageal dysfunction in combination with dense esophageal eosinophilia. The clinical presentation of EoE can vary depending on children's age and their ability to report symptoms, therefore a high index of suspicion for EoE is required because children and teenagers may develop coping strategies around eating. The development of symptoms measurement tools in EoE assists in not only assessing symptoms, but also coping strategies children may have developed. While the diagnosis of EoE requires endoscopic evaluation with histologic assessment of esophageal mucosal biopsy samples, several emerging methods to assess and survey the esophageal mucosa have been developed. Advances in the field to better understand the natural history, clinical and molecular features of phenotypes in EoE will be important in considering novel therapeutic options and assessing outcomes.

Diagnosis and Treatment of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a new disease. It is caused by a T-helper type 2 cell response to food antigens in contact with the esophageal mucosa. Although no single feature defines EoE, a constellation of compatible demographic, clinical, endoscopic, and histologic findings establish the diagnosis. Children present with symptoms and endoscopic patterns characteristic of inflammation, whereas adolescents and adults have manifestations of fibrosis and gross esophageal strictures. Clinical and endoscopic scoring systems have helped to standardize diagnosis. There is controversy in EoE research over the optimal endpoint for treatment. Although the most common endpoint is a reduced number of eosinophils in biopsies, changes in symptoms and endoscopic features are becoming important targets of therapy. We should improve our understanding of EoE progression and the need for maintenance therapy, and continue development of diagnostic tools that avoid endoscopy and biopsy analyses to more easily monitor disease activity.

Evidence of an abnormal epithelial barrier in active, untreated and corticosteroid-treated eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic, immune/antigen-mediated disease characterized by symptoms related to esophageal dysfunction and an eosinophil-predominant inflammation. This study has aimed to investigate whether the recently observed sensitization to Candida albicans in patients with EoE is owing to pre-existing disease and its underlying abnormal epithelial barrier or, alternatively, is linked to corticosteroid (CS) therapy.

METHODS

Medical histories, as well as serum and tissue samples of 60 patients with EoE (15 CS naive, 45 with current or previous CS therapy) and 20 controls, stored in the Swiss Eosinophilic Esophagitis Database (SEED) and Biobank, were analyzed. We applied ImmunoCAP to measure IgE levels and immunofluorescence techniques to examine epithelial barrier components.

RESULTS

Patients with EoE had higher total IgE levels and were more frequently sensitized to C. albicans than controls. In EoE tissue specimens, increased numbers of eosinophils and mast cells, a higher expression levels of thymic stromal lymphopoietin (TSLP), cathelicidin, proteases, that is, the kallikreins (KLK)-5 and KLK-7, were observed as compared with controls, while reduced expression of lympho-epithelial Kazal-type-related inhibitor (LEKTI), filaggrin, E-cadherin, claudin, occludin, desmoglein-1 was found, independent of CS therapy. In CS-treated EoE, significantly lower numbers of CD1a+ cells and cathelicidin expression were noted as compared to CS-naive EoE.

CONCLUSION

This study provides further evidence that EoE is associated with an abnormal epithelial barrier and postulates that CS therapy, by reducing innate immune mechanisms, may promote C. albicans colonization and likely subsequent sensitization.

Six-Food Elimination Diet and Topical Steroids are Effective for Eosinophilic Esophagitis: A Meta-Regression

BACKGROUND

Topical corticosteroids or six-food elimination diet is recommended as initial therapy for eosinophilic esophagitis (EoE).

AIMS

We aimed to summarize published manuscripts that report outcomes of these therapies for EoE.

METHODS

We performed a systematic review in MEDLINE, Web of Science, and Embase of published manuscripts describing topical fluticasone, topical budesonide, and six-food elimination diet as therapies for EoE. We conducted meta-analysis of symptom improvement and the change in peak mucosal eosinophil count, with heterogeneity between studies examined with meta-regression analysis.

RESULTS

Systematic review yielded 51 articles that met inclusion criteria. Summary histologic response rates were 68.3% [95% prediction limits (PL) 16.2-96.0%] for fluticasone, 76.8% (95% PL 36.1-95.1%) for budesonide, and 69.0% (95% PL 31.9-91.4%) for six-food elimination diet. Corresponding decreases in eosinophil counts were 37.8 (95% PL 19.0-56.7), 62.5 (95% PL 125.6 to -0.67, and 44.6 (95% PL 26.5-62.7), respectively. Symptom response rates were 82.3% (95% PL 68.1-91.1%), 87.9% (95% PL 42.7-98.6%), and 87.3% (95% PL 64.5-96.3%), respectively. Meta-regression analyses decreased the initially large estimate of residual heterogeneity and suggested differences in histologic response rate associated with study populations' baseline eosinophil count and age.

CONCLUSIONS

The literature describing topical corticosteroids and six-food elimination diet consists of small studies with diverse methods and population characteristics. Meta-analysis with meta-regression shows initial histologic and symptomatic response rates on the same order of magnitude for topical corticosteroids and six-food elimination diet, but heterogeneity of study designs prevents direct comparison of modalities.

Management of Eosinophilic Esophagitis Based on Pathophysiological Evidence

Over the past decades eosinophilic esophagitis (EoE) has been increasingly diagnosed, and significant progress has been made in our understanding of its pathophysiology. As EoE cannot be cured yet, treatment goals are suppression of disease activity and symptoms as well as the prevention of progression to a more severe disease phenotype. Disease-modifying treatment options can be divided into dietary therapy and immunosuppressive medications, of which topical steroids have been most investigated, yet are still prescribed off-label. In this review, we will summarize recent advances in our understanding of EoE and discuss the mechanisms of action of current treatment options, with emphasis on the role of the esophageal epithelial barrier and the effects of proton-pump inhibitors in the management of patients with EoE.

Disease activity in eosinophilic esophagitis is associated with impaired esophageal barrier integrity

In eosinophilic esophagitis (EoE), the esophageal barrier integrity is impaired. Integrity can be assessed with different techniques. To assess the correlations between esophageal eosinophilia and various measures of mucosal integrity and to evaluate whether endoscopic impedance measurements can predict disease activity, endoscopies and mucosal integrity measurements were performed in adult EoE patients with active disease (≥15 eosinophils/high-power field) at baseline (n = 32) and after fluticasone (n = 15) and elemental dietary treatment (n = 14) and in controls (n = 19). Mucosal integrity was evaluated during endoscopy using electrical tissue spectroscopy (ETIS) measuring mucosal impedance and transepithelial electrical resistance (TER) and transepithelial molecule-flux through biopsy specimens in Ussing chambers. We included 61 measurements; 32 of patients at baseline and 29 after treatment, 3 patients dropped out. After treatment, 20 patients were in remission (≤15 eosinophils/high-power field) and these measurements were compared with 41 measurements of patients with active disease (at baseline or after failed treatment). All four mucosal integrity measures showed significant impairment in active EoE compared with remission. Eosinophilia was negatively correlated with ETIS and TER and positively with transepithelial molecule flux (P ≤ 0.001). The optimal ETIS cutoff to predict disease activity was 6,000 Ω·m with a sensitivity of 79% [95% confidence interval (CI) 54-94%], specificity of 84% (95% CI 69-94%), positive predictive values of 89% (95% CI 77-95%) and negative predictive values of 71% (95% CI 54-84%). In EoE patients, markers of mucosal integrity correlate with esophageal eosinophilia. Additionally, endoscopic mucosal impedance measurements can predict disease activity.NEW & NOTEWORTHY In adult patients with eosinophilic esophagitis (EoE), the mucosal integrity, measured by making use of four different parameters, correlates strongly with esophageal eosinophilia. The accuracy of endoscopically measured mucosal impedance to distinguish active disease from remission was acceptable with moderate specificity and sensitivity. Mucosal impedance measurements can predict disease activity in adult EoE patients.

Tissue Remodeling in Chronic Eosinophilic Esophageal Inflammation: Parallels in Asthma and Therapeutic Perspectives

Chronic eosinophilic inflammation is associated with tissue remodeling and fibrosis in a number of chronic T-helper 2 (Th2)-mediated diseases including eosinophilic esophagitis (EoE) and asthma. Chronic inflammation results in dysregulated tissue healing, leading to fibrosis and end organ dysfunction, manifesting clinically as irreversible airway obstruction in asthma and as esophageal rigidity, strictures, narrowing, dysmotility, dysphagia, and food impactions in EoE. Current therapies for EoE and asthma center on reducing inflammation-driven tissue remodeling and fibrosis with corticosteroids, coupled with symptomatic control and allergen avoidance. Additional control of Th2 inflammation can be achieved in select asthma patients with biologic therapies such as anti-IL-5 and anti-IL-13 antibodies, which have also been trialed in EoE. Recent molecular analysis suggests an emerging role for structural cell dysfunction, either inherited or acquired, in the pathogenesis and progression of EoE and asthma tissue remodeling. In addition, new data suggest that inflammation-independent end organ rigidity can alter structural cell function. Herein, we review emerging data and concepts for the pathogenesis of tissue remodeling and fibrosis primarily in EoE and relevant pathogenetic parallels in asthma, focusing additionally on emerging disease-specific therapies and the ability of these therapies to reduce tissue remodeling in subsets of patients.

Esophageal and Small Intestinal Mucosal Integrity in Eosinophilic Esophagitis and Response to an Elemental Diet

OBJECTIVES

The esophageal mucosal integrity is impaired in eosinophilic esophagitis (EoE) and it has been suggested that the duodenal permeability is increased. The absence of food allergens may restore the integrity. The aims of this study were to assess duodenal permeability in EoE and to evaluate the effect of an elemental diet on the esophageal and duodenal integrity.

METHODS

In this prospective study 17 adult EoE patients and 8 healthy controls (HC) were included. Esophageal biopsy specimens were sampled before and after 4 weeks of elemental diet to measure eosinophil counts and gene expression of tight junction and barrier integrity proteins. Esophageal and duodenal impedance were measured by electrical tissue impedance spectroscopy and Ussing chambers were used to measure transepithelial resistance (TER) and transepithelial molecule flux. Small intestinal permeability was measured using a test, measuring lactulose/mannitol (L/M) ratios.

RESULTS

In EoE patients, the esophageal but not the duodenal integrity was impaired, compared with HC. We observed no significant difference between L/M ratios of HC and EoE patients. After diet, eosinophil counts decreased significantly, which was paralleled by normalization of esophageal impedance and transepithelial molecule flux. The esophageal TER improved significantly, but did not reach values seen in HC. Esophageal expression of genes encoding for barrier integrity proteins filaggrin and desmoglein-1 was impaired at baseline and restored after diet.

CONCLUSIONS

An elemental diet restores esophageal integrity, suggesting that it is at least partly secondary to allergen exposure. Duodenal integrity seems not to be affected in EoE, and possibly plays a minor role in its pathophysiology.

Proton pump inhibitor-responsive esophageal eosinophilia: still a valid diagnosis?

PURPOSE OF REVIEW

To update rapidly evolving concepts regarding the controversial entity of 'proton pump inhibitor (PPI)-responsive esophageal eosinophilia,' referring to patients with clinical, endoscopic and histologic features of eosinophilic esophagitis (EoE) who achieve remission on PPI therapy.

RECENT FINDINGS

Up to half of pediatric and adult patients with typical EoE symptoms and histology achieve clinico-pathologic remission on PPI therapy, irrespective of whether esophageal pH monitoring demonstrates abnormal acid reflux. In patients with clinical and histologic features of EoE, genotypic and phenotypic features of PPI responders and nonresponders are virtually indistinguishable, and different from those of patients with gastroesophageal reflux disease. In PPI responders, PPIs effects on esophageal Th2 inflammation and gene expression are similar to those of topical steroids in PPI nonresponders. These therapies, along with diets, recently have been shown to be potentially interchangeable in two small series.

SUMMARY

Proton pump inhibitor-responsive esophageal eosinophilia is an inappropriate disease descriptor, arbitrarily based on a response to a single drug, and should be abandoned. Patients who have esophageal eosinophilia and esophageal symptoms that resolve with PPI therapy have phenotypic, molecular, mechanistic, and therapeutic features indistinguishable from similar patients who do not respond to PPIs. These patients with PPI responsiveness should be considered within the spectrum of EoE.

Cost Utility Analysis of Topical Steroids Compared With Dietary Elimination for Treatment of Eosinophilic Esophagitis

BACKGROUND & AIMS

Topical corticosteroids or dietary elimination are recommended as first-line therapies for eosinophilic esophagitis, but data to directly compare these therapies are scant. We performed a cost utility comparison of topical corticosteroids and the 6-food elimination diet (SFED) in treatment of eosinophilic esophagitis, from the payer perspective.

METHODS

We used a modified Markov model based on current clinical guidelines, in which transition between states depended on histologic response simulated at the individual cohort-member level. Simulation parameters were defined by systematic review and meta-analysis to determine the base-case estimates and bounds of uncertainty for sensitivity analysis. Meta-regression models included adjustment for differences in study and cohort characteristics.

RESULTS

In the base-case scenario, topical fluticasone was about as effective as SFED but more expensive at a 5-year time horizon ($9261.58 vs $5719.72 per person). SFED was more effective and less expensive than topical fluticasone and topical budesonide in the base-case scenario. Probabilistic sensitivity analysis revealed little uncertainty in relative treatment effectiveness. There was somewhat greater uncertainty in the relative cost of treatments; most simulations found SFED to be less expensive.

CONCLUSIONS

In a cost utility analysis comparing topical corticosteroids and SFED for first-line treatment of eosinophilic esophagitis, the therapies were similar in effectiveness. SFED was on average less expensive, and more cost effective in most simulations, than topical budesonide and topical fluticasone, from a payer perspective and not accounting for patient-level costs or quality of life.

Proposed criteria to differentiate heterogeneous eosinophilic gastrointestinal disorders of the esophagus, including eosinophilic esophageal myositis

AIM

To define clinical criteria to differentiate eosinophilic gastrointestinal disorder (EoGD) in the esophagus.

METHODS

Our criteria were defined based on the analyses of the clinical presentation of eosinophilic esophagitis (EoE), subepithelial eosinophilic esophagitis (sEoE) and eosinophilic esophageal myositis (EoEM), identified by endoscopy, manometry and serum immunoglobulin E levels (s-IgE), in combination with histological and polymerase chain reaction analyses on esophageal tissue samples.

RESULTS

In five patients with EoE, endoscopy revealed longitudinal furrows and white plaques in all, and fixed rings in two. In one patient with sEoE and four with EoEM, endoscopy showed luminal compression only. Using manometry, failed peristalsis was observed in patients with EoE and sEoE with some variation, while EoEM was associated with hypercontractile or hypertensive peristalsis, with elevated s-IgE. Histology revealed the following eosinophils per high-power field values. EoE = 41.4 ± 7.9 in the epithelium and 2.3 ± 1.5 in the subepithelium; sEoE = 3 in the epithelium and 35 in the subepithelium (conventional biopsy); EoEM = none in the epithelium, 10.7 ± 11.7 in the subepithelium (conventional biopsy or endoscopic mucosal resection) and 46.8 ± 16.5 in the muscularis propria (peroral esophageal muscle biopsy). Presence of dilated epithelial intercellular space and downward papillae elongation were specific to EoE. Eotaxin-3, IL-5 and IL-13 were overexpressed in EoE.

CONCLUSION

Based on clinical and histological data, we identified criteria, which differentiated between EoE, sEoE and EoEM, and reflected a different pathogenesis between these esophageal EoGDs.

Elemental diet decreases inflammation and improves symptoms in adult eosinophilic oesophagitis patients

BACKGROUND

Eosinophilic oesophagitis (EoE) is a chronic disease, driven by food allergens. Elemental diets are effective for the management of children with EoE, but studies on the effect of elemental diets in adults are scarce and poor palatability challenges dietary adherence.

AIM

To assess the effects of an elemental diet (Neocate, Nutricia, Utrecht, the Netherlands) on the inflammation, symptoms and endoscopic signs in adult EoE patients.

METHODS

In this prospective study, 21 patients with active EoE, confirmed by biopsies showing ≥15 eosinophils per microscopic high power field (HPF) and symptoms of oesophageal dysfunction were included. Patients underwent endoscopy before and 4 weeks after diet. Histological disease activity (peak eosinophil count/HPF), and endoscopic signs were scored by physicians. Symptoms and adherence to the diet were evaluated by questionnaires. Serum total IgE levels and total eosinophil counts were determined and the expression of inflammatory cytokines was analysed by qPCR.

RESULTS

In total, 17 (81%) of the patients completed the diet, of whom 12 (71%) showed complete histological response (≤15 eosinophils/HPF) and 4 (24%) showed partial histological response (≥50% reduction of baseline eosinophil count). Peak eosinophil counts decreased significantly after the diet from 40 to 9 per HPF (P ≤ 0.001). A marked improvement in endoscopic signs was observed. Symptoms decreased significantly in all subjects, and 15 patients (88%) became completely asymptomatic (P ≤ 0.001). In 14 patients (82%), blood eosinophil count and serum IgE decreased (P ≤ 0.05).

CONCLUSION

Elemental diet reduces eosinophilic inflammation and induces clinical remission in adult patients with eosinophilic oesophagitis.

Managing eosinophilic esophagitis: challenges and solutions

Eosinophilic esophagitis (EoE) is a chronic and progressive immune-mediated condition defined by symptoms of esophageal dysfunction and dense eosinophilic infiltration of the esophageal mucosa. Therapies consist of anti-eosinophilic medications and specialized diets aimed to decrease the progression of EoE and alleviate its symptoms, namely, dysphagia and food impaction. Assessing response to therapy remains challenging, as treatment end points are not well defined and currently consist of clinical, histologic, and endoscopic features. Newer validated measures may help standardize treatment end points. Emerging data support the use of maintenance therapy, which may reduce disease progression. Optimal dosages, delivery techniques, and duration of treatment need to be determined. When features of fibrostenosis develop, esophageal dilation is a safe and effective adjunctive strategy for improving symptoms. In EoE cases refractory to conventional treatments, newer therapies targeting inflammatory mediators and cytokines are on the horizon.

Esophageal Impedance Monitoring: Clinical Pearls and Pitfalls

The development of intraluminal esophageal impedance monitoring has improved our ability to detect and measure gastroesophageal reflux without dependence on acid content. This ability to detect previously unrecognized weak or nonacid reflux episodes has had important clinical implications in the diagnosis and management of gastroesophageal reflux disease (GERD). In addition, with the ability to assess bolus transit within the esophageal lumen, impedance monitoring has enhanced the recognition and characterization of esophageal motility disorders in patients with nonobstructive dysphagia. The assessment of the intraluminal movement of gas and liquid has also been proven to be of diagnostic value in conditions such as rumination syndrome and excessive belching. Further, alternative applications of impedance monitoring, such as the measurement of mucosal impedance, have provided novel insights into assessing esophageal mucosal integrity changes as a consequence of inflammatory change. Future applications for esophageal impedance monitoring also hold promise in esophageal conditions other than GERD. However, despite all of the clinical benefits afforded by esophageal impedance monitoring, important clinical and technical shortcomings limit its diagnostic value and must be considered when interpreting study results. Overinterpretation of studies or application of impedance monitoring in patients can have deleterious clinical implications. This review will highlight the clinical benefits and limitations of esophageal impedance monitoring and provide clinical pearls and pitfalls associated with this technology.

Gastrointestinal mucosal barrier function and diseases

The gastrointestinal mucosal barrier plays an essential role in the separation of the inside of the body from the outside environment. Tight junctions (TJs) are the most important component for construction of a constitutive barrier of epithelial cells, and they regulate the permeability of the barrier by tightly sealing the cell-cell junctions. TJ proteins are represented by claudins, occludin, junctional adhesion molecules, and scaffold protein zonula occludens. Among these TJ proteins, claudins are the major components of TJs and are responsible for the barrier and the polarity of the epithelial cells. Gastrointestinal diseases including reflux esophagitis, inflammatory bowel disease, functional gastrointestinal disorders, and cancers may be regulated by these molecules, and disruption of their functions leads to chronic inflammatory conditions and chronic or progressive disease. Therefore, regulation of the barrier function of epithelial cells by regulating the expression and localization of TJ proteins is a potential new target for the treatment of these diseases. Treatment strategies for these diseases might thus be largely altered if symptom generation and/or immune dysfunction could be regulated through improvement of mucosal barrier function. Since TJ proteins may also modify tumor infiltration and metastasis, other important goals include finding a good TJ biomarker of cancer progression and patient prognosis, and developing TJ protein-targeted therapies that can modify patient prognosis. This review summarizes current understanding of gastrointestinal barrier function, TJ protein expression, and the mechanisms underlying epithelial barrier dysregulation in gastrointestinal diseases.

Prospective assessment of serum periostin as a biomarker for diagnosis and monitoring of eosinophilic oesophagitis

BACKGROUND

Periostin is highly expressed in eosinophilic oesophagitis (EoE), but has not been extensively studied as a non-invasive biomarker.

AIM

To assess whether serum periostin distinguished EoE from controls at baseline, had utility for monitoring treatment response, or was associated with IL-13 levels.

METHODS

This was a sub-analysis of a prospective cohort study of adults undergoing out-patient upper endoscopy. Incident cases of EoE were diagnosed per consensus guidelines. Controls were subjects with either GERD or dysphagia without EoE. EoE patients were treated with swallowed/topical steroids and had repeat endoscopy/biopsy. Serum periostin levels for cases and controls were compared at baseline, and pre/post-treatment levels were compared for cases. Serum IL-13 and tissue expression of periostin were also assessed.

RESULTS

A total of 61 incident EoE cases and 87 controls were analysed. Despite a marked increase in tissue periostin expression in cases, the median baseline serum periostin level was only slightly higher in cases than controls (22.1 ng/mL vs. 20.7; P = 0.04); there was no change in post-treatment levels. There was also no difference in serum periostin for cases by histologic response or atopic status. There was a strong trend towards higher serum IL-13 levels in cases in the highest periostin quartile (57.1 pg/mL vs. 2.6; P = 0.07).

CONCLUSIONS

Serum periostin levels were similar in cases and controls, and there were no changes post-treatment. Given elevated IL-13 levels in the EoE patients with the highest periostin levels, future studies could explore periostin as a biomarker in EoE, perhaps in the setting of anti-IL-13 therapy.

2015 David Y. Graham Lecture: The First Two Decades Of Eosinophilic Esophagitis-From Acid Reflux To Food Allergy

Collaborative efforts by pediatric and adult gastroenterologists, allergists, dieticians, and pathologists have brought about marked progress in the recognition, understanding, and management of eosinophilic esophagitis (EoE) over the past two decades. Once an esoteric diagnosis, EoE is now increasingly identified as a major cause of morbidity, afflicting both children and adults. The detection of mucosal eosinophils has evolved from a diagnostic feature of acid reflux to a biomarker of food sensitization of the esophagus. Translational studies and murine models have elucidated Th-2 immune pathways in EoE, inspiring the development of targeted biologic therapeutics. At the same time, validation of patient-reported outcomes and endoscopic end points has facilitated the implementation of clinical trials of novel therapeutics. Ongoing investigations have elucidated the importance of "looking beneath the surface" of the epithelium, focusing greater attention on the impact of esophageal remodeling in the clinical consequences of EoE. Elimination diets continue to gain popularity as an intriguing, highly effective, and non-pharmacologic therapy that lends credence to the concept that EoE is a food-driven, immunologic disorder.

Proton pump inhibitor-responsive oesophageal eosinophilia: an entity challenging current diagnostic criteria for eosinophilic oesophagitis

Consensus diagnostic recommendations to distinguish GORD from eosinophilic oesophagitis (EoE) by response to a trial of proton pump inhibitors (PPIs) unexpectedly uncovered an entity called 'PPI-responsive oesophageal eosinophilia' (PPI-REE). PPI-REE refers to patients with clinical and histological features of EoE that remit with PPI treatment. Recent and evolving evidence, mostly from adults, shows that patients with PPI-REE and patients with EoE at baseline are clinically, endoscopically and histologically indistinguishable and have a significant overlap in terms of features of Th2 immune-mediated inflammation and gene expression. Furthermore, PPI therapy restores oesophageal mucosal integrity, reduces Th2 inflammation and reverses the abnormal gene expression signature in patients with PPI-REE, similar to the effects of topical steroids in patients with EoE. Additionally, recent series have reported that patients with EoE responsive to diet/topical steroids may also achieve remission on PPI therapy. This mounting evidence supports the concept that PPI-REE represents a continuum of the same immunological mechanisms that underlie EoE. Accordingly, it seems counterintuitive to differentiate PPI-REE from EoE based on a differential response to PPI therapy when their phenotypic, molecular, mechanistic and therapeutic features cannot be reliably distinguished. For patients with symptoms and histological features of EoE, it is reasonable to consider PPI therapy not as a diagnostic test, but as a therapeutic agent. Due to its safety profile, ease of administration and high response rates (up to 50%), PPI can be considered a first-line treatment before diet and topical steroids. The reasons why some patients with EoE respond to PPI, while others do not, remain to be elucidated.