Therapeutic end points in eosinophilic esophagitis: is elimination of esophageal eosinophils enough?

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

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

The use of impedance planimetry (Endoscopic Functional Lumen Imaging Probe, EndoFLIP® ) in the gastrointestinal tract: A systematic review

BACKGROUND AND PURPOSE

The EndoFLIP® system is a method of delineating impedance and was first designed to investigate the characteristics of the esophago-gastric junction. In the last decade, its use was widened to investigate other sphincteric and non-sphincteric systems of the gastrointestinal tract. The objective of the present systematic review was to summarize the available data in literature on the use of the EndoFLIP® system in the gastrointestinal tract, including sphincteric and non-sphincteric regions. We performed a systematic review in accordance with recommendations for systematic review using PRISMA guidelines without date restriction, until June 2020, using MEDLINE-PubMed, Cochrane Library, and Google Scholar databases. Only articles written in English were included in the present review. Five hundred and six unique citations were identified from all database combined. Of those, 95 met the inclusion criteria. There was a lack of standardization among studies in terms of anesthetic drugs use, probe placement, and inflation protocol. In most cases, only small cohorts of patients were included. Most studies investigated the EGJ, with a potential use of the EndoFLIP® to identify a subgroup of patients with achalasia and for intraoperative assessment of treatment efficacy in achalasia. However, the use of EndoFLIP® in the esophageal body (esophageal panometry), other esophageal diseases (gastro-esophageal reflux disease, eosinophilic esophagitis), and other sphincter regions (anal canal, pylorus) will need further confirmatory studies. The EndoFLIP® system provides detailed geometric data of the gastrointestinal lumen but further works are needed to determine its use in clinical practice.

A Conceptual Approach to Understanding Treatment Response in Eosinophilic Esophagitis

While the diagnosis and initial treatment of eosinophilic esophagitis are becoming more standardized, there are still major gaps in knowledge related to measuring treatment response. One such question centers on how to measure treatment response and what treatment endpoints should be. This impacts not only patient care and engagement in decision-making, but also the field of drug development. In addition, studies so far have use a myriad of treatment endpoints including over a dozen histologic endpoint criteria. This review will discuss the various stakeholders involved in assessment of treatment endpoints of a complex condition, including patients, practitioners and regulatory agencies, and the care settings in which treatment response is assessed, including routine clinical care, clinical trials, and observational studies. Potential parameters or treatment endpoints such as histology, symptoms, patient-reported outcomes, endoscopy, and biomarkers are discussed along with associated challenges and opportunities. A framework on how to define treatment outcomes is discussed and a conceptual approach treatment response is proposed. This takes into account histology, symptoms, and endoscopic findings and harnesses existing, validated tools. It includes definitions of nonresponse, complete normalization, and a graded response category between these 2 extremes, and also permits flexibility and latitude for modifications as newer knowledge emerges. In addition, ways to position the pediatric population in these endeavors are discussed as are future research directions.

Clinical and Molecular Factors Associated With Histologic Response to Topical Steroid Treatment in Patients With Eosinophilic Esophagitis

BACKGROUND & AIMS

Few factors have been identified that can be used to predict response of patients with eosinophilic esophagitis (EoE) to topical steroid treatment. We aimed to determine whether baseline clinical, endoscopic, histologic, and molecular features of EoE can be used to predict histologic response.

METHODS

We collected data from 97 patients with EoE, from 2009 through 2015, treated with a topical steroid for 8 weeks; 59 patients had a histologic response to treatment. Baseline clinicopathologic features and gene expression patterns were compared between patients with a histologic response to treatment (<15 eos/hpf) and non-responders (≥15 eos/hpf). We performed sensitivity analyses for alternative histologic response definitions. Multivariate logistic regression was performed to identify predictive factors associated with response to therapy, which were assessed with area under the receiver operator characteristic (AUROC) curves.

RESULTS

Baseline dilation was the only independent predictor of non-response (odds ratio [OR], 0.30; 95% CI, 0.10-0.89). When an alternate response (<1 eos/hpf) and non-response (<50% decrease in baseline eos/hpf) definition was used, independent predictors of response status were age (OR, 1.08; 95% CI, 1.02-1.14), food allergies (OR, 12.95; 95% CI, 2.20-76.15), baseline dilation (OR, 0.17; 95% CI, 0.03-0.88), edema or decreased vascularity (OR, 0.20; 95% CI, 0.04-1.03), and hiatal hernia (OR, 0.07; 95% CI, 0.01-0.66). Using these 5 factors, we developed a predictive model that discriminated complete responders from non-responders with an AUROC of 0.88. Baseline gene expression patterns were not associated with treatment response and did not change with different histologic response thresholds.

CONCLUSIONS

In an analysis of 97 patients with EoE, we found dilation to be the only baseline factor associated with non-response to steroid treatment (<15 eos/hpf). However, a model comprising 5 clinical, endoscopic, and histologic factors identified patients with a complete response (<1 eos/hpf). A baseline gene expression panel was not predictive of treatment response at any threshold.

Prospective assessment of disease-specific quality of life in adults with eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an important cause of upper gastrointestinal dysfunction in children and adults. The EoE-quality of life (QOL)-A was validated as a disease-specific measure of quality of life in EoE. This study characterized the extent of QOL concerns in a cohort of adult EoE patients and delineated the relationships between QOL and other disease activity measures. One hundred sixty-seven patients enrolled in this prospective cohort study. Patients with established and suspected EoE undergoing endoscopy at a single university-based medical center were recruited. EoE was diagnosed on the basis of the clinical criteria and histologic demonstration of ≥15 eos/hpf while on proton pump inhibition therapy. Sixty five patients undergoing repeat endoscopy during the enrollment period participated twice. Patients provided demographic information and completed symptom assessments and the EoE-QOL-A. Analyses included comparisons with overall QOL as well as QOL subscales. Outcome measures included endoscopic activity using a validated instrument, the EoE Endoscopic Reference Score, and histology. Overall QOL was significantly correlated with dysphagia frequency, intensity, and severity (P < 0.001). Patients who experienced a food impaction in the last 30 days had significantly worse overall QOL (P = 0.009). There was no correlation between overall QOL and years since diagnosis, symptom duration, endoscopic features, or histologic findings. Patient symptoms correlated with endoscopic features of edema, rings, and stricture severity. Histologic activity was highly correlated with severity of endoscopic features. Patients who underwent repeat endoscopy with histologic response demonstrated improved eating and social QOL; however, overall QOL was unchanged. In adults with EoE, patient reported QOL is associated with symptom severity but not endoscopic or histologic features. Disease-specific QOL may complement parameters of biologic activity in the assessment of overall disease burden in EoE.

Optimal Histologic Cutpoints for Treatment Response in Patients With Eosinophilic Esophagitis: Analysis of Data From a Prospective Cohort Study

BACKGROUND AND AIMS

No prospective studies substantiate 15 eos/hpf as an appropriate endpoint for treatment of eosinophilic esophagitis (EoE). We aimed to determine a histologic cutpoint that identifies successful treatment of EoE by assessing symptomatic and endoscopic improvement.

METHODS

We performed a prospective cohort study of 62 consecutive adult patients undergoing outpatient esophagogastroduodenoscopy at the University of North Carolina from 2009 through 2014. At diagnosis of EoE and after 8 weeks of standard treatment, symptom and endoscopic responses were measured using a visual analogue scale and an endoscopic severity score (ESS), and eosinophil counts were assessed. Receiver operator curves and logistic regression models evaluated the histologic threshold that best predicted symptomatic and endoscopic response. For symptoms, analysis was limited to patients without baseline esophageal dilation.

RESULTS

The mean eosinophil count at diagnosis was 124 eos/hpf, falling to 35 eos/hpf after treatment. The mean visual analogue scale decreased from 3.4 at baseline to 1.7 after treatment, and the mean ESS decreased from 3 to 1.6. Twenty-nine patients had symptom responses (47%) and 34 had endoscopic responses (55%). Post-treatment eosinophil count thresholds of 8, 15, and 5 eos/hpf best predicted symptom, endoscopic and combined responses, respectively. On logistic regression, decreasing eosinophil count was significantly associated with the probability of symptomatic (P = .01) and endoscopic response (P < .001).

CONCLUSIONS

In a prospective study of patients with EoE, we found that a cutpoint of <15 eos/hpf identifies most patients with symptom and endoscopic improvements, providing support for the current diagnostic threshold. A lower threshold (<5 eos/hpf) identifies most patients with a combination of symptom and endoscopic responses; this cutpoint might be used in situations that require a stringent histologic threshold.

Pharmacologic Treatment of Eosinophilic Esophagitis: An Update

Eosinophilic esophagitis (EoE) is defined as a chronic, immune-medicated or antigen-mediated, esophageal disease, characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation. Food allergens are identified in most patients. Treatment strategies include elimination diets, drugs, and esophageal dilation. This article focuses on pharmacologic treatment. Currently, there is no pharmacologic treatment that has been approved by regulatory authorities. Established pharmacologic options to treat EoE include proton pump inhibitors and swallowed topical steroids. Several biologic therapies are currently under evaluation and some of them have shown promising results in improving biologic endpoints and patient-reported outcomes.

Creating a multi-center rare disease consortium - the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR)

 Eosinophilic gastrointestinal disorders (EGIDs) affect various segments of the gastrointestinal tract. Since these disorders are rare, collaboration is essential to enroll subjects in clinical studies and study the broader population. The Rare Diseases Clinical Research Network (RDCRN), a program of the National Center for Advancing Translational Sciences (NCATS), funded the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR) in 2014 to advance the field of EGIDs. CEGIR facilitates collaboration among various centers, subspecialties, patients, professional organizations and patient-advocacy groups and includes 14 clinical sites. It has successfully initiated two large multi-center clinical studies looking to refine EGID diagnoses and management. Several pilot studies are underway that focus on various aspects of EGIDs including novel therapeutic interventions, diagnostic and monitoring methods, and the role of the microbiome in pathogenesis. CEGIR currently nurtures five physician-scholars through a career training development program and has published more than 40 manuscripts since its inception. This review focuses on CEGIR's operating model and progress and how it facilitates a framework for exchange of ideas and stimulates research and innovation. This consortium provides a model for progress on other potential clinical areas.

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.

Eosinophilic esophagitis. The North against the South? A bio-economic-social mechanistic approach and clinical implications

Eosinophilic esophagitis is a chronic antigen-mediated disease characterized by esophageal symptoms, esophageal eosinophilia, and the absence of response to proton pump inhibitors. It is the most frequent cause of dysphagia and food impaction in adults. Its incidence and prevalence is very high in the developed countries (USA, Europe, Australia), where its connotation is that of an emerging epidemic. While studies have been published with large case series in the developed countries, those published in Latin America are small or consist of isolated case reports. The differences in the prevalence of the disease between the developed and developing regions are unknown. Genetic or racial causes have been cited. Nevertheless, the epidemic nature of the disease suggests that environmental causes are the most powerful. Based on the published hypotheses, as well as on epidemiologic studies, the present review discusses some of the possible causes of the disparity in the prevalence of eosinophilic esophagitis between the two types of countries. The 'hygiene hypothesis' is reviewed, together with the possible relation of Helicobacter pylori, intestinal parasites, and modifications of the esophageal microbiota in patients with eosinophilic esophagitis. In reference to studies conducted in the United States, the clinical behavior and progression of eosinophilic esophagitis in Hispanics is reviewed and a possible predominant phenotype in Mexican and other Latin American patients is discussed. Finally, based on the above, an algorithm for studying the disease in the Latin American countries is proposed.

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.

A visual analogue scale and a Likert scale are simple and responsive tools for assessing dysphagia in eosinophilic oesophagitis

BACKGROUND

While symptom scores have been developed to evaluate dysphagia in eosinophilic oesophagitis (EoE), their complexity may limit clinical use.

AIM

To evaluate a visual analogue scale (VAS) and a 10-point Likert scale (LS) for assessment of dysphagia severity before and after EoE treatment.

METHODS

We conducted a prospective cohort study enrolling consecutive adults undergoing out-patient endoscopy. Incident cases of EoE were diagnosed per consensus guidelines. At diagnosis and after 8 weeks of treatment, symptoms were measured using the VAS, LS and the Mayo Dysphagia Questionnaire (MDQ). The percentage change in scores before and after treatment were compared overall, in treatment responders (<15 eos/hpf) and non-responders, and in patients without baseline dilation.

RESULTS

In 51 EoE cases, the median VAS decreased from 3.6 at baseline to 1.4 post-treatment (71% decrease), the LS decreased from 6 to 2 (67%) and the MDQ decreased from 20 to 10 (49%). The VAS correlated with both the LS (R = 0.77; P < 0.0001) and MDQ (R = 0.46, P = 0.001). After stratification by histological response, the LS decreased 70% in responders vs. 13% in non-responders (P = 0.02). In patients who did not receive baseline dilation, both the VAS and LS decreased significantly more in the histological responders.

CONCLUSIONS

Both the VAS and LS were responsive to successful treatment as measured by histologic improvement. Because the VAS and LS are simple to administer and are responsive to treatment, they can provide an efficient and objective method for assessing dysphagia severity in EoE in clinical practice.

Budesonide Oral Suspension Improves Symptomatic, Endoscopic, and Histologic Parameters Compared With Placebo in Patients With Eosinophilic Esophagitis

BACKGROUND & AIMS

Pharmacologic treatment of eosinophilic esophagitis (EoE) is limited to off-label use of corticosteroids not optimized for esophageal delivery. We performed a randomized, controlled phase 2 trial to assess the ability of budesonide oral suspension (BOS), a novel muco-adherent topical steroid formulation, to reduce symptoms and esophageal eosinophilia in adolescents and adults with EoE.

METHODS

In this multicenter, randomized, double-blind, placebo-controlled, parallel-group trial, 93 EoE patients between the ages of 11 and 40 years with dysphagia and active esophageal eosinophilia were randomized to receive either BOS 2 mg or placebo twice daily for 12 weeks. Co-primary outcomes were change in Dysphagia Symptom Questionnaire (DSQ) score from baseline, and proportion of patients with a histologic response (≤6 eosinophils/high-power field) after treatment. Endoscopic severity scores and safety parameters were assessed.

RESULTS

At baseline, mean DSQ scores were 29.3 and 29.0, and mean peak eosinophil counts were 156 and 130 per hpf in the BOS and placebo groups, respectively. After treatment, DSQ scores were 15.0 and 21.5, and mean peak eosinophil counts were 39 and 113 per high-power field, respectively (P < .05 for all). For BOS vs placebo, change in DSQ score was -14.3 vs -7.5 (P = .0096), histologic response rates were 39% vs 3% (P < .0001), and change in endoscopic severity score was -3.8 vs 0.4 (P < .0001). Adverse events were similar between groups.

CONCLUSIONS

Treatment with BOS was well tolerated in adolescent and young adult patients with EoE and resulted in improvement in symptomatic, endoscopic, and histologic parameters using validated outcome instruments. ClinicalTrials.gov ID NCT01642212.

A Gene Expression Panel is Accurate for Diagnosis and Monitoring Treatment of Eosinophilic Esophagitis in Adults

Objective:

Eosinophilic esophagitis (EoE) can be difficult to diagnose. We aimed to evaluate whether a gene expression score could differentiate adult EoE cases from non-EoE controls and to determine whether scores normalized after treatment for EoE.

Methods:

We analyzed prospectively collected esophageal biopsies from EoE patients (diagnosed as per consensus guidelines and after a proton pump inhibitor trial) and non-EoE controls. Gene expression for a previously constructed 94 gene panel was quantified for a single RNA-later preserved biopsy. For diagnosis, a summary expression score and the area under the receiver operating characteristic curve (AUC) were calculated. For treatment response (defined as <15 eosinophils per high-power field), pretreatment and posttreatment EoE samples were compared.

Results:

For 91 EoE cases and 174 controls, gene scores for EoE cases were lower than non-EoE controls (mean 198 vs. 420; P<0.001), with an AUC of 0.927. A score ≤263 yielded a positive predictive value=91% a score ≥349 yielded a negative predictive value=90% only 12% of subjects had an indeterminate score (264–348) by this classification scheme. For the 89 EoE cases with paired pretreatment and posttreatment samples, overall gene scores improved after treatment from 199 to 343 (P<0.001). This normalization was seen only in cases with histological response (202 vs. 425; P<0.001); scores were unchanged in non-responders (189 vs. 226; P=0.25).

Conclusions:

A gene expression score has high diagnostic utility for distinguishing EoE patients from non-EoE controls in adults and can be used in clinical algorithms. Because it is highly responsive to treatment, the test could be used to monitor disease status.

Endoscopic Features and Eosinophil Density Are Associated with Food Impaction in Adults with Esophageal Eosinophilia

BACKGROUND AND AIMS

Food impaction has been described in both eosinophilic esophagitis and proton pump inhibitor-responsive esophageal eosinophilia. The association between endoscopic/histologic features of esophageal eosinophilia and food impaction remains unclear. We aimed to identify clinical, endoscopic, and histologic findings associated with a history of food impaction in esophageal eosinophilia.

METHODS

This was a retrospective cohort study of adult esophageal eosinophilia patients at a tertiary center in 6/2005-10/2014. Only patients with ≥15 eosinophils/high-power field on mucosal biopsies were included. Demographics, comorbidities, symptoms, endoscopic/histologic findings on initial endoscopy, and history of food impaction were reviewed. Statistical analyses were performed using Fisher's exact test (univariate) and forward stepwise logistic regression (multivariate).

RESULTS

400 patients (42 ± 14 years, 61 % male) were included, with 78 (20 %) having food impaction history. On univariate analyses, rings (62 vs 42 %, p = 0.003), erosions (12 vs 5 %, p = 0.03), eosinophil density on biopsy (40 [IQR = 30-50] vs 30 [IQR = 15-50], p = 0.004), and dysphagia (88 vs 62 %, p < 0.0001) were more prevalent among patients with food impaction history, while heartburn (10 vs 33 %, p < 0.0001) and abdominal pain (1 vs 12 %, p = 0.002) were less common. On multivariate analysis, rings (OR 2.6, p = 0.002), erosions (OR 3.2, p = 0.02), and eosinophil density (β-coefficient = 0.01, p = 0.04) remained associated with food impaction.

CONCLUSIONS

Findings of rings and erosions on endoscopy and increased eosinophil density on histology were independently associated with a history of food impaction in adult esophageal eosinophilia patients. Food impaction may result from both active inflammation (erosions and increased eosinophil density) and chronic fibrostenotic changes (rings).

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.

Systematic review of outcome measures in pediatric eosinophilic esophagitis treatment trials

Background

Heterogeneity has been noted in the selection and reporting of disease-specific, pediatric outcomes in randomized controlled trials (RCTs). The consequence is invalid results or difficulty comparing results across trials. The primary objective of this systematic review was to assess primary outcome and outcome measure selection and reporting, in pediatric eosinophilic esophagitis (EoE) treatment trials. As secondary objectives, we compared trial disease definition to established concensus guidelines, and the efficacy of current EoE treatments.

Methods

We searched MEDLINE, EMBASE, The Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL since 2001. We also searched clinical trial registries (portal.nihr.ac.uk; clinicaltrials.gov; isrctn.com; and anzctr.org.au) and references of included studies. We included RCTs of EoE treatment in patients 0–18 years. Two authors independently assessed articles.

Results

Eleven studies met inclusion criteria. All identified primary outcomes, however, of 9 unique primary outcomes, only 2 were used in more than one study. In total, 25 unique primary and secondary outcome measures were employed for pediatric EoE treatment trials. Measurement properties and rationale for their selection was rarely provided. Uptake of consensus-based diagnostic criteria was 25 % in trials initiated after 2011. Due to the small number and heterogeneity of studies obtained, no meta-analysis of treatment efficacy could be undertaken. This SR was limited to exclusively pediatric RCTs.

Conclusions

The results of this study confirm the need for a standardized set of core outcomes that are universally reported in pediatric EoE trials. Consistent disease definition and standardized outcome reporting will facilitate meta-analyses across similar trials and inform future clinical decision-making.

Systematic review registration number CRD42013003798

Advances in the endoscopic evaluation of eosinophilic esophagitis

PURPOSE OF REVIEW

Endoscopic detection of mucosal healing has emerged as a primary therapeutic endpoint in inflammatory bowel disease. Endoscopically identified esophageal features are increasingly being utilized in diagnostic and therapeutic decisions in eosinophilic esophagitis (EoE).

RECENT FINDINGS

Studies over the past 5 years have demonstrated the validity, accuracy, and clinical relevance of a systematic, endoscopic assessment of esophageal abnormalities in EoE. The initial severity of EoE endoscopic findings has important implications with regard to therapeutic options, including the need for dilations, and may be an important predictor of the effectiveness of medical therapies. Moreover, endoscopic parameters can serve as reliable therapeutic endpoints that substantiate the interpretation of currently used metrics of patient-reported symptom outcomes and eosinophil density. Finally, tools such as endosonography and functional luminal imaging probe are providing fundamental insights regarding the remodeling consequences of EoE that are the central determinants of disease complications.

SUMMARY

Endoscopic features are having an increasing role in the diagnosis, phenotype characterization, and choice of therapies for EoE. Comprehensive assessment of therapeutics in EoE should ideally incorporate symptoms, histology, and endoscopic healing.

Eosinophilic Esophagitis: Impact of Latest Insights Into Pathophysiology on Therapeutic Strategies

Eosinophilic esophagitis (EoE) has been defined as a 'chronic, immune/antigen-mediated, esophageal disease, characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation'. A peak value of ≥15 eosinophils/high power field has been defined as histologic diagnostic cutoff. Other conditions associated with esophageal eosinophilia, such as gastro-esophageal reflux disease, PPI-responsive esophageal eosinophilia or Crohn's disease, need to be ruled out before EoE can be diagnosed. Males are affected more frequently than females and most of the patients have concomitant allergies. Currently, the EoE prevalence is about 1 of 2,000 inhabitants in Westernized countries. The first EoE patients were described only 2 decades ago. Despite this short period, considerable progress has been made regarding the understanding of the pathophysiology, natural history, assessment of disease activity and with respect to evaluating different therapeutic options. Untreated EoE can lead to esophageal remodeling with reduced compliance and stricture formation, which represents the main risk factor for food bolus impactions. The therapeutic options can be summarized with the 3 D's, which stand for drugs, diets and dilation. Of note, as of yet, there is no EoE-specific drug that has been approved by regulatory authorities. This is, among other reasons, related to the lack of validated outcome measurement instruments until recently. Swallowed topical steroids such as budesonide or fluticasone represent the standard of care for treating symptomatic pediatric and adult EoE patients with inflammatory activity. Several trials have already evaluated different biologic therapies, such as anti-interleukin-5 or anti-IgE. Further studies are on the way. As a non-pharmacologic alternative, different dietary regimens exist. Dilation can offer long-lasting symptomatic response in case of stricturing EoE but does not have any impact on the underlying inflammation. This review highlights the latest insights regarding pathophysiology and its impact regarding current and future therapeutic strategies.

Prospective assessment of the diagnostic utility of esophageal brushings in adults with eosinophilic esophagitis

Patients with eosinophilic esophagitis (EoE) undergo multiple endoscopies with biopsy for both diagnosis and assessment of treatment response, which is inconvenient and costly. Brush cytology has been examined in Barrett's esophagus to reduce the need for repeated endoscopic biopsies. The aim of this pilot study was to evaluate the ability of brush cytology to detect mucosal eosinophilia in patients with EoE. This prospective study included adults with untreated and treated esophageal eosinophilia undergoing endoscopy at a tertiary care center. Patients received paired brushings and biopsies at the proximal and distal esophagus. A blinded pathologist quantified the number of eosinophils and epithelial cells per high-power field (hpf) on the cytology slides. The ratio of eosinophils/epithelial cells was used to normalize the cytology specimens for density of cells collected. The main outcome measures were sensitivity and specificity of brush cytology, and correlation between cytology and histology. Twenty-eight patients enrolled. The average age of the cohort was 37.7 ± 10.4 years; 75% of subjects were male. The sensitivity of cytology was 67-69% at the proximal esophagus and 70-72% at the distal esophagus. The specificity was 61-67% proximally and 70-75% distally. Histology was not significantly correlated with the max ratio of eosinophils/epithelial cells per hpf or the absolute number of eosinophils on cytology slides. Cytology using esophageal brushing has limited sensitivity and specificity for the detection of esophageal mucosal eosinophilia. The presence of exudates on endoscopy increased the detection of eosinophilia, which could make cytology useful in pediatric EoE, which often has a more exudative presentation. Diagnostic yield may improve with alternative acquisition techniques or the incorporation of eosinophil degranulation proteins.

Evaluation of Histologic Cutpoints for Treatment Response in Eosinophilic Esophagitis

AIM

No consensus exists on the definition of successful treatment in eosinophilic esophagitis (EoE). The aim of this study was to identify the optimal histologic cutpoint to define successful treatment of EoE by assessing rates of symptomatic and endoscopic improvement.

MATERIALS AND METHODS

We performed a retrospective cohort study utilizing the University of North Carolina EoE Clinicopathologic Database between 2006 and 2013. Rates of symptomatic and endoscopic improvement were determined, as were post-treatment eosinophil counts. The area under the receiver operator characteristic curve (AUC) was calculated for symptomatic and endoscopic response at several possible eosinophil count cutpoints (eos/hpf). Predictors of response were also assessed.

RESULTS

Of 224 treatments in 199 patients, 76% were associated with symptomatic improvement, 68% with endoscopic improvement, and 60% with both. Of treatments that resulted in a post-treatment count of <15 eos/hpf, 90% were associated with an endoscopic response, 88% with a symptomatic response, and 81% with both symptomatic and endoscopic responses. Using a <15 eos/hpf threshold, the area under the curves (AUCs) were 0.70, 0.78, and 0.75 for symptomatic, endoscopic, and symptomatic/endoscopic responses, respectively. Lower histologic cut-points did not result in a substantial gain in response, but decreased the AUC.

CONCLUSION

In this large cohort of EoE patients, rates of symptomatic and endoscopic improvement were generally associated with histologic improvement. A histologic cutoff for treatment response of <15 eos/hpf may balance clinical outcomes and test performance.

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.

Predictors of response to steroid therapy for eosinophilic esophagitis and treatment of steroid-refractory patients

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is commonly treated with swallowed (topical) corticosteroids (tCS). However, few factors have been described that predict outcomes of steroid therapy. We aimed to identify factors associated with nonresponse to tCS and report outcomes of second-line treatment for patients with steroid-refractory EoE.

METHODS

We performed a retrospective cohort study by using the University of North Carolina EoE Clinicopathologic Database to identify patients who received tCS for EoE from 2006 through 2013. Demographic, symptom, endoscopic, and histologic data were extracted from medical records. Immunohistochemistry was performed on archived biopsies. Responders and nonresponders to tCS were compared.

RESULTS

Of 221 patients with EoE who received tCS, 71% had endoscopic improvement, 79% had symptomatic improvement, and 57% had histologic response (<15 eosinophils/high-power field). After multivariate logistic regression, esophageal dilation at the baseline examination predicted nonresponse (odds ratio, 2.9; 95% confidence interval, 1.4-6.3), and abdominal pain predicted response (odds ratio for nonresponse, 0.31; 95% confidence interval, 0.12-0.83); no other clinical features were predictive. On the basis of immunohistochemical analysis, higher baseline levels of tryptase (244 vs 157 mast cells/mm(2), P = .04) and eotaxin-3 (2425 vs 239 cells/mm(2), P = .02) were associated with steroid response, but levels of major basic protein were not. Among 27 steroid-refractory patients, a mean of 2 additional therapies were tried; only 48% of the patients eventually responded to any second-line therapy.

CONCLUSIONS

On the basis of a retrospective analysis of a large group of patients with EoE, only 57% have a histologic response to steroid therapy. Baseline esophageal dilation and decreased levels of mast cells and eotaxin-3 predicted which patients would not respond to therapy. Combining clinical factors and immunohistochemistry might therefore be used to direct therapy.

Food allergy: a practice parameter update-2014

This parameter was developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology (JCAAI). The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Food Allergy: A practice parameter update-2014." This is a complete and comprehensive document at the current time. The medical environment is a changing one, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, ACAAI, and JCAAI. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Epidemiology of eosinophilic esophagitis

In this article, the epidemiology of eosinophilic esophagitis (EoE) is reviewed. Demographic features and natural history are described, the prevalence and incidence of EoE are highlighted, and risk factors for EoE are discussed. EoE can occur at any age, there is a male predominance, it is more common in whites, and there is a strong association with atopic diseases. EoE is chronic, relapses are frequent, and persistent inflammation increases the risk of fibrostenotic complications. The prevalence is currently estimated at 0.5-1 in 1000, and EoE is now the most common cause of food impaction. The incidence of EoE is approximately 1/10,000 new cases per year, and the increase in incidence is outpacing increases in recognition and endoscopy volume, but the reasons for this evolving epidemiology are not yet fully delineated.

Clinical implications and pathogenesis of esophageal remodeling in eosinophilic esophagitis

In eosinophilic esophagitis (EoE), remodeling changes are manifest histologically in the epithelium and subepithelium where lamina propria fibrosis, expansion of the muscularis propria, and increased vascularity occur. The clinical symptoms and complications of EoE are largely consequences of esophageal remodeling. Available therapies have demonstrated variable ability to reverse existing remodeling changes of the esophagus. Systemic therapies have the potential of addressing subepithelial remodeling. Esophageal dilation remains a useful, adjunctive therapeutic maneuver in symptomatic adults with esophageal stricture. As novel treatments emerge, it is essential that therapeutic end points account for the fundamental contributions of esophageal remodeling to overall disease activity.

A phenotypic analysis shows that eosinophilic esophagitis is a progressive fibrostenotic disease

BACKGROUND

Phenotypes of eosinophilic esophagitis (EoE) are not well-characterized.

OBJECTIVE

To describe clinical features of patients with EoE with predefined phenotypes, determine predictors of these phenotypes, and make inferences about the natural history of EoE.

DESIGN

Retrospective study.

SETTING

Tertiary-care center.

PATIENTS

Incident EoE cases from 2001 to 2011 that met consensus diagnostic guidelines.

INTERVENTION

Review of records.

MAIN OUTCOME MEASUREMENTS

Endoscopic phenotypes, including fibrostenotic, inflammatory, or mixed. Other groups of clinical characteristics examined included atopy, level of esophageal eosinophilia, and age of symptom onset. Multinomial logistic regression assessed predictors of phenotype status.

RESULTS

Of 379 cases of EoE identified, there were no significant phenotypic differences by atopic status or level of eosinophilia. Those with the inflammatory phenotype were more likely to be younger than those with mixed or fibrostenotic (13 vs 29 vs 39 years, respectively; P < .001) and less likely to have dysphagia, food impaction, and esophageal dilation (P < .001 for all). The mean symptom length before diagnosis was shorter for inflammatory (5 vs 8 vs 8 years; P = .02). After multivariate analysis, age and dysphagia independently predicted phenotype. The odds ratio (OR) for fibrostenosis for each 10-year increase in age was 2.1 (95% CI, 1.7-2.7). The OR for dysphagia was 7.0 (95% CI, 2.6-18.6).

LIMITATIONS

Retrospective, single-center study.

CONCLUSION

In this large EoE cohort, the likelihood of fibrostenotic disease increased markedly with age. For every 10-year increase in age, the odds of having a fibrostenotic EoE phenotype more than doubled. This association suggests that the natural history of EoE is a progression from an inflammatory to a fibrostenotic disease.

Role of advanced diagnostics for eosinophilic esophagitis

In eosinophilic esophagitis (EoE), diagnostic tests aid in the identification of pathophysiologic consequences and accurate detection of the disease. The EoE Endoscopic Reference Score (EREFS) classifies and grades the severity of the five major endoscopically identified esophageal features of EoE (edema, rings, exudates, furrows and strictures). The EREFS may be useful in the evaluation of disease severity and as an objective outcome of response to therapy. pH monitoring identifies the presence of abnormal degrees of acid exposure in the esophagus that characterizes gastroesophageal reflux disease. The presence of acid reflux, however, does not indicate that the reflux is responsible for esophageal eosinophilia. Esophageal manometry has not demonstrated a characteristic abnormality with sufficient sensitivity to make the test of diagnostic value in clinical practice. On the other hand, manometric characteristics of esophageal pressurization and longitudinal muscle dysfunction may help identify important pathophysiologic consequences of EoE. Esophageal impedance testing has demonstrated increased baseline mucosal impedance that correlates with increased epithelial permeability in EoE. Reduced mucosal integrity may provide intraluminal allergens access to antigen-presenting cells, serving as an early event in the pathogenesis of EoE. The functional luminal impedance probe (FLIP) provides quantitative assessment of esophageal mural compliance, a physiologic correlate of remodeling in EoE. Studies using FLIP have associated reductions in esophageal distensibility in EoE with the important outcome of food impaction risk. Finally, confocal endomicroscopy, multiphoton fluorescence microscopy and novel eosinophil-enhancing contrast agents are emerging methods that may allow for in vivo visualization of esophageal eosinophilic inflammation, thereby improving the detection and understanding of this emerging disease.

Eosinophilic esophagitis in adults: an update on medical management

Management of eosinophilic esophagitis (EoE) centers around the 3 Ds: diet, drug therapy, and dilation. Unfortunately, there is not a consistent relationship between symptom relief and resolution of mucosal eosinophilia. Elemental diets are very successful in children, but poorly tolerated by adults. The 6-food elimination diet is more attractive to adults, especially for those individuals with multiple food allergies. Steroids are the preferred anti-eosinophil drug for EoE. Oral prednisone is infrequently used because of side effects. Topical swallowed preparations (fluticasone, budesonide) are preferred for acute and possibly maintenance therapy. Relapses off steroids are frequent and dysphagia does not predictably improve. Esophageal dilation is key treatment for patients with the fibrostenotic phenotype of EoE. Long-term symptom relief for 1-2 years is common. Post-procedure chest pain is to be expected but perforation is very rare. A suggested algorithm for the treatment of EoE based on endoscopic phenotypes is outlined.

Esophageal distensibility as a measure of disease severity in patients with eosinophilic esophagitis

BACKGROUND & AIMS

The aim of this study was to assess whether measurements of esophageal distensibility, made by high-resolution impedance planimetry, correlated with important clinical outcomes in patients with eosinophilic esophagitis.

METHODS

Seventy patients with eosinophilic esophagitis (50 men; age, 18-68 y) underwent endoscopy with esophageal biopsy collection and high-resolution impedance planimetry using the functional lumen-imaging probe. The patients were followed up prospectively for an average of 9.2 months (range, 3-14 mo), and the risk of food impaction, requirement for dilation, and symptom severity during the follow-up period was determined from medical records. Esophageal distensibility metrics and the severity of mucosal eosinophilia at baseline were compared between patients presenting with and without food impaction and those requiring or not requiring esophageal dilation. Logistic regression and stratification assessments were used to assess the predictive value of esophageal distensibility metrics in assessing risk of food impaction, the need for dilation, and continued symptoms.

RESULTS

Patients with prior food impactions had significantly lower distensibility plateau (DP) values than those with solid food dysphagia alone. In addition, patients sustaining food impaction and requiring esophageal dilation during the follow-up period had significantly lower DP values than those who did not. The severity of mucosal eosinophilia did not correlate with risk for food impaction, the requirement for dilation during follow-up evaluation, or DP values.

CONCLUSIONS

Reduced esophageal distensibility predicts risk for food impaction and the requirement for esophageal dilation in patients with eosinophilic esophagitis. The severity of mucosal eosinophilia was not predictive of these outcomes and had a poor correlation with esophageal distensibility.

Development and field testing of a novel patient-reported outcome measure of dysphagia in patients with eosinophilic esophagitis

BACKGROUND

Dysphagia is the hallmark of eosinophilic esophagitis (EoE), but no validated dysphagia instruments in this population exist.

AIM

To develop and field test a patient-reported outcome (PRO) for dysphagia in subjects with EoE.

METHODS

This was a multi-centre/multi-phase prospective study. The first phase developed a dysphagia questionnaire using qualitative methods. The second phase was a 30-day field trial to test the instrument and assess content validity. Adolescents and adults with EoE, active symptoms of dysphagia and oesophageal eosinophilia (≥15 eosinophils per high-power field) were enrolled. Solid-food-avoidance days, dysphagia days and actions taken to get relief were recorded. A dysphagia score was calculated and compared to the Straumann Dysphagia Instrument (SDI).

RESULTS

Ten adolescents and 10 adults were included in the first phase and the Dysphagia Symptom Questionnaire (DSQ), a three-item daily electronic diary, was developed. In the second phase, 35 subjects finished the field trial (18 adults, 17 adolescents, mean age 24, 54% male, 95% white, 54% currently on topical corticosteroids). The median number of dysphagia days per week was 2 for adolescents vs. 4 for adults (P < 0.001), and 2 for those on topical steroids vs. 4 for those not on topical steroids (P < 0.001). The DSQ score strongly correlated with the number of dysphagia days (R = 0.96; P < 0.001) and the SDI (R = 0.77; P < 0.001).

CONCLUSIONS

The DSQ, a three-question patient-reported outcome, was successfully developed and field tested. The DSQ had content validity and the score accurately measured dysphagia frequency and intensity. The Dysphagia Symptom Questionnaire is suitable for use in clinical trials of EoE patients with dysphagia.

Eosinophilic esophagitis: a bulk of mysteries

Eosinophilic esophagitis (EoE), which was first described in the early 1990s, has rapidly evolved as a distinctive chronic inflammatory esophageal disease. The diagnosis is based clinically on the presence of symptoms related to esophageal dysfunction and histologically by an eosinophil-predominant inflammation once other conditions leading to esophageal eosinophilia are excluded. This striking male-prevalent disease has an increasing incidence and prevalence in the Westernized countries. Currently, EoE represents the main cause of dysphagia and bolus impaction in adult patients. Despite the fact that EoE often occurs in atopic patients, the value of allergic testing is still under discussion. Topical corticosteroids lead to a rapid improvement of active EoE clinically and histologically; they are therefore regarded as first-line drug therapy. Elimination diets have similar efficacy as topical corticosteroids, but their long-term use is limited by practical issues. Esophageal dilation of EoE-induced strictures can also be effective in improving symptoms, but this therapy has no effect on the underlying inflammation. Neither the diagnostic nor the long-term therapeutic strategies have been fully defined. Currently, the list of unsolved issues--or mysteries--is still long and a concerted effort on behalf of clinicians and scientists is required to improve the understanding and the therapeutic management of this mysterious disease.

Eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic immune-mediated condition whereby infiltration of eosinophils into the esophageal mucosa leads to symptoms of esophageal dysfunction. EoE is encountered in a substantial proportion of patients undergoing diagnostic upper endoscopy. This review discusses the clinical, endoscopic, and histologic features of EoE and presents the most recent guidelines for its diagnosis. Selected diagnostic dilemmas are described, including distinguishing EoE from gastroesophageal reflux disease and addressing the newly recognized clinical entity of proton-pump inhibitor-responsive esophageal eosinophilia. Also highlighted is evidence to support both pharmacologic and nonpharmacologic treatments, including topical corticosteroids, dietary elimination therapy, and endoscopic dilation.

Diagnosis and management of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition characterized by esophageal dysfunction and eosinophilic infiltrate in the esophageal epithelium in the absence of other potential causes of eosinophilia. EoE is increasing in incidence and prevalence, and is a major cause of gastrointestinal morbidity among children and adults. EoE is thought to be immune mediated, with food or environmental antigens stimulating a T-helper (Th)-2 inflammatory response. An increased understanding of the pathogenesis of EoE has led to the evolution of diagnostic and treatment paradigms. We review the latest approach to diagnosis of EoE and present consensus diagnostic guidelines. We also discuss the clinical, endoscopic, and histologic features of EoE and challenges to diagnosis. Finally, we present the 3 major treatment options for EoE: pharmacologic therapy, dietary modification, and endoscopic dilation.

Eosinophilic gastrointestinal diseases--clinically diverse and histopathologically confounding

Eosinophilic gastrointestinal diseases are a group of chronic diseases characterized by a range of symptoms caused by eosinophilic inflammation of various parts of the gastrointestinal tract. Other causes for eosinophilia need to be ruled out prior to making the diagnosis of EGIDs. The most common form of EGID is eosinophilic esophagitis (EoE), an antigen-driven disease that afflicts children and adults and has been identified across the world. Histological features include dense eosinophilia of the esophageal mucosa, eosinophil degranulation, eosinophil microabscess formation, and other features of epithelial inflammation including basal zone hyperplasia and rete pege elongation. Treatments include dietary exclusions and topical corticosteroids.