Proton pump inhibitor-responsive esophageal eosinophilia does not preclude food-responsive eosinophilic esophagitis

Food elimination diet is a viable alternative therapy for eosinophilic esophagitis responsive to proton pump inhibitors

BACKGROUND

First-line treatment of eosinophilic esophagitis (EoE) includes monotherapy with proton-pump inhibitors (PPIs), food elimination diet (FED), or topical corticosteroids. Current guidelines suggest patients with EoE should continue any responsive first-line monotherapies. However, the efficacy of FED monotherapy in patients with EoE responsive to PPI monotherapy has not been well studied. Our study aimed to investigate how attempting FED monotherapy after experiencing remission of EoE after PPI monotherapy influenced long-term EoE management.

METHODS

We retrospectively identified patients with EoE responsive to PPI monotherapy who trialed FED monotherapy. We then employed a mixed method approach to a prospective cohort. Selected patients were observed long term for quantitative outcomes, while qualitative results were obtained from patient surveys regarding their perspectives on the trial of FED monotherapy.

RESULTS

We identified 22 patients who trialed FED monotherapy after experiencing remission of EoE following PPI monotherapy. Of these 22 patients, 13 had remission of EoE with FED monotherapy, while 9 had re-activation of EoE. Out of 22 patients, 15 were enrolled in a cohort for observation. No exacerbations of EoE occurred while on maintenance treatment. Most patients stated that they would recommend this process to others with EoE (93.33%) and that trial of FED monotherapy helped them identify a treatment plan that aligned with their lifestyle (80%).

CONCLUSION

Our work shows that FED monotherapy can be an effective alternative for patients with EoE responsive to PPI monotherapy that may improve patient quality of life, suggesting alternative treatment options should be considered for monotherapy-responsive EoE.

Long-Term Outcomes of the Six-Food Elimination Diet and Food Reintroduction in a Large Cohort of Adults With Eosinophilic Esophagitis

INTRODUCTION

Eosinophilic esophagitis (EoE) is an immune-mediated inflammatory condition with tissue eosinophilia resulting in esophageal dysfunction. The six-food elimination diet (SFED) is an EoE treatment approach that removes milk, wheat, soy, eggs, tree nuts/peanuts, and fish/shellfish. After histologic remission, food reintroduction occurs to identify a food trigger. Outcomes from large series of adults undergoing SFED and food reintroduction as clinical care are not known.

METHODS

A retrospective review (2006-2021) of adult patients with EoE from an academic center was completed. Patients were classified as full responders (<15 eos/hpf) after SFED. If reintroduction was pursued, food triggers identified were recorded.

RESULTS

Two hundred thirteen patients completed SFED. One hundred fifteen patients (54%) had response <15 eos/hpf after SFED. Seventy-seven percent of responders had symptom improvement. Thirty-two percent of initial nonresponders underwent repeat dietary elimination. Fifty-eight percent of patients (n = 123) achieved <15 eos/hpf after either initial or extended SFED. Seventy-eight percent of responders underwent food reintroduction. Sixty-nine percent had 1 food trigger identified, 24% had 2 allergens identified, and 4% had 3 allergens identified. The most common food triggers identified were milk, wheat, and soy.

DISCUSSION

This study describes the largest cohort reported of adult patients with EoE completing SFED with food reintroduction. The overall SFED histologic response was 54%, which increased to 58% with 1 additional round of dietary therapy, suggesting that 31% may respond in a second attempt. Most patients who completed food reintroduction had a single food trigger identified. Dietary elimination with specific food trigger identification is a feasible alternative to medical therapy for adults with EoE.

Drug treatment strategies for eosinophilic esophagitis in adults

INTRODUCTION

Eosinophilic esophagitis (EoE) is a clinical and pathological disorder, characterized by symptoms of esophageal dysfunction, and eosinophil-predominant inflammation restricted to the esophagus. Treatment outcomes include symptomatic remission, histological and endoscopic normalization and improving quality of life. Besides dietary modifications and endoscopic dilation, drugs available are swallowed topical corticosteroids (STCs) with reduced bioavailability and proton pump inhibitors (PPI).

AREAS COVERED

Herein, the authors review the current treatment strategies for EoE in adults, providing the reader with their expert perspectives. The authors give discussion to the value of PPIs as a first-line therapy for EoE, in addition to the use of STCs. The current development of new formulations of STCs targeting the esophagus and novel therapies aimed at blocking molecular pathways are also discussed. Finally, the authors briefly look at the value of monoclonal antibodies targeting IL-5RA, IL-13, IL-4 or Siglec8, and oral S1PR agonists to the treatment of EoE.

EXPERT OPINION

Viscose formulations of STC designed to coat the esophagus and new effervescent orodispersible tablets provide increased effectiveness at low doses. Investigational therapies that target several Th2-associated diseases seem useful in EoE. Comparative effectiveness and cost-utility analyses will help to position them in a complex therapeutic scenario.

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.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Food allergy and eosinophilic gastrointestinal disorders

Eosinophilic esophagitis (EoE) is a non-immunoglobulin E mediated disorder that has been seen with increasing frequency over the past 25 years. Although the presentation varies per age group from vomiting and refusal to eat in infants and toddlers to abdominal pain and dysphagia in school-aged children, and food impaction and indigestion in adolescents and adults. Treatment options include proton-pump inhibitors, dietary avoidance, swallowed steroids, or a combination of these. Newer therapies with biologics show promise in early studies. Cow's milk is the most common food trigger of EoE across all age groups, followed by wheat and eggs. Different dietary avoidance strategies have been used, and help from a knowledgeable nutritionist is often key to success. Patients with EoE commonly have other baseline atopic disease. Clinicians who take care of patients who are atopic, therefore, should have a higher index of suspicion for EoE in patients with dysphagia. The goals of treatment are both a decrease in symptoms and normalization of esophageal histology. Eosinophilic gastrointestinal diseases are less common and less likely to respond to dietary therapies and/or avoidance. Pathogenesis seems to be different and may be more autoimmune mediated. Trialing dietary restrictions is certainly an option in this cohort of patients. For persistent symptoms and abnormalities, systemic medications have been used, although biologics may be used in the future. Additional studies are needed to determine which patients will respond to which therapies.

Incidence and prevalence of eosinophilic oesophagitis increase continiously in adults and children in Central Spain: A 12-year population-based study

OBJECTIVES

To update population-based incidence, prevalence and trends for eosinophilic oesophagitis (EoE) in children and adults over the past decade.

METHODS

All patients referred to our EoE unit and living in the study area up to December 2017 were prospectively registered. Endoscopy and pathology databases and clinical charts were manually reviewed. Diagnosis of EoE was confirmed upon symptoms of oesophageal dysfunction and eosinophilia >15 eos/HPF. Annual incidence rates and prevalence were estimated with confidence intervals (CI) of 95%.

RESULTS

A total of 117 patients, including 19 children, were diagnosed with EoE in the 2006-2017 period. In 2017, the prevalence of EoE in children was 111.9 (95%CI, 67.4-174.6) cases/100,000 inhabitants and in adults 111.9 (95%CI, 90.8-136.5) also, and in both cases was significantly higher for male patients. The highest prevalences were observed in ages ranging between 20 and 24 and 35-39 years old. Mean incidence rates of the study period were 10.6 and 9.1 new cases/100,000 inhabitants/year in children and adults, respectively. Rise in the appearance of EoE during the study period exceeded that for endoscopic procedures. No seasonal variation was observed in the diagnosis of EoE.

CONCLUSION

The incidence and prevalence of EoE has increased sharply in central Spain, beyond previous estimations, with one out of every 893 inhabitants now being diagnosed.

Incidence and Prevalence of Pediatric Eosinophilic Esophagitis in Utah Based on a 5-Year Population-Based Study

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is often detected in children and is considered to be a rare disease, with prevalence values reported to be below 60 cases per 100,000 persons. To determine whether the incidence of EoE in children in Utah exceeds estimates from regional reports, we calculated incidence and prevalence values over a 5-year period.

METHODS

Using consensus guidelines for the diagnosis of EoE, we reviewed pathology records from the Intermountain Healthcare pathology database, from July 1, 2011 through June 31, 2016. We collected data on 10,619 pediatric patients with available esophageal biopsy results, and identified cases of esophageal eosinophilia (>14 eosinophils in a high-power microscopy field in an endoscopic biopsy). An EoE case required the presence of esophageal eosinophilia, symptoms of esophageal dysfunction, and the absence of co-morbid conditions that may cause esophageal eosinophilia. Annual pediatric EoE incidence and prevalence values were calculated per 100,000 children, based on averaged pediatric population estimates from census figures of Utah in 2010 and 2016.

RESULTS

We identified 1281 unique pediatric patients who met criteria for esophageal eosinophilia. Of those, 1060 patients met criteria for newly diagnosed EoE. Over the 5-year period studied, the average annual pediatric EoE incidence in Utah was 24 cases per 100,000 children. The prevalence in year 5 of the study was 118 cases per 100,000 children.

CONCLUSION

In a population-based study of children in Utah, we found the incidence and prevalence of pediatric EoE to be higher than previously reported. This could be due to the prominence of EoE risk factors in this region, as well as Utah's searchable medical record system that allows for reliable case ascertainment. Further studies of this type could increase disease awareness, prompting early referral to pediatric gastroenterologists and trials to strengthen evidence-based, algorithmic approaches to EoE diagnosis and treatment in children.

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.

Phenotypic Characterization of Eosinophilic Esophagitis in a Large Multicenter Patient Population from the Consortium for Food Allergy Research

BACKGROUND

Eosinophilic esophagitis (EoE) is increasingly common, but data on phenotypic aspects are still incomplete.

OBJECTIVES

To describe the clinical, endoscopic, and histopathologic features of a large number of children and adults with EoE across the United States.

METHODS

This was a multisite single visit registry enrolling subjects aged 6 months to 65 years with EoE. Participants provided responses regarding their medical history, with verification of the diagnosis and history by the study teams.

RESULTS

A total of 705 subjects were analyzed (median [interquartile range] age at enrollment 11.2 [6.7-17.7] years, 68.2% male, 87.9% whites). Of these, 67 subjects had concurrent gastrointestinal eosinophilia, with gastric mucosa most common. An age- and race-dependent time gap was present between symptom onset and time of diagnosis (adults and whites with longer gap). Food allergy and atopic dermatitis were associated with a decrease in this gap. Symptoms varied with age (more dysphagia and food impaction in adults) and with race (more vomiting in non-whites). Esophageal rings and strictures at diagnosis were more common in adults, although esophageal eosinophilia was comparable among age groups. Concomitant allergic disease (91%), infectious/immunologic disorders (44%), neurodevelopmental disorders (30%), and failure to thrive (21%) were common. Depression/anxiety increased with age. EoE was reported in 3% of parents and 4.5% of siblings.

CONCLUSIONS

Gastrointestinal eosinophilia is present in approximately 10% of patients with EoE; the symptom-diagnosis time gap is influenced by age, race, food allergy, and atopic dermatitis; symptoms vary with race; concurrent infectious/immunologic disorders and mental health disorders are common; and the level of esophageal eosinophils is comparable in patients with and without fibrostenotic features.

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.

PPI Trial for Eosinophilic Esophagitis: Chaos in the Community

INTRODUCTION

Despite consensus eosinophilic esophagitis (EoE) statement published in 2011 calling for a 2-month trial of protons pump inhibitor (PPI), the guidelines are not followed by many. We studied the practice patterns in our community and response to a PPI retrial in patients previously diagnosed with "idiopathic EoE."

METHODS

All patients presenting to the senior author's practice with suspected EoE from 2011 to 2015. Two cohorts were studied: (1) patients diagnosed in the community as "idiopathic EoE"; (2) treatment naïve patients given a PPI trial at University of South Florida. PPI responsive eosinophilia was defined after 2 months of high dose PPIs after initial diagnosis of mucosal eosinophilia and histologic response of <15 eosinophils per HPF. SPSS v19.0 was used to calculate mean difference and odds ratios (OR) and 95% confidence intervals.

RESULTS

In total, 78 patients met inclusion criteria, 46 patients had outside diagnosis of "idiopathic EoE," and 41 patients received a PPI trial at University of South Florida. In total, 34/46 (73.9%) community patients were placed on a PPI, 3/46 (6.5%) were placed on elimination diets, 31/46 (67.4%) steroids, and 21/46 (45.7%) were treated with both steroids/PPIs. Fewer patients received PPI trials in the community 3/46 (6.5%) versus 26/34 (76.5%) at our center [OR, 46.6 (95% CI, 11.3-191.5); P<0.0001]. In total, 12/26 (46.2%) were PPI responders on our retrial despite previously being diagnosed with idiopathic EoE. The group initially diagnosed at our center had a higher PPI response rate 12/15 (80%) versus 12/26 (46.2%) in the community group [OR, 7.58 (1.42, 40.55; P=0.018)].

CONCLUSIONS

The importance of a PPI trial is misunderstood and may be confused with the more traditional PPI trial for gastroesophageal reflux disease. This algorithm is critical and should be done before empiric steroids/diet therapies.

RNA sequencing confirms similarities between PPI-responsive oesophageal eosinophilia and eosinophilic oesophagitis

BACKGROUND

Although current American guidelines distinguish proton pump inhibitor-responsive oesophageal eosinophilia (PPI-REE) from eosinophilic oesophagitis (EoE), these entities are broadly similar. While two microarray studies showed that they have similar transcriptomes, more extensive RNA sequencing studies have not been done previously.

AIM

To determine whether RNA sequencing identifies genetic markers distinguishing PPI-REE from EoE.

METHODS

We retrospectively examined 13 PPI-REE and 14 EoE biopsies, matched for tissue eosinophil content, and 14 normal controls. Patients and controls were not PPI-treated at the time of biopsy. We did RNA sequencing on formalin-fixed, paraffin-embedded tissue, with differential expression confirmation by quantitative polymerase chain reaction (PCR). We validated the use of formalin-fixed, paraffin-embedded vs RNAlater-preserved tissue, and compared our formalin-fixed, paraffin-embedded EoE results to a prior EoE study.

RESULTS

By RNA sequencing, no genes were differentially expressed between the EoE and PPI-REE groups at the false discovery rate (FDR) ≤0.01 level. Compared to normal controls, 1996 genes were differentially expressed in the PPI-REE group and 1306 genes in the EoE group. By less stringent criteria, only MAPK8IP2 was differentially expressed between PPI-REE and EoE (FDR = 0.029, 2.2-fold less in EoE than in PPI-REE), with similar results by PCR. KCNJ2, which was differentially expressed in a prior study, was similar in the EoE and PPI-REE groups by both RNA sequencing and real-time PCR.

CONCLUSION

Eosinophilic oesophagitis and PPI-REE have comparable transcriptomes, confirming that they are part of the same disease continuum.

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.

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 maintenance therapy in eosinophilic esophagitis: who, why, and how?

In patients with eosinophilic esophagitis (EoE) who do not respond to proton pump inhibitors, initial anti-inflammatory/anti-eosinophilic treatment is with either topical corticosteroids or dietary elimination. A large body of literature supports the efficacy of these approaches, with histologic response rates in the 50-90% range for steroids and 70% range for the six-food elimination diet. However, these studies are almost all short-term and data evaluating long-term safety and efficacy of either treatment are limited. Nevertheless, because EoE is chronic, symptomatic, endoscopic, and histologic disease activity recurs when successful treatments are stopped. An emerging body of data also suggest that left untreated, persistent eosinophilic esophageal inflammation may progress to fibrostenosis over time. Therefore, maintenance therapy in EoE is intuitively attractive. This paper reviews the rationale for maintenance treatment in EoE, the available long-term pharmacologic and dietary response data for EoE, and discusses who may benefit the most from ongoing treatment. While all patients with EoE can be offered maintenance treatment, this option should be strongly recommended in patients with severe disease phenotypes or complications, including malnutrition or failure to thrive, esophageal fibrostenosis, strictures requiring dilation, recurrent food bolus impaction, history of perforation, and symptoms that recur quickly after treatment discontinuation. In all EoE patients, regular follow-up is also advised.

Future Directions in Eosinophilic Esophagitis

Eosinophilic esophagitis advances parallel the increased prevalence. Developments include refining the diagnostic criteria, identifying risk factors, appreciating the contribution of inflammatory pathways, recognizing the importance of subepithelial remodeling, validating trial endpoints, defining a role for biological therapies, and optimizing dietary therapy. Endoscopic outcomes have emerged as endpoints in trials of novel therapeutics. Expanding efforts seek to develop less-invasive methods to assess disease activity thereby reducing the burden of repeated endoscopic procedures during elimination diets. The functional lumen imaging probe is now identified as a determinant of complications with potential utility as a therapeutic endpoint.

A Review of Tertiary Referrals for Management of Pediatric Esophageal Eosinophilia

Background: Eosinophilic esophagitis is a chronic, immune-mediated disease characterized by symptoms of esophageal dysfunction and ≥15 eosinophils/high-powered field (eos/hpf). Proton pump inhibitor responsive esophageal eosinophilia (1) is an entity of esophageal eosinophilia that responds to PPI therapy and is thought to be clinically and histologically similar to EoE. Current guidelines suggest therapy with PPI prior to endoscopy and use of PPI as first line for esophageal eosinophilia. In order to gain a better understanding of community practice patterns and to try differentiate between these two entities, we sought to evaluate the clinical presentations, treatment and final diagnoses of patients presenting to our institution for second opinions of esophageal eosinophilia. Methods: A search of our electronic medical record yielded a list of patients presenting for a second opinion of esophageal eosinophilia. Charts were reviewed for clinical information. Results: A total of 187 charts were included. Patients ranged from 1-19 years old with 75% being male and 74% being Caucasian. Of the patients who had documentation of their medications at the time of initial endoscopy, 70% were not on any PPI prior to their endoscopy, and 94% were on <2 mg/kg/day. Of the 19 patients who had full response to PPI therapy and were diagnosed with PPI-REE, close to half had previously been treated with diet, steroids, or both. Patients with final diagnosis of EoE had significantly higher eos/hpf on initial endoscopy compared to those with diagnosis of PPI-REE (51.9 ± 30.6 v. 35.8 ± 16.4. p = 0.027), as well as higher likelihood of having IgE-mediated food allergy (79 v. 47%, p = 0.003). Conclusions: Diagnostic and therapeutic algorithms are needed for esophageal eosinophilia to prevent misdiagnosis and unnecessary procedures and therapies.

Eosinophilic Esophagitis: Pathophysiology and Definition

Eosinophilic esophagitis is an adaptive immune response to patient-specific antigens, mostly foods. Eosinophilic esophagitis is not solely IgE-mediated and is likely characterized by Th2 lymphocytes with an impaired esophageal barrier function. The key cytokines and chemokines are thymic stromal lymphopoeitin, interleukin-13, CCL26/eotaxin-3, and transforming growth factor-β, all involved in eosinophil recruitment and remodeling. Chronic food dysphagia and food impactions, the feared late complications, are related in part to dense subepithelial fibrosis, likely induced by interleukin-13 and transforming growth factor-β.

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.

The role of endoscopy in eosinophilic esophagitis: from diagnosis to therapy

Eosinophilic esophagitis (EoE) has arisen as a common disorder in current clinical and endoscopic gastroenterology practice. Areas covered: A comprehensive review of the literature to summarize and update different aspects related with the use of endoscopy in the diagnostic workout and treatment of pediatric and adult EoE patients is conducted. Expert commentary: Endoscopic features in EoE are frequently subtle, so were inadverted in some initial reports of the disease. Literature has described a wide number of EoE-associated features, systematized in the EREFS classification, which standardized the grade and severity of exudates, rings, edema, furrows, and strictures. The insufficient reliability of these features to predict eosinophilic inflammation still makes biopsies essential in diagnosing or monitoring EoE. EoE causes half of the food impactions requiring endoscopy; food impaction leads to EoE diagnosis in up to half of cases. Long term consequences of EoE include esophageal remodeling leading to strictures and narrowing, thus impairing symptoms and needs dilation. Recognizing the risks from dilation in EoE required carrying out a safe technique to avoid the high complication rate reported in the early literature. Endoscopic dilation should be considered in patients with esophageal narrowing and dysphagia/food impaction unresponsive to diet or drugs-based anti-inflammatory treatment.

Advances in mechanisms of allergic disease in 2016

This review highlights advances in mechanisms of allergic disease, particularly type 2 innate lymphoid cells; T_H2 lymphocytes; eicosanoid regulation of inflammation; extracellular vesicles in allergic responses; IL-33; microbiome properties, especially as they relate to mucosal barrier function; and a series of findings concerning the allergic inflammatory cells eosinophils, basophils, and mast cells. During the last year, mechanistic advances occurred in understanding type 2 innate lymphoid cells, particularly related to their response to ozone, involvement with experimental food allergy responses, and regulation by IL-33. Novel ways of regulating T_H2 cells through epigenetic regulation of GATA-3 through sirtuin-1, a class III histone deacetylase, were published. The understanding of eicosanoid regulation of inflammation increased and focused on additional properties of phospholipase A₂ and the role of prostaglandin D₂ and its receptors and inhibitory prostaglandin E₂ pathways. Mechanisms through which extracellular vesicles are released and contribute to allergic responses were reported. There was a deeper appreciation of mucosal barrier function, the epithelial alarmin IL-33, and the microbiome. Finally, there were advances concerning allergic inflammatory cells (mast cells, basophils, and eosinophils) that will undoubtedly have an effect on disease understanding and new therapeutic strategies.

Management of refractory eosinophilic oesophagitis

The goal of this Review is to discuss the clinical approach to patients who do not respond to treatment for eosinophilic oesophagitis (EoE). Refractory EoE is challenging to manage as there are limited data to guide decision-making. In this Review, refractory EoE is defined as persistent eosinophilia in the setting of incomplete resolution of the primary presenting symptoms and incomplete resolution of endoscopic findings following a PPI trial, and after treatment with either topical steroids or dietary elimination. However, this definition is controversial. This Review will examine these controversies, explore how frequently non-response is observed, and highlight potential explanations and predictors of non-response. Non-response is common and affects a large proportion of patients with EoE. It is important to systematically assess multiple possible causes of non-response, as well as consider treatment complications and an incorrect diagnosis of EoE. If non-response is confirmed, second-line treatments are required. Although the overall response rate for second-line therapy is disappointing, with only half of patients eventually responding, there are several promising agents that are currently under investigation, and the future is bright for new treatment modalities for refractory EoE.

White Paper AGA: Drug Development for Eosinophilic Esophagitis

Since first characterized in 2 small case series in the early 1990s, eosinophilic esophagitis (EoE) has emerged as a commonly identified cause of esophageal symptoms in children and adults.1,2 Although several highly effectively dietary, pharmacologic, and endoscopic therapies have been reported, none is currently approved by either the US Food and Drug Administration (FDA) or European regulatory authorities. Evolving diagnostic criteria have challenged drug development, in particular the recognition of complex interactions with the most prevalent esophageal disorder, gastroesophageal reflux disease (GERD). Heterogeneity in the clinical presentations of affected children and adults has created difficulties with uniform inclusion criteria and the development of disease-specific, patient-reported outcome (PRO) instruments. Furthermore, controversies regarding the appropriate therapeutic endpoints of EoE have impeded the design of clinical trials. Despite these obstacles, collaborative efforts by investigators, industry, the FDA, and patient advocacy groups have resulted in substantial progress in drug development in EoE over the past 2 decades.3 The purpose of this article is to summarize discussions on EoE based on the 2016 Drug Development Conference sponsored by the Center for Diagnostics and Therapeutics of the American Gastroenterological Association.

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.

Eosinophilic esophagitis: Update in diagnosis and management. Position paper by the Italian Society of Gastroenterology and Gastrointestinal Endoscopy (SIGE)

Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease of the esophagus characterized by symptoms related to esophageal dysfunction, as well as significant esophageal eosinophilia. The entity exists worldwide but has been most extensively studied in Western countries. However, a wide range of symptoms has been noticed such as chest pain or gastro-esophageal reflux disease-like symptoms. Upper gastro-intestinal endoscopy and esophageal biopsies are crucial for the diagnosis. Endoscopy might be normal or reveal typical patterns such as rings, furrows, exudates, edema, and stricture. Two to four biopsies should be performed both in the distal and in the proximal esophagus, and 15 eosinophils per high power field within the esophageal epithelium are the minimal threshold to diagnose eosinophilic esophagitis. Allergy testing is recommended, although its impact to orient treatment remains to be demonstrated. Eosinophilic esophagitis treatment includes medical treatment, diet and endoscopic dilation. Proton pump inhibitors are the first-line therapy as up to 50% of patients respond well to proton pump inhibitors irrespective of objective evidence of GERD. Topical viscous corticosteroids or elimination diet are the treatment of choice in case of unresponsiveness to proton pump inhibitors.

Eosinophilic esophagitis: current understanding and evolving concepts

Eosinophilic esophagitis (EoE) is now considered to represent a form of food allergy and this is demonstrated by a response to elimination diet in many patients. A critical additional factor may be an inherent impairment in epithelial barrier integrity, possibly worsened by reflux of gastric contents and improved with proton pump inhibitor (PPI) use. Key clinic challenges are posed by the absence of reliable allergy tests to guide elimination diet, and the subsequent need for invasive endoscopic assessment following empirical food challenge, meaning that corticosteroids will remain the mainstay of therapy for many. From a research standpoint, determining if impairments in barrier integrity are innate, and how PPIs address this deficit (which may be pH independent) are important questions that when answered may allow future therapeutic advancement.

Effective and safe proton pump inhibitor therapy in acid-related diseases - A position paper addressing benefits and potential harms of acid suppression

BACKGROUND

The introduction of proton pump inhibitors (PPIs) into clinical practice has revolutionized the management of acid-related diseases. Studies in primary care and emergency settings suggest that PPIs are frequently prescribed for inappropriate indications or for indications where their use offers little benefit. Inappropriate PPI use is a matter of great concern, especially in the elderly, who are often affected by multiple comorbidities and are taking multiple medications, and are thus at an increased risk of long-term PPI-related adverse outcomes as well as drug-to-drug interactions. Herein, we aim to review the current literature on PPI use and develop a position paper addressing the benefits and potential harms of acid suppression with the purpose of providing evidence-based guidelines on the appropriate use of these medications.

METHODS

The topics, identified by a Scientific Committee, were assigned to experts selected by three Italian Scientific Societies, who independently performed a systematic search of the relevant literature using Medline/PubMed, Embase, and the Cochrane databases. Search outputs were distilled, paying more attention to systematic reviews and meta-analyses (where available) representing the best evidence. The draft prepared on each topic was circulated amongst all the members of the Scientific Committee. Each expert then provided her/his input to the writing, suggesting changes and the inclusion of new material and/or additional relevant references. The global recommendations were then thoroughly discussed in a specific meeting, refined with regard to both content and wording, and approved to obtain a summary of current evidence.

RESULTS

Twenty-five years after their introduction into clinical practice, PPIs remain the mainstay of the treatment of acid-related diseases, where their use in gastroesophageal reflux disease, eosinophilic esophagitis, Helicobacter pylori infection, peptic ulcer disease and bleeding as well as, and Zollinger-Ellison syndrome is appropriate. Prevention of gastroduodenal mucosal lesions (and symptoms) in patients taking non-steroidal anti-inflammatory drugs (NSAIDs) or antiplatelet therapies and carrying gastrointestinal risk factors also represents an appropriate indication. On the contrary, steroid use does not need any gastroprotection, unless combined with NSAID therapy. In dyspeptic patients with persisting symptoms, despite successful H. pylori eradication, short-term PPI treatment could be attempted. Finally, addition of PPIs to pancreatic enzyme replacement therapy in patients with refractory steatorrhea may be worthwhile.

CONCLUSIONS

Overall, PPIs are irreplaceable drugs in the management of acid-related diseases. However, PPI treatment, as any kind of drug therapy, is not without risk of adverse effects. The overall benefits of therapy and improvement in quality of life significantly outweigh potential harms in most patients, but those without clear clinical indication are only exposed to the risks of PPI prescription. Adhering with evidence-based guidelines represents the only rational approach to effective and safe PPI therapy. Please see related Commentary: doi: 10.1186/s12916-016-0724-1 .

Eosinophilic esophagitis: What can we learn from Crohn's disease?

Eosinophilic esophagitis (EoE) is an emerging esophageal inflammatory disorder affecting children and young adults. As a relatively new disease, EoE is still burdened by frequent diagnostic and therapeutic pitfalls in clinical practice. This manuscript posits a number of similarities with Crohn's disease, which may help optimize EoE patient management. Commonalities include epidemiologic trends (Westernized diseases, rising incidence, early-life risk factors), diagnostic considerations (symptoms are poor predictors of disease activity, difficulties in disease activity assessment) and therapeutic issues (similar natural history and therapeutic goals, induction and maintenance phases, combination of drug and endoscopic treatment, potential drug interchangeability, long-term unsolved issues). Physicians devoted to EoE should learn from the extraordinary achievements fulfilled in Crohn's disease: increased disease awareness, multidisciplinary specialized clinics, structured childhood and transition programs, and an ongoing roadmap for personalized treatments, including genetic susceptibility, risk factors for progression, genotype-phenotype correlation, drug monitoring and microbial data.

The role of proton pump inhibitor therapy in the management of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic esophageal disease characterized by a Th2 inflammatory response triggered by food/environmental allergens. Solid data confirm that up to half of patients with suspected EoE achieve complete remission on proton pump inhibitors (PPI) therapy. This disease phenotype is currently labelled as PPI-responsive esophageal eosinophilia (PPI-REE). Albeit initially believed to represent gastro-esophageal reflux disease (GERD), evolving evidence has underscored that PPI-REE and EoE show a significant overlap regarding clinic, endoscopic, histologic, Th2 immune-mediated inflammation and gene expression features. Moreover, PPI therapy can effectively reverse Th2 inflammation and the EoE transcriptome expression in PPI-REE patients. Therefore, EoE and PPI-REE likely represent a common allergic disorder, where PPI therapy should be considered a short- and long-term therapeutic asset, along with diet and topical steroids.

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.