Transient PPI responsive esophageal eosinophilia may be a clinical sub-phenotype of pediatric eosinophilic esophagitis

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.

Long-term Outcome of Asymptomatic Esophageal Eosinophilia

Background/Aims

: Asymptomatic esophageal eosinophilia (aEE), characterized by eosinophil infiltration in the esophagus without clinical symptoms, has been reported as a precursor of eosinophilic esophagitis (EoE). Nevertheless, no report exists on the long-term clinical course of the disease. Therefore, this study aimed to investigate the long-term clinical course of aEE over 5 years, including the symptomatic conversion rate and the effect of treatments.

Methods

: We reviewed 28 patients with aEE who had been followed up for over 5 years with endoscopic monitoring. The basal characteristics of patients were compared with those of 58 patients diagnosed with EoE during the same period. Patients' clinicopathological findings were collected and examined.

Results

: No significant differences in basal characteristics and histopathological findings were observed between the patients with aEE and those with EoE. The median follow-up duration was 64 months. Among the 28 patients with aEE, seven were treated with proton pump inhibitor or potassium-competitive acid blocker and the remaining 21 opted for follow-up with no medication. Among the treated patients, six (85.7%) exhibited endoscopic and pathologic improvements. Among the cases followed up without medication, the findings worsened in two (9.5%), improved spontaneously in seven (33.3%), and were unchanged in 12 (57.1%), and three (14.3%) developed symptoms at a mean time of 40 months. Symptoms developed in cases where endoscopic and pathologic findings remained unchanged or worsened during follow-up.

Conclusions

: Some patients with aEE had improved findings without treatment, whereas others developed symptoms, emphasizing the importance of long-term monitoring and individualized treatment decisions.

The 1st EoETALY Consensus on the Diagnosis and Management of Eosinophilic Esophagitis-Current Treatment and Monitoring

The present document constitutes Part 2 of the EoETALY Consensus Statements guideline on the diagnosis and management of eosinophilic esophagitis (EoE) developed by experts in the field of EoE across Italy (i.e., EoETALY Consensus Group). Part 1 was published as a different document, and included three chapters discussing 1) definition, epidemiology, and pathogenesis; 2) clinical presentation and natural history and 3) diagnosis of EoE. The present work provides guidelines on the management of EoE in two final chapters: 4) treatment and 5) monitoring and follow-up, and also includes considerations on knowledge gaps and a proposed research agenda for the coming years. The guideline was developed through a Delphi process, with grading of the strength and quality of the evidence of the recommendations performed according to accepted GRADE criteria.This document has received the endorsement of three Italian national societies including the Italian Society of Gastroenterology (SIGE), the Italian Society of Neurogastroenterology and Motility (SINGEM), and the Italian Society of Allergology, Asthma, and Clinical Immunology (SIAAIC). The guidelines also involved the contribution of members of ESEO Italia, the Italian Association of Families Against EoE.

Eosinophilic esophagitis: Immune mechanisms and therapeutic targets

Eosinophilic esophagitis (EoE) is an emerging chronic inflammatory disease of the oesophagus and is clinically characterized by upper gastrointestinal (GI) symptoms including dysphagia and esophageal food impaction. Histopathologic manifestations, which include intraepithelial eosinophilic inflammation and alterations of the esophageal squamous epithelium, such as basal zone hyperplasia (BZH) and dilated intercellular spaces (DIS), are thought to contribute to esophageal dysfunction and disease symptoms. Corroborative clinical and discovery science-based studies have established that EoE is characterized by an underlying allergic inflammatory response, in part, related to the IL-13/CCL26/eosinophil axis driving dysregulation of several key epithelial barrier and proliferative regulatory genes including kallikrein (KLK) serine proteases, calpain 14 (CAPN14) and anoctamin 1 (ANO1). The contribution of these inflammatory and proliferative processes to the clinical and histological manifestations of disease are not fully elucidated. Herein, we discuss the immune molecules and cells that are thought to underlie the clinical and pathologic manifestations of EoE and the emerging therapeutics targeting these processes for the treatment of EoE.

Proton Pump Inhibitor Therapy for Eosinophilic Esophagitis: History, Mechanisms, Efficacy, and Future Directions

Over the past decade, the role of proton pump inhibitor (PPI) medication has evolved from a diagnostic tool for Eosinophilic Esophagitis (EoE), by excluding patients with PPI responsive esophageal eosinophilia (PPI-REE), to a therapy for EoE. This transition resulted from the Updated International Consensus Diagnostic Criteria for Eosinophilic Esophagitis: Proceedings of the Appraisal of Guidelines for Research and Evaluation II (AGREE) Conference to support PPI therapy for EoE in children and adults. Additional recent advances have suggested a role for genetic variations that might impact response to PPI therapy for EoE. This review article will explore a brief background of EoE, the evolution of PPI therapy for EoE and its proposed mechanisms, efficacy and safety in children and adults, and considerations for future PPI precision medicine in patients with EoE.

Eosinophilic esophagitis, Barrett's esophagus and esophageal neoplasms in the pediatric patient: a narrative review

There are several esophageal disorders that can occur in the pediatric population. Eosinophilic esophagitis (EoE) is an eosinophil predominant inflammatory disease of the esophagus that was first characterized in the early 1900's. EoE is the most common pediatric esophageal inflammatory condition after gastroesophageal reflux disease (GERD). Longstanding GERD is a known risk factor for the development of Barrett's esophagus (BE) in both children and adults. BE is associated with the development of dysplasia and, if left undiagnosed, may progress to the development of esophageal adenocarcinoma (EAC). EAC and esophageal squamous cell carcinoma (ESCC) comprise the majority of childhood esophageal malignant neoplasms. The prevalence of EoE continues to rise within the pediatric population. On the other hand, both BE and esophageal neoplasms remain extremely rare in children. The relationship between a chronic inflammatory condition like EoE to BE and/or esophageal neoplasms remains unclear. The current research of these disease entities is prioritized to further understanding the disease pathogenesis and disease progression, exploring new diagnostic modalities, and developing novel treatments or less invasive therapeutic options. The focus of the following narrative review is to provide a summary of the current clinical practices, future research and their implications on these various esophageal disorders.

Drugs in Focus: Proton Pump Inhibitors

Proton pump inhibitors (PPIs) are amongst the most commonly prescribed drugs in infants and children with the last decades witnessing a dramatic rise in their utilization. Although PPIs are clearly effective when used appropriately and have been regarded as safe drugs, there is growing evidence regarding their potential adverse effects. Although, largely based on adult data it is clear that many of these are also relevant to pediatrics. PPI use potentially affects gastrointestinal microbiota composition and function, decreases defence against pathogens resulting in increased risk for infections, interferes with absorption of minerals and vitamins leading to specific deficiencies and increased risk for bone fractures as well as interferes with protein digestion resulting in increased risk of sensitization to allergens and development of allergic diseases and eosinophilic esophagitis. An association with gastric, liver and pancreatic cancer has also been inferred from adult data but is tenuous and causation is not proven. Overall, evidence for these adverse events is patchy and not always compelling. Overall, the use of PPIs, for selected indications with a good evidence base, has significant potential benefit but carries more caution in infants and children. Pediatricians should be aware of the concerns regarding the potential adverse events associated with their use.

Omeprazole inhibits IgE-mediated mast cell activation and allergic inflammation induced by ingested allergen in mice

BACKGROUND

Patients with eosinophilic esophagitis have increased numbers of mucosal mast cells. Administration of the proton pump inhibitor omeprazole can reduce both esophageal mast cell and eosinophil numbers and attenuate type 2 inflammation in these subjects.

OBJECTIVE

Given that maintenance of an acidic environment within granules is important for mast cell homeostasis, we sought to evaluate the effects of omeprazole on mast cell functions including development, IgE:FcεRI-mediated activation, and responses to food allergen.

METHODS

Mast cell degranulation, cytokine secretion, and early signaling events in the FcεRI pathway, including protein kinase phosphorylation and Ca²⁺ flux, were measured after IgE crosslinking in murine bone marrow-derived mast cells and human cord blood-derived mast cells. The effects of omeprazole on these responses were investigated as was its impact on mast cell-dependent anaphylaxis and food allergy phenotypes in vivo.

RESULTS

Murine and human mast cells treated with omeprazole exhibited diminished degranulation and release of cytokines and histamine in response to allergen. In murine mast cells, phosphorylation of protein kinases, ERK and SYK, was decreased. Differentiation of mast cells from bone marrow progenitors was also inhibited. IgE-mediated passive anaphylaxis was blunted in mice treated with omeprazole as was allergen-induced mast cell expansion and mast cell activation in the intestine in a model of food allergy.

CONCLUSIONS

Our findings suggest that omeprazole targets pathways important for the differentiation and activation of murine mast cells and for the manifestations of food allergy and anaphylaxis.

Approaches and Challenges to Management of Pediatric and Adult Patients With Eosinophilic Esophagitis

Treatment of eosinophilic esophagitis has progressed from elemental formula for children and esophageal dilation for adults to selective exclusion of food triggers and swallowed topical corticosteroids. Management guidelines are available from the American Gastroenterological Association and the Joint Task Force on Allergy Immunology Practice Parameters. We cannot, however, evaluate the efficacy of treatments without a definition of response. We propose a treat-to-target approach, based on symptoms and findings from endoscopy and histology. This approach addresses dissociations between outcomes, such as symptom persistence despite normalization of histologic features and symptom resolution after esophageal dilation despite histologic features of active disease. Eosinophilic esophagitis can now be treated with biologic agents that target specific immune pathways, and findings from prospective trials have indicated that less-restrictive, empiric, elimination diets can be effective and reduce the need for repeated endoscopic assessment of disease activity during food reintroduction. We also discuss eosinophilic esophagitis subtypes, factors associated with disease, and advances in management.

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.

Eosinophilic gastrointestinal diseases - Pathogenesis, diagnosis, and treatment

Eosinophilic gastrointestinal diseases (EGIDs) are divided into eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE), depending on the involved gastrointestinal tract, though both are considered to be chronic Th2-type allergic diseases caused by food or environmental allergens. In development of EoE, refluxed gastric acid may also have an important role. For diagnosis of EGIDs, the presence of symptoms possibly originating from the involved gastrointestinal tract and dense eosinophil infiltration are important factors. Imaging studies, including endoscopy and computed tomography, along with histopathological examinations of biopsy specimens are useful for diagnosis, whereas laboratory testing of blood, urine, and stool samples has limited value. Three useful options for treating EoE patients are acid inhibitors, swallowed topical corticosteroids, and an elimination diet, while systemic administration of glucocorticoids is the standard treatment of EGE, though information is limited. Since the prevalence of EGIDs is increasing in Western countries as well as Japan, development of effective treatments based on sufficient evidence is becoming an urgent need.

Eosinophilic esophagitis: Current concepts in diagnosis and treatment

Eosinophilic esophagitis is an immune-allergic pathology of multifactorial etiology (genetic and environmental) that affects both pediatric and adult patients. Its symptoms, which include heartburn, regurgitation, and esophageal stenosis (with dysphagia being more frequent in eosinophilic esophagitis in young adults and children), are similar to those of gastroesophageal reflux disease, causing delays in diagnosis and treatment. Although endoscopic findings such as furrows, esophageal mucosa trachealization, and whitish exudates may suggest its presence, this diagnosis should be confirmed histologically based on the presence of more than 15 eosinophils per high-power field and the exclusion of other causes of eosinophilia (parasitic infections, hypereosinophilic syndrome, inflammatory bowel disease, among others) for which treatment could be initiated. Currently, the 3 “D”s (“Drugs, Diet, and Dilation”) are considered the fundamental components of treatment. The first 2 components, which involve the use of proton pump inhibitors, corticosteroids, immunosuppressants and empirical diets or guided food elimination based on allergy tests, are more useful in the initial phases, whereas endoscopic dilation is reserved for esophageal strictures. Herein, the most important aspects of eosinophilic esophagitis pathophysiology will be reviewed, in addition to evidence for the various treatments.

Eosinophilic Esophagitis in Esophageal Atresia

Recent studies have reported a higher prevalence of eosinophilic esophagitis in children with esophageal atresia. Under recognition of eosinophilic esophagitis in these patients may lead to excessive use of antireflux therapy and an escalation of interventions, including fundoplication, as symptoms may be attributed to gastroesophageal reflux disease. In addition, long-term untreated eosinophilic esophagitis may lead to recurrent strictures due to transmural esophageal inflammation, necessitating repeated dilatations. Eosinophilic esophagitis should be considered when children with esophageal atresia show persistent symptoms on standard antireflux treatment, increasing dysphagia, and recurrent strictures. Treatment has been found to not only significantly reduce intraepithelial eosinophil count, but also to improve symptoms, and to lower the occurrence of strictures and the need for dilatations. Future prospective studies are warranted in this area.

Updated International Consensus Diagnostic Criteria for Eosinophilic Esophagitis: Proceedings of the AGREE Conference

BACKGROUND & AIMS

Over the last decade, clinical experiences and research studies raised concerns regarding use of proton pump inhibitors (PPIs) as part of the diagnostic strategy for eosinophilic esophagitis (EoE). We aimed to clarify the use of PPIs in the evaluation and treatment of children and adults with suspected EoE to develop updated international consensus criteria for EoE diagnosis.

METHODS

A consensus conference was convened to address the issue of PPI use for esophageal eosinophilia using a process consistent with standards described in the Appraisal of Guidelines for Research and Evaluation II. Pediatric and adult physicians and researchers from gastroenterology, allergy, and pathology subspecialties representing 14 countries used online communications, teleconferences, and a face-to-face meeting to review the literature and clinical experiences.

RESULTS

Substantial evidence documented that PPIs reduce esophageal eosinophilia in children, adolescents, and adults, with several mechanisms potentially explaining the treatment effect. Based on these findings, an updated diagnostic algorithm for EoE was developed, with removal of the PPI trial requirement.

CONCLUSIONS

EoE should be diagnosed when there are symptoms of esophageal dysfunction and at least 15 eosinophils per high-power field (or approximately 60 eosinophils per mm²) on esophageal biopsy and after a comprehensive assessment of non-EoE disorders that could cause or potentially contribute to esophageal eosinophilia. The evidence suggests that PPIs are better classified as a treatment for esophageal eosinophilia that may be due to EoE than as a diagnostic criterion, and we have developed updated consensus criteria for EoE that reflect this change.

Long-term Treatment With Proton Pump Inhibitors Is Effective in Children With Eosinophilic Esophagitis

OBJECTIVES

Proton pump inhibitor (PPI)-responsive eosinophilic esophagitis (EoE) is frequently observed in children, but data on long-term treatment are scarce. The objective of this study is to evaluate the long-term efficacy and safety of PPIs in children with EoE.

METHODS

This prospective study enrolled children with EoE and histological remission to an 8-week esomeprazole trial (1 mg/kg/dose, twice daily). Esomeprazole was maintained at 1 mg/kg/day for 1 year. Symptom recurrence and adverse events were monitored and a follow-up endoscopy was performed at 12 months. Complete histological remission was defined as ≤5 eosinophils/high-power field (eos/hpf), and partial histological remission as >5 and <15 eos/hpf. Patients had no concomitant dietary restrictions or topical steroid.

RESULTS

Fifty-seven children were included. Histological remission on maintenance PPI therapy was present in 40 children (70.1%; 95% CI 56.5-81.5). Long-term remission rate was higher in children with initial complete histological remission than in those with partial remission (81% vs 50%, P = 0.014). Forty-nine children (86%) remained asymptomatic. Pretreatment clinical and histological findings and median PPI dose/kg/day were similar between relapsers and nonrelapsers. Eleven out of 12 children (91.6%) receiving esomeprazole 0.5 mg · kg ·  day for 12 additional months remained in remission. Mild and transient side effects without requiring PPI avoidance were observed in 5 children.

CONCLUSIONS

Up to 70% of children with PPI-responsive EoE remain in histological and clinical remission on a low-dose maintenance treatment at 1-year follow-up, with adequate safety profile. Complete histological remission to an 8-week PPI trial was associated with higher probability of histological remission on maintenance therapy.

Medical and dietary management of eosinophilic esophagitis

OBJECTIVE

Eosinophilic esophagitis (EoE) is a disease of chronic, allergen-driven, T-helper 2 (Th2) immune-mediated inflammation that progresses to fibrostenosis of the esophagus if left untreated. There are currently no Food and Drug Administration (FDA)-approved drugs for the treatment of EoE. This review focuses on the medical and dietary management of EoE.

DATA SOURCES

Manuscripts on EoE treatments were identified on PubMed.

STUDY SELECTIONS

Original research, randomized control trials, retrospective studies, meta-analyses, case series, and on occasions, case reports of high relevance, were selected and reviewed.

RESULTS

Current treatment strategies available to EoE patients center on monotherapy or combination therapy with dietary modification to exclude antigenic stimulation and topical corticosteroids to control Th2-mediated tissue inflammation and pathologic remodeling. Dilation as a rescue therapy for the narrowed, fibrostenotic, symptomatic esophagus can potentially be avoided with optimal medical and elimination diet therapies. The molecular mechanisms underlying EoE pathogenesis are being unraveled, from which targeted therapies can be developed and evaluated in preclinical and clinical studies. Current clinical research efforts focus on optimization of topical corticosteroid delivery, dosing, frequency, and duration of treatment, either alone or in combination with tailored elimination diet. Preliminary clinical trials with biologics targeting interleukin (IL)-5 and IL-13/IL-4 have been completed.

CONCLUSION

Topical corticosteroid, elimination diet, and dilation are the current treatment modalities for confirmed EoE. The use of proton-pump inhibitors (PPI) is being suggested as a potential regimen to treat EoE, based on evolving understanding of PPI-responsive esophageal eosinophilia (PPI-REE). The complexity of EoE treatment regimens and frequent follow-ups require a multimodal, multi-disciplinary management approach to optimize patient care.

Treatment of eosinophilic esophagitis in the pediatric patient: an evidence-based approach

Eosinophilic esophagitis (EoE) is a unique form of non-IgE-mediated food allergy characterized by esophageal eosinophilic infiltration that commonly causes dysphagia and food impaction in children and adolescents. Assessing the efficacy of dietary restrictions or drug therapies to achieve clinical and histologic resolution of EoE through randomized controlled trials and meta-analyses has resulted in new evidence-based guidelines. Avoiding food triggers is the only therapy targeting the cause of the disease. None of the currently available food allergy tests adequately predict food triggers for EoE. Exclusively feeding with an amino acid-based elemental diet and empiric six-food elimination diet (avoiding the six foods most commonly related with food allergy) has consistently provided the best cure rates, but their high level of restriction and need for multiple endoscopies are deterrents for implementation. Simpler and less restrictive empirical methods, like a four-food (milk, gluten-containing cereals, egg, legumes) or a two-food (milk and gluten) elimination diet, show encouraging results. Proton pump inhibitors are currently a first-line treatment, achieving histological remission and improvement of symptoms in 54.1 and 64.9% of pediatric EoE patients, respectively. The efficacy of topical corticosteroids in EoE assessed in several trials and summarized in meta-analyses indicates that budesonide and fluticasone propionate are significantly superior to placebos, both in decreasing eosinophil mucosal infiltration and in relieving symptoms. Owing to differences in drug delivery, viscous budesonide formulas seem to be the best pharmacological therapy for EoE.

CONCLUSION

Applying evidence-based therapies and a practical management algorithm provide an effective control of EoE. What is Known: • Eosinophilic esophagitis (EoE) now constitutes the main cause of dysphagia and food impaction in children, adolescents, and young adults. • Its chronic course and frequent progression to subepithelial fibrosis leading to strictures and narrow-caliber esophagus indicate the need for treatment. What is New: • Therapeutic goals in children with EoE include resolution of esophageal symptoms, to cure esophageal inflammation (mucosal healing) and restore a proper esophageal caliber in case of fibrostenotic endoscopic findings. Avoiding iatrogenic drug effects and nutritional deficiencies, as well as maintaining an adequate quality of life, is also essential. • Novel evidence-based guidelines, endorsed by several European scientific societies, incorporate recent advances in knowledge from several randomized controlled trials and systematic reviews to provide the best standard of care to pediatric patients, by following simple management algorithms.

The Role of Proton Pump Inhibitors in the Management of Pediatric Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic, local, immune-mediated disorder characterized by symptoms of esophageal dysfunction and the presence of a dense eosinophilic infiltrate in the esophageal mucosa. Consensus diagnostic recommendations for EoE diagnosis included absence of histological response to a proton-pump inhibitor (PPI) trial, to exclude gastro-oesophageal reflux disease (GERD)-associated esophagitis. This recommendation exposed an entity known as "proton pump inhibitor-responsive esophageal eosinophilia" (PPI-REE), which refers to patients with EoE phenotype who are PPI-responsive and do not present GERD. In recent years, there is evidence which indicates that PPI-REE is a sub-phenotype of EoE with similar clinical, endoscopic, histological and genetic characteristics, as well as Th2-related inflammatory response. As a result, PPIs should be considered another treatment for EoE and not a diagnostic tool. PPI-REE was originally described in a case series which included two children and in two retrospective pediatric series. Later, a prospective pediatric study showed a high rate of response to PPIs at high doses with long-term maintenance at lower doses. PPI monotherapy in children with esophageal eosinophilia (EE) has been observed to reduce eotaxin-3 expression in epithelial cells and to practically reverse the allergy and inflammatory transcriptome. These data reveal that PPIs are also an effective treatment for EoE in pediatric patients, although more studies are necessary in order to define the best induction and maintenance treatment regimen, the long-term safety profile and their influence on the occurrence of fibrosis and esophageal remodeling.

Current concepts in eosinophilic esophagitis

Background

Eosinophilic esophagitis (EoE) is a disease entity first described in the 1990s, but showing an increasing incidence that is characterized clinically by esophageal dysfunction and histologically by a striking eosinophil infiltration.

Methods

This article discusses new aspects of the pathogenesis, symptoms, diagnosis, and treatment of EoE.

Results

EoE affects both children and adults and is frequently associated with atopic disease and IgE sensitization. Barrier dysfunction and T‑helper 2 inflammation are considered to be pathogenetically important factors. Recently, a proton pump inhibitor (PPI)-sensitive EoE subtype as well as an EoE-like disorder have been described.

Conclusion

Research in recent years has contributed to a better understanding of the disease spectrum and pathogenesis of EoE, including genetic dispositions, thereby laying the foundation for innovative treatment approaches.

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.

Montelukast Does not Maintain Symptom Remission After Topical Steroid Therapy for Eosinophilic Esophagitis

BACKGROUND & AIMS

Montelukast, a cysteinyl leukotriene type-1 receptor blocker, has been shown in small retrospective studies to reduce symptoms in patients with eosinophilic esophagitis (EoE). We performed a randomized, placebo-controlled, double-blind trial to determine whether montelukast maintains symptomatic remission induced by topical steroid therapy in patients with EoE.

METHODS

We performed a prospective study of adult patients with EoE (solid-food dysphagia and a peak esophageal eosinophil count of >20 cells/high-powered field) enrolled at the Mayo Clinic in Rochester, Minnesota, from April 2008 through February 2015. All patients had been treated previously for at least 6 weeks with a topical steroid until their symptoms were in remission. Steroids were discontinued and patients then were assigned randomly to groups given montelukast (20 mg/day, n = 20) or placebo (n = 21) for 26 weeks (groups were matched for age, sex, history of allergic disease, reflux symptoms, and endoscopic findings of EoE). Study participants were assessed via a structured telephone interview at weeks 2, 4, 8, 12, 16, 20, and 24. Remission was defined as the absence of solid-food dysphagia.

RESULTS

Based on an intention-to-treat analysis, after 26 weeks, 40.0% of subjects in the montelukast group and 23.8% in the placebo group were in remission. The odds ratio for remission in the montelukast group was 0.48 (95% confidence interval, 0.10-2.16) (P = .33). No side effects were reported from either group.

CONCLUSIONS

In a randomized controlled trial of the ability of montelukast to maintain remission in patients in remission from EoE after steroid therapy, we found montelukast to be well tolerated; 40% of patients remained in remission, but this proportion did not differ significantly from that of the placebo group. ClinicalTrials.gov no: NCT00511316.

Absence of esophageal eosinophilia in a toddler with severe eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a clinicopathologic disease characterised by esophageal dysfunction and eosinophil-predominant inflammation. Diagnosing EoE in children is particularly challenging as they tend to present with nonspecific symptoms and their mucosal specimens may have less than the threshold number of eosinophils. Reluctance to subject children to multiple endoscopic procedures and anesthesia often results in treatment with a proton pump inhibitor (PPI) first to evaluate clinical response. This approach presents a problem as a diagnosis of EoE may be missed. Here we present a case of a child with severe EoE whose initial biopsy did not show esophageal eosinophilia but progressed on to advance dis ease despite clinical response to PPI therapy.

Eosinophilic disorders of the gastro-intestinal tract: an update

Eosinophilic diseases of the gastrointestinal tract, including eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE), are rare chronic pathologies of the digestive system, with an immuno-mediated pathogenesis. Recent data suggest that, together with the “classic” IgE-response to allergens, also a delayed hypersensitivity mechanism could be involved in the development of eosinophilic disorders. EoE and EGE were studied only in the latest decades and as a consequence accurate data are not yet available, concerning not only pathogenesis, but also epidemiology, treatment and outcomes. The diagnosis of EoE is centered on endoscopic findings but the certainty is obtained by histological examination from biopsy samples, that has a sensitivity of 100% when based on five samples. The currently available treatments include topical corticosteroids, specific diets and endoscopic treatment. Concerning EGE, three subtypes (mucosal, muscular, and serosal) were identified. The diagnosis is based, as for EoE, on endoscopic and histological assessment, and the treatment includes pharmacological and dietetic approaches. Further studies are warranted in order to better define the etiology and pathogenesis of eosinophilic diseases of the gastrointestinal tract, and thus to develop more appropriate and specific therapies.

Strategies for Medical Management of Pediatric Eosinophilic Esophagitis

OBJECTIVE

Eosinophilic esophagitis (EoE) is associated with significant morbidity in children. Strategies for optimizing its outcomes are hence essential. We aimed to review the strategies for medical management of EoE in children.

METHODS

We conducted a systematic review of randomized controlled trials (RCTs) of medical interventions in children with EoE, using the Cochrane methodology. Databases including PubMed, EMBASE, CINAHL, Cochrane Central Library, and Google scholar were searched up to March 2016. Primary outcomes included histological (peak eosinophil count) and symptomatic remission. Secondary outcomes were improvement in endoscopic and other histological parameters and adverse effects.

RESULTS

A total of 5 RCTs (N = 448) with low to unclear risk of bias were included. The interventions included topical oral steroids, swallowed enteral steroids and anti- interleukin (IL)5 agent. Pooling of data from all trials was not possible owing to significant heterogeneity in interventions. Meta-analysis of data (N = 141) from 3 RCTs (oral viscous budesonide: 2, fluticasone: 1) showed significant histological remission in the intervention versus control group participants (risk difference: 10.32 [95% confidence interval: 3.04, 35.03]; P = 0.0002), level of evidence-low. Compared with anti-IL5 agent, the trials assessing steroids reported high rates of clinical remission. Clinical remission did not correlate with histological improvement in any trial. Except for systemic corticosteroids, there were no significant adverse effects related to other interventions.

CONCLUSIONS

Limited low-quality evidence exists on the effects of various interventions in children with EoE. The beneficial effects of swallowed steroid need to be confirmed in large well-designed RCTs.

Clinicopathologic Analysis of Proton Pump Inhibitor-Responsive Esophageal Eosinophilia in Korean Patients

BACKGROUND/AIMS

Proton pump inhibitor-responsive esophageal eosinophilia (PPI-REE) is a newly recognized form of eosinophilic esophagitis (EoE) that responds to PPI therapy. It remains unclear whether PPI-REE represents a subphenotype of gastroesophageal reflux disease, a subphenotype of EoE, or its own distinct entity. The aim was to evaluate the clinicopathologic features of PPI-REE.

METHODS

Six patients were diagnosed with PPI-REE based on symptoms, endoscopic abnormalities, esophageal eosinophilia with ≥15 eosinophils/high-power field, and a response to PPI treatment. Symptoms and endoscopic and pathological findings were evaluated.

RESULTS

The median follow-up duration was 12 months. Presenting symptoms included dysphagia, heartburn, chest pain, foreign body sensation, acid reflux, and sore throat. All patients had typical endoscopic findings of EoE such as esophageal rings, linear furrows, nodularity, and whitish plaques. Three patients had a concomitant allergic disorder, and one had reflux esophagitis. Four patients exhibited elevated serum IgE, and five had positive skin prick tests. All patients experienced symptomatic resolution within 4 weeks and histologic resolution within 8 weeks after starting PPI therapy. There was no symptomatic recurrence.

CONCLUSIONS

PPI therapy induced rapid resolution of symptoms and eosinophil counts in patients with PPI-REE. Large-scale studies with long-term follow-up are warranted.

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.

Pharmacological treatment of eosinophilic gastrointestinal disorders

INTRODUCTION

Eosinophilic gastrointestinal disorders (EGIDs) are increasingly prevalent chronic inflammatory diseases characterized by eosinophilic infiltration of the gastrointestinal (GI) tract, in the absence of other known causes of eosinophilia.

AREAS COVERED

Clinical management of EGIDs is challenging, as there are currently limited therapeutic options available. The most common EGID is eosinophilic esophagitis (EoE), and rarer forms are eosinophilic gastritis, eosinophilic gastroenteritis, and eosinophilic colitis. Clinical presentation depends on the affected GI site. Recently duodenal eosinophilia has been recognized to commonly be present in patients with functional dyspepsia. This review will provide an overview of the pathogenesis and therapeutic management of EGIDs, with particular focus on the pharmacological strategies for these conditions. Expert commentary: Despite the considerable progress made in understanding the pathogenesis of EGIDs, there is still an urgent need for the development of specific and effective therapeutic approaches. Therapeutic management protocols are required that are based on rigorous clinical investigation in large prospective controlled trials to better understand the risks, benefits and limitations of each therapy. More well-defined and consistent end-points are also required to assess treatment outcomes, as there has been variability between patient reported outcomes, clinical outcomes, and histological outcomes in the studies to date.

Case report of proton pump inhibitor responsive esophageal eosinophilia: why 2 months of proton pump inhibitors is required

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease defined by the 2nd EoE consensus panel as: 'symptoms related to esophageal dysfunction, ≥15 eosinophils per high-power field, eosinophilia that persists after a trial of proton pump inhibitor (PPI) therapy, and exclusion of other secondary causes of esophageal eosinophilia'. After Ngo et al. first reported a case series of 3 patients initially diagnosed with eosinophilic esophagitis responding endoscopically and histologically to PPI therapy, the term PPI-responsive esophageal eosinophilia has evolved. Several studies have since confirmed the existence of this entity. Although recent ACG guidelines call for a 2-month course of PPI followed by endoscopy biopsies this recommendation is classified as a strong recommendation with 'low evidence', and has not been proven in the literature. We present a case of PPI-REE treated with rabeprazole 20 mg BID for 2 months, and describe simultaneous symptom resolution with histological and endoscopic remission of disease. This unique case with serial endoscopy and histology at baseline and monthly suggests the current recommendation of at least two months therapy with PPIs dosed twice daily is appropriate. Future studies will need to address duration of high dose therapy, whether patients can be stepped down to once a day PPI, and therapeutic strategy for transient responders.

The Immunologic Mechanisms of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic allergic inflammatory disease that is triggered by food and/or environmental allergens and is characterized by a clinical and pathologic phenotype of progressive esophageal dysfunction due to tissue inflammation and fibrosis. EoE is suspected in patients with painful swallowing, among other symptoms, and is diagnosed by the presence of 15 or more eosinophils per high-power field in one or more of at least four esophageal biopsy specimens. The prevalence of EoE is increasing and has now reached rates similar to those of other chronic gastrointestinal disorders such as Crohn's disease. In recent years, our understanding of the immunologic mechanisms underlying this condition has grown considerably. Thanks to new genetic, molecular, cellular, animal, and translational studies, we can now postulate a detailed pathway by which exposure to allergens results in a complex and coordinated type 2 inflammatory cascade that, if not intervened upon, can result in pain on swallowing, esophageal strictures, and food impaction. Here, we review the most recent research in this field to synthesize and summarize our current understanding of this complex and important disease.

High Prevalence of Response to Proton-pump Inhibitor Treatment in Children With Esophageal Eosinophilia

OBJECTIVES

Proton-pump inhibitor-responsive esophageal eosinophilia is a newly recognized entity with an unclear prevalence in children, as only retrospective data are available. The aim of this study was to determine the prevalence and clinical features of proton-pump inhibitor-responsive esophageal eosinophilia in children.

METHODS

This prospective study enrolled patients with esophageal symptoms and esophageal eosinophilic counts as 15 or more than 15 eos/hpf (eosinophils per high-power field). Children received treatment with esomeprazole 1 mg · kg per dose twice daily for 8 weeks and the endoscopy was repeated. Complete response to proton-pump inhibitor (PPI) was defined as 5 or less than 5 eos/hpf, and a partial response as >5 and <15 eos/hpf in post-treatment biopsies.

RESULTS

Fifty-one children (74.5% boys) were included. Histological response was observed in 35 children (68.6%): 24 children (47%) had a complete response and 11 children (21.6%) had a partial response. Only 16 children (31.4%) were diagnosed with eosinophilic esophagitis (EoE). There were no differences in history of atopy, allergy tests, pH study results, and endoscopic scores. Clinical symptoms were similar, with the exception of food impaction, which was more frequent in children with EoE (56.2% vs 20%, P = 0.01). The mean pretreatment peak eosinophil count was higher in patients with EoE (74.8 ± 36.2 vs 46.3 ± 30.7, P = 0.007). Eleven of the 14 patients (78.6%) on a lower PPI treatment maintenance dose remained in clinicopathologic remission at 1-year follow-up.

CONCLUSIONS

A significant proportion of children with esophageal eosinophilia responded to high dose PPI treatment. Clinical, endoscopic, and pH study results were similar, with exception of patients with EoE, who were more likely to experience food impaction and have higher esophageal eosinophil counts.

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.

Mechanisms of Disease of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a recently recognized inflammatory disease of the esophagus with clinical symptoms derived from esophageal dysfunction. The etiology of EoE is now being elucidated, and food hypersensitivity is emerging as the central cornerstone of disease pathogenesis. Herein, we present a thorough picture of the current clinical, pathologic, and molecular understanding of the disease with a focus on disease mechanisms.

The efficacy of step-down therapy in adult patients with proton pump inhibitor-responsive oesophageal eosinophilia

BACKGROUND

Proton pump inhibitor-responsive oesophageal eosinophilia (PPI-REE) is common in patients with suspected eosinophilic oesophagitis (EoE). However, the long-term efficacy of PPIs and the best maintenance doses are yet to be defined.

AIM

To evaluate the durability of the response to PPI therapy after tapering PPI doses in PPI-REE patients.

METHODS

Prospective study conducted on PPI-REE patients. Upon complete remission on high-dose PPI therapy (omeprazole 40 mg b.d. for 8 weeks), PPI doses were tapered followed by an endoscopic procedure after each dose reduction. The primary outcomes were sustained clinical and histological remission (<15 eos/HPF) after decreasing PPI doses.

RESULTS

From a total of 121 patients with suspected EoE, 40 (33%) achieved complete remission on high-dose PPIs and were given a diagnosis of PPI-REE. No patient in histological remission showed symptom relapse, but half of patients with relapsing oesophageal inflammation were in clinical remission. After reduction to omeprazole 40 mg once daily, 38/31 (81%) remained in complete remission. Among these latter patients, 15/18 (83%) were kept in remission with omeprazole 20 mg once daily. As for side effects, only asymptomatic hypertransaminasemia and oesophageal candidiasis were observed in two patients while receiving high doses of omeprazole.

CONCLUSIONS

Most PPI-responsive oesophageal eosinophilia patients show sustained clinical and histological remission with daily PPI doses equal to or below 40 mg of omeprazole. As adverse effects only appeared with the highest dose of omeprazole, it would be advisable to individualise the dose of PPIs for each patient, lowering it to the minimum capable of maintaining the disease controlled.

Current Management of Eosinophilic Esophagitis 2015

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition characterized by esophageal dysfunction and eosinophilic infiltrate (≥15/hpf) in the esophageal epithelium and the absence of other potential causes of eosinophilia. The prevalence is increasing and is the most common cause of solid food dysphagia in children and young adults. This article will review the diagnosis and management of EoE based on consensus conferences, systematic reviews, and meta-analysis and highlights seminal studies in our evolving treatment of this disease. However, all answers are not available and I will remark about the lessons learned in my clinical practice seeing EoE patients over the last 25 years. The complicated etiology of the complaint of dysphagia in EoE patients will be reviewed. The importance of utilizing endoscopy, biopsies, and barium esophagram to help define the 2 phenotypes (inflammatory, fibrostenosis) of EoE will be highlighted. The controversy about PPI-responsive esophageal eosinophilia will be discussed and contrasted with idiopathic EoE. Finally, the 3 treatment options for EoE (drugs, diet, dilation) will be reviewed in detail and a useful clinical management algorithm presented.

Efficacy of Proton Pump Inhibitor Drugs for Inducing Clinical and Histologic Remission in Patients With Symptomatic Esophageal Eosinophilia: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Proton pump inhibitor (PPI) therapy might lead to clinical and histologic remission in a significant proportion of patients with symptomatic esophageal eosinophilia (>15 eos/high-power field). We aimed to evaluate systematically the efficacy of PPI therapy for these patients.

METHODS

A search in MEDLINE, EMBASE, and SCOPUS databases, and the American Gastroenterological Association Institute, American College of Gastroenterology, and United European Gastroenterology meetings abstract books, was performed. Primary outcomes were clinical response and histologic remission (<15 eos/high-power field) after PPI therapy. Secondary outcomes were the influence on the response to PPIs of age group, study design/quality, PPI type, doses and interval dosing, and pH monitoring results. Data were pooled using a random-effects model.

RESULTS

Thirty-three studies (11 prospective studies) comprising 619 patients with symptomatic esophageal eosinophilia (188 children and 431 adults) were included. PPI therapy led to a clinical response in 60.8% (95% confidence interval, 48.38%-72.2%; I(2) = 80.2) and histologic remission in 50.5% (95% confidence interval, 42.2%-58.7%; I(2) = 67.5) of patients. No differences were observed regarding the study population (children vs adults), the type of publication, or its quality. PPIs were nonsignificantly more effective in prospective studies (52.6% vs 39.1%) administered twice daily compared with once daily (55.9% vs 49.7%), and with pathologic pH monitoring (65.4% vs 49.3%). A significant publication bias in favor of studies reporting histologic responses to PPIs was observed.

CONCLUSIONS

PPI therapy induces clinicohistologic remission in half of patients with symptomatic esophageal eosinophilia. This finding should be interpreted with caution because of poor-quality evidence, heterogeneity, and publication bias.

Long-term assessment of esophageal remodeling in patients with pediatric eosinophilic esophagitis treated with topical corticosteroids

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic TH2 inflammatory disease characterized by tissue remodeling that leads to esophageal strictures and food impactions. Effects of therapy on long-term remodeling in patients with pediatric eosinophil-associated diseases have not been previously described.

OBJECTIVE

We sought to understand the long-term control of esophageal remodeling in patients with EoE.

METHODS

We assessed endoscopic and histologic remodeling and TGF-β1 expression in esophageal biopsy specimens from children (n = 32) with EoE treated with topical corticosteroids (TCSs) over 10 years (mean, 4.5 years). We used standardized EoE scoring tools to gauge endoscopic and symptom features.

RESULTS

Seven hundred thirty-eight biopsy specimens from 246 endoscopic procedures were evaluated over 10 years. Four hundred eighty-six biopsy specimens had adequate lamina propria for evaluation of subepithelial remodeling. The severity of epithelial esophageal eosinophilia correlated with epithelial remodeling (basal zone hyperplasia, desquamation, and dilated intercellular spaces; P < .0001), lamina propria eosinophilia (P < .0001), and fibrosis (P < .0001). Sixteen subjects were initial responders (<15 eosinophils/high-power field) to TCSs. Responders and nonresponders spent 54% and 97% of their total disease duration with active EoE (P < .001) and 23% and 53% (P < .02) with maximal fibrosis scores, respectively. Responders had lower endoscopy scores during their disease duration (P = .013). Having less than 15 eosinophils/high-power field at any time correlated with lower fibrosis and endoscopic severity. TGF-β1(+) cell counts decreased in responders at the first biopsy, but this was not sustained. Symptoms did not correlate with other disease features.

CONCLUSIONS

Children with EoE have substantial esophageal remodeling, which associates with inflammation and can improve in a sustainable manner with TCSs. Although endoscopic features correspond to histologic features, symptoms did not correlate with inflammation or fibrosis.

Long-Term Loss of Response in Proton Pump Inhibitor-Responsive Esophageal Eosinophilia Is Uncommon and Influenced by CYP2C19 Genotype and Rhinoconjunctivitis

OBJECTIVES

Proton pump inhibitor-responsive esophageal eosinophilia (PPI-REE) is diagnosed in at least one-third of patients with suspected eosinophilic esophagitis (EoE). We aimed to evaluate the durability and factors influencing long-term efficacy of PPI therapy.

METHODS

Retrospective multicenter cohort study of patients with PPI-REE who had at least 12 months of follow-up. PPI therapy was tapered to the lowest dose, which maintained clinical remission. Primary outcomes were the proportion of patients with loss of histological response (<15 eos/HPF) and predictors of loss of response. CYP2C19 polymorphisms were determined from blood samples in a subset of patients.

RESULTS

Seventy-five PPI-REE patients were included (mean follow-up 26 months (12-85)), of whom fifty-five (73%) had sustained histological remission on low-dose PPI therapy. Loss of response was significantly higher in those patients with a CYP2C19 rapid metabolizer genotype (36% vs. 6%, P = 0.01) and with rhinoconjunctivitis (40% vs. 13%, P = 0.007). On the multivariate analysis, a CYP2C19 rapid metabolizer genotype (odds ratio (OR) 12.5; 95% confidence interval (CI): 1.3-115.9) and rhinoconjunctivitis (OR 8.6; 95% CI: 1.5-48.7) were independent predictors of loss of response. Among relapsing patients, eosinophilia was limited to the distal esophagus in 14/20 (70%). Nine of ten relapsers, with distal eosinophilia, all showing a CYP2C19 rapid metabolizer genotype, regained histological remission after PPI dose intensification.

CONCLUSIONS

Most PPI-REE patients remain in long-term remission on low-dose PPI therapy. CYP2C19 rapid metabolizer genotypes and rhinoconjunctivitis were independent predictors of loss of response to PPI, but patients frequently responded to PPI dose escalation.

Diagnostic approach to eosinophilic oesophagitis: Pearls and pitfalls

Eosinophilic oesophagitis (EoE) has first been described a little over 20 years ago. EoE has been defined by a panel of international experts as a "chronic, immune/antigen-mediated, oesophageal disease, characterized clinically by symptoms related to oesophageal dysfunction and histologically by eosinophil-predominant inflammation". A value of ≥ 15 eosinophils has been defined as histologic diagnostic cutoff. Other conditions associated with oesophageal eosinophilia, such as gastro-oesophageal reflux disease (GERD), PPI-responsive oesophageal eosinophilia, or Crohn's disease should be excluded before EoE can be diagnosed. This review highlights the latest insights regarding the diagnosis and differential diagnosis of EoE.

Management of proton pump inhibitor responsive-esophageal eosinophilia and eosinophilic esophagitis: controversies in treatment approaches

Eosinophilic esophagitis (EoE) is a chronic immune-mediated clinicopathologic disease. The prevalence of EoE is approximately 1/2000 persons, EoE is now the most common cause of food impactions, with healthcare expenditures approaching US$ 1 billion annually. This article will discuss challenges related to proton pump inhibitor responsive esophageal eosinophilia, including distinguishing this condition from EoE and understanding the mechanisms behind the PPI response. For EoE, we will review multiple ongoing debates about treatment and monitoring strategies, including selecting treatment outcomes, optimizing medication formulations, approaching the steroid-refractory patient, conducting dietary elimination, prescribing long-term maintenance therapy and performing esophageal dilation.

Distinguishing GERD from eosinophilic oesophagitis: concepts and controversies

Over the past three decades, the detection of oesophageal mucosal eosinophils has transitioned from a biomarker of GERD to a diagnostic criterion for eosinophilic oesophagitis (EoE). In GERD, oesophageal eosinophils are considered part of the chronic inflammatory response to acid reflux, whereas the marked eosinophilia in EoE is viewed as a central feature of the immune response to ingested food and/or environmental antigen stimulation. Descriptions of a considerable subset of patients with symptomatic, endoscopic and histological findings of EoE that resolve with PPI therapy has led to confusion and controversy regarding the distinction of EoE from GERD. Study findings indicate that PPI-responsive oesophageal eosinophilia (PPI-REE) more closely resembles EoE than GERD, both from a clinical and immunological aspect. Although responsiveness to PPI therapy should not be utilized to exclude EoE, PPI therapy is effective at reducing oesophageal eosinophilia in ∼40% of patients, and PPI therapy is both a safe and practical initial step in the management of patients with oesophageal eosinophilia. Ongoing studies elucidating the mechanism behind PPI-REE will improve our understanding and management of EoE. In this Review, the mechanisms and evidence that underlie the controversy in the distinction between GERD and EoE are evaluated.

Proton pump inhibitor-responsive oesophageal eosinophilia and eosinophilic oesophagitis: more similarities than differences

PURPOSE OF REVIEW

The purpose of this study is to discuss the clinical, endoscopic and histologic features, pathogenesis and disease mechanisms of proton pump inhibitor (PPI)-responsive oesophageal eosinophilia (PPI-REE), and to highlight similarities and differences with eosinophilic oesophagitis (EoE).

RECENT FINDINGS

PPI-REE is a condition in which patients have clinical and histologic findings similar to EoE, but achieve complete remission with PPI treatment. More than one-third of patients who have oesophageal symptoms associated with oesophageal eosinophilia respond to PPI treatment. Emerging data elucidating the pathogenesis of PPI-REE have shown that Th2-related inflammatory factors such as interleukin (IL)-13, IL-5, eotaxin-3 and major basic protein (MBP) are elevated in PPI-REE, similar to EoE. PPI-REE also shares a genetic expression signature with EoE that reverses with PPI treatment. Mechanisms proposed to explain the PPI response include an acid-independent, anti-inflammatory action of PPIs and PPI-induced restoration of oesophageal barrier function.

SUMMARY

Multiple features of PPI-REE overlap extensively with EoE. This raises the question of whether PPI-REE is merely a subtype of EoE rather than an independent condition. This similarity may have future implications for algorithms informing evaluation and treatment of oesophageal eosinophilia.

IgE Antibody Detection and Component Analysis in Patients with Eosinophilic Esophagitis

BACKGROUND

Although IgE antibodies to cow's milk and wheat are common in patients with eosinophilic esophagitis (EoE), titers are low and responses to diet are not dependent on having IgE antibodies.

OBJECTIVE

To better define specific IgE antibody responses to foods, focusing on those foods that appear to play a role in EoE.

METHODS

Adult (n = 46) and pediatric (n = 51) patients with EoE were recruited for skin prick testing and serum measurement (whole and diluted) of IgE antibodies specific for aeroallergens, food extracts, and component allergens by ImmunoCAP. Immuno Solid-phase Allergen Chip analysis was also used to measure the specificity of IgE antibodies to 112 allergen molecules.

RESULTS

In adults and children, there was a higher prevalence of sensitization to food extracts by ImmunoCAP than by skin prick testing. Using Immuno Solid-phase Allergen Chip to assess the specificity of IgE antibodies to 112 allergen molecules, we found that results for food allergens were mostly negative. In contrast, ImmunoCAP assays for specific milk allergens gave positive IgE antibody results in 31 of 34 sera. The correlations between specific IgE antibody to Bos d 4 or Bos d 5 and milk extract were strong (R = 0.89 and 0.76, respectively; P < .001). The evidence that IgE antibodies to foods were directed at minor components of the extracts was further supported by measurements on diluted sera.

CONCLUSIONS

The IgE responses in cow's milk-sensitized patients with EoE are frequently to whey proteins Bos d 4 and Bos d 5, minor components of the extract. These IgE assays may be able to identify the proteins that are relevant to EoE even though IgE is not the primary mechanism.

PPI-responsive esophageal eosinophilia cannot be distinguished from eosinophilic esophagitis by endoscopic signs

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic antigen-mediated disease histologically characterized by eosinophil-predominant inflammation. One-third of patients respond to proton pump inhibitor (PPI) treatment; this group is identified as having PPI-responsive esophageal eosinophilia (PPI-REE). If we could predict the response to PPIs on the basis of endoscopic signs, futile treatment efforts and additional endoscopies to assess treatment response can be prevented.

OBJECTIVE

To determine whether endoscopic signs can distinguish PPI-REE from EoE.

METHODS

Endoscopic images of 30 EoE and 30 PPI-REE patients were included. Baseline characteristics were compared between groups. Complete clinical remission after a PPI trial for at least 8 weeks was classified as PPI-REE. Per patient, at least three depersonalized images were incorporated into a slideshow. These images were scored by two experienced endoscopists according to a validated classification system.

RESULTS

Characteristics were highly comparable between EoE and PPI-REE patients. Endoscopic signs were similar and did not enable differentiation between EoE and PPI-REE [presence of: rings (P=0.893), white exudates (P=0.209), furrows (P=0.371), edema (P=0.554), crepe paper esophagus (P=1.000), and strictures (P=0.071)].

CONCLUSION

Endoscopic signs at baseline endoscopy cannot distinguish EoE from PPI-REE before a PPI trial; the demographic and clinical characteristics in both groups are similar. Endoscopic features do not enable differentiation between PPI-REE and EoE.