Reliability of histologic assessment in patients with eosinophilic oesophagitis

Histopathology of Eosinophilic Esophagitis

Microscopic examination of esophageal biopsies is essential to diagnose eosinophilic esophagitis (EoE). Eosinophil inflammation is the basis for the diagnosis, but additional abnormalities may contribute to persistent symptoms and epithelial barrier dysfunction. Both peak eosinophil count and assessments of additional features should be included in pre-therapy and post-therapy pathology reports. Pathologic abnormalities identified in esophageal biopsies of EoE are reversible in contrast to esophageal strictures.

Clinical Evaluation of the Child with Eosinophilic Esophagitis

The diagnosis of eosinophilic esophagitis (EoE) is based on clinical symptoms of esophageal dysfunction and eosinophil predominant esophageal inflammation. Clinical symptoms in children with EoE vary based on age and may be nonspecific. EoE has a male predominance with the majority having comorbid atopic disorders. At present, treatment options include medications (proton pump inhibition, swallowed topical steroids), dietary therapy or biologic therapy (dupilumab, approved for those ≥12 years of age). Outside of EoE in the context of oral immunotherapy, EoE is typically chronic requiring lifelong therapy. Long-term complications including feeding difficulties, malnutrition, and fibrostenotic disease.

Changes in mucosal IgG4+- and IL-10+-cell frequencies in adults with eosinophilic esophagitis on a two-food elimination diet

Eosinophilic esophagitis (EoE) is increasingly diagnosed in patients with dysphagia. Type-2 immunity can induce EoE histopathology via non-IgE-dependent mechanisms, possibly involving IgG4 and IL-10. To elucidate the contribution of this response to EoE pathogenesis, we examined its association with clinical and histologic endpoints in adult EoE patients given a two-food elimination diet. IgG4- and IL-10-expressing cells were counted in esophageal biopsies and serum food-specific IgG4 measured at baseline and follow-up. Variables were correlated with histologic measures of disease activity. Patients exhibited significant reduction in esophageal eosinophilia and overall histology. A significant decrease in IL-10+-cell frequencies correlated with histologic changes. In contrast, a decline in serum and esophageal IgG4, while substantial, did not correlate with IL-10+-cell frequencies or histologic parameters. These results suggest a critical role of IL-10 in EoE pathogenesis. Conversely, IgG4 expression, while reflecting exposure to food antigens, is not obviously related to EoE histopathology or IL-10 expression.

Performance of an Artificial Intelligence Model for Recognition and Quantitation of Histologic Features of Eosinophilic Esophagitis on Biopsy Samples

We have developed an artificial intelligence (AI)-based digital pathology model for the evaluation of histologic features related to eosinophilic esophagitis (EoE). In this study, we evaluated the performance of our AI model in a cohort of pediatric and adult patients for histologic features included in the Eosinophilic Esophagitis Histologic Scoring System (EoEHSS). We collected a total of 203 esophageal biopsy samples from patients with mucosal eosinophilia of any degree (91 adult and 112 pediatric patients) and 10 normal controls from a prospectively maintained database. All cases were assessed by a specialized gastrointestinal (GI) pathologist for features in the EoEHSS at the time of original diagnosis and rescored by a central GI pathologist (R.K.M.). We subsequently analyzed whole-slide image digital slides using a supervised AI model operating in a cloud-based, deep learning AI platform (Aiforia Technologies) for peak eosinophil count (PEC) and several histopathologic features in the EoEHSS. The correlation and interobserver agreement between the AI model and pathologists (Pearson correlation coefficient [rs] = 0.89 and intraclass correlation coefficient [ICC] = 0.87 vs original pathologist; rs = 0.91 and ICC = 0.83 vs central pathologist) were similar to the correlation and interobserver agreement between pathologists for PEC (rs = 0.88 and ICC = 0.91) and broadly similar to those for most other histologic features in the EoEHSS. The AI model also accurately identified PEC of >15 eosinophils/high-power field by the original pathologist (area under the curve [AUC] = 0.98) and central pathologist (AUC = 0.98) and had similar AUCs for the presence of EoE-related endoscopic features to pathologists' assessment. Average eosinophils per epithelial unit area had similar performance compared to AI high-power field-based analysis. Our newly developed AI model can accurately identify, quantify, and score several of the main histopathologic features in the EoE spectrum, with agreement regarding EoEHSS scoring which was similar to that seen among GI pathologists.

Esophageal Epithelium and Lamina Propria Are Unevenly Involved in Eosinophilic Esophagitis

BACKGROUND & AIMS

The nature of the involvement of esophageal tissue in eosinophilic esophagitis (EoE) is unclear. We estimated the intrabiopsy site agreements of the EoE Histologic Scoring System (EoEHSS) scores for the grade (degree) and stage (extent) of involvement of the esophageal epithelial and lamina propria and examined if the EoE activity status influenced the intrabiopsy site agreement.

METHODS

Demographic, clinical, and EoEHSS scores collected as part of the prospective Outcome Measures for Eosinophilic Gastrointestinal Diseases Across Ages study were analyzed. A weighted Cohen's kappa agreement coefficient (k) was used to calculate the pairwise agreements for proximal:distal, proximal:middle, and middle:distal esophageal biopsy sites, separately for grade and stage scores, for each of the 8 components of EoEHSS. A k > 0.75 was considered uniform involvement. Inactive EoE was defined as fewer than 15 eosinophils per high-powered field.

RESULTS

EoEHSS scores from 1263 esophageal biopsy specimens were analyzed. The k for the stage of involvement of the dilated intercellular spaces across all 3 sites in inactive EoE was consistently greater than 0.75 (range, 0.87-0.99). The k for lamina propria fibrosis was greater than 0.75 across some of the biopsy sites but not across all 3. Otherwise, the k for all other features, for both grade and stage, irrespective of the disease activity status, was 0.75 or less (range, 0.00-0.74).

CONCLUSIONS

Except for the extent of involvement of dilated intercellular spaces in inactive EoE, the remaining epithelial features and lamina propria are involved unevenly across biopsy sites in EoE, irrespective of the disease activity status. This study enhances our understanding of the effects of EoE on esophageal tissue pathology.

Eosinophilic Esophagitis Histologic Scoring System: Correlation with Histologic, Endoscopic, and Symptomatic Disease and Clinical Use

BACKGROUND

The eosinophilic esophagitis histologic scoring system (EoEHSS) was developed to enhance the diagnostic standard of peak eosinophil count (PEC) in evaluating disease activity in EoE.

AIMS

(1) Correlate the EoEHSS and PEC to measures of symptomatic and endoscopic disease activity, (2) Correlate EoEHSS grade and stage subcomponents to clinical, radiology, and endoscopic markers of fibrotic disease, (3) Evaluate EoEHSS remission in asymptomatic patients with PEC < 15 eosinophils per high powered field (eos/hpf).

METHODS

Secondary analysis of prospective cohort data of 22 patients with EoE that underwent dietary therapy and endoscopy at 3 time points. Active disease was defined by EoEHSS grade or stage > 0.125, symptomatic disease by EoE symptom activity index > 20, endoscopic disease by endoscopic reference score > 2, and histologic disease by PEC ≥ 15 eos/hpf. EoEHSS remission was defined by esophageal inflammation (EI) grade of 0-1, EI stage of 0, total grade ≤ 3, and total stage ≤ 3.

RESULTS

EoEHSS grade and stage did not correlate with symptomatic disease but did with endoscopic and histologic disease. PEC showed similar correlation pattern. Abnormal grade and stage had strong sensitivity (87-100%) but poor specificity (11-36%) to detect symptomatic, endoscopic, and histologic disease activity. Lamina propria fibrosis was evaluated in 36% of biopsies and did not correlate with minimum esophageal diameter. Out of 14 patients who were in complete symptomatic, endoscopic, and histologic remission, 8 met criteria for EoEHSS remission.

CONCLUSION

The positive and negative correlations of EoEHSS to specific measures of symptomatic, histologic, and endoscopic activity suggest that it provides complementary information in EoE.

The role of biologics in pediatric food allergy and eosinophilic gastrointestinal disorders

Continuing insight into the molecular mechanisms of atopic disorders has enabled the development of biologics to precisely target these diseases. Food allergy (FA) and eosinophilic gastrointestinal disorders (EGIDs) are driven by similar inflammatory molecular mechanisms and exist along the same atopic disease spectrum. Therefore, many of the same biologics are being investigated to target key drivers of mechanisms shared across the disease states. The enormous potential of biologics for the treatment of FA and EGIDs is highlighted by the significant increases in the number of ongoing clinical trials (more than 30) evaluating their use in these disease states, as well as by the recent US Food and Drug Administration approval of dupilumab for the treatment of eosinophilic esophagitis. Here we discuss past and current research into the use of biologics in FA and EGIDs and their potential role in improving treatment options in the future, with the need to have biologics widely clinically available.

Challenges in Inter-rater Agreement on Lamina Propria Fibrosis in Esophageal Biopsies

BACKGROUND

Mucosal biopsies in eosinophilic esophagitis (EoE) can exhibit lamina propria (LP) fibrosis, which may portend stenotic complications; however, the histologic diagnosis of LP fibrosis is subjective. We sought to assess and improve the consistency of LP fibrosis diagnosis among our pathologist group.

METHODS

At a large pediatric hospital, 25 esophageal biopsy slides from 19 patients (16 with EoE) exhibiting a wide spectrum of LP area, artifacts, and fibrosis severity were scanned into whole-slide images. Staff pediatric pathologists (n = 8) separate from the authors classified each biopsy by LP adequacy and fibrosis severity 1 month before and after completion of an educational tutorial. Consensus was defined as >70% agreement.

RESULTS

At baseline, 16/25 (64%) cases reached consensus for no fibrosis (n = 3), fibrosis (n = 7), or inadequate LP (n = 6); agreement was fair (α = 0.34). Post-tutorial, 13/25 (52%) cases reached consensus for no fibrosis (n = 2), fibrosis (n = 7), or inadequate LP (n = 4); agreement was again fair (α = 0.33). There was moderate agreement in grading of fibrosis severity (α = 0.54).

CONCLUSION

We document only fair-to-moderate agreement in the diagnosis of esophageal LP fibrosis and adequacy in a large pediatric pathologist group despite targeted education, highlighting a challenge in incorporating this feature into EoE research and clinical decision-making.

Application of the Eosinophilic Esophagitis Histology Scoring System Grade Scores in Patients at British Columbia Children's Hospital

INTRODUCTION

Histologic diagnosis of eosinophilic esophagitis (EoE) involves peak eosinophil counts (PEC) being greater than 15 per high power field. The EoE Histology Scoring System (EoEHSS) was developed to comprehensively evaluate biopsies to better predict symptom and endoscopy response; we aimed to validate the EoEHSS in our provincial registry, where EoEHSS had not been employed.

METHODS

We reviewed 186 esophageal biopsies from 16 patients at diagnosis and follow-up. Statistical analyses were conducted to quantify how grade scores correlate with active EoE status and PEC counts, and each feature's ability to predict active disease.

RESULTS

Nearly all EoEHSS variables were associated with active EoE and high PEC, with basal zone hyperplasia, eosinophil abscesses, and surface epithelial alteration being most predictive in identifying active EoE.

CONCLUSIONS

We validated and demonstrated each EoEHSS variable's strength in tracking traditional PEC counts, resulting in its adoption as a standard reporting element for our research registry.

Eosinophilic esophagitis: Comparison of clinical, endoscopic and histological scoring systems

Background Eosinophilic Esophagitis (EoE) has received increasing attention as a disease entity, and it is now recognized as an important disorder of the Upper Gastrointestinal Tract. Topical corticosteroids (tCS) are effective in clinical-pathological remission induction (RI) and remission maintenance (RM) of active EoE. With scoring systems, such as clinical (SDI), endoscopic (EREFS), and histological (EoEHSS) systems, EoE can be graded, and its disease activity can be assessed.

Objective To discover how closely results within each of the three scoring systems SDI, EREFS, and EoEHSS are correlated between initial diagnosis (ID), RI, and RM, and to determine how well scores from the three systems are intercorrelated at each time point.

Methods Retrospective cohort analysis of patients with active EoE was performed between 2006 and 2020, with follow-up for up to 6 years. SDI, EREFS and EoEHSS scores were recorded at ID, at RI, and in RM. Evaluation employed descriptive statistics, the Friedman test, and Bonferroni-corrected post hoc pairwise comparisons.

Results At RI 29 and at RM 19 EoE patients provided data. Significant correlations were found between EREFS and EoEHSS at RI and in RM. Pairwise comparisons showed significant differences between ID and RI for SDI, for EREFS, and for EoEHSS.

Conclusion The scoring systems tested did not show intercorrelation at ID. Comparison revealed significant differences for SDI, EREFS, and EoEHSS between the systems at ID und RI, but not in RM, during tCS treatment. These results underline the efficacy of tCS (at RI and RM) in the treatment of active EoE.

Esophageal remodeling in eosinophilic esophagitis: Relationships to luminal captured biomarkers of inflammation and periostin

BACKGROUND

Esophageal remodeling is a factor in disease progression and symptom severity for patients with eosinophilic esophagitis (EoE). Remodeling can begin early in children, resulting in stricture and food impaction. Detection of esophageal remodeling often depends on endoscopy and is appreciated only in its later stages.

OBJECTIVE

We sought to determine whether luminal eosinophil-associated and remodeling proteins captured by the esophageal string test (EST) correlate with measures of esophageal remodeling and biomarkers of the epithelial-mesenchymal transition (EMT).

METHODS

Patients with EoE (7-18 years old) were enrolled from 2 pediatric hospitals. Participants performed the EST and underwent endoscopy. Histology, distensibility measured by endoluminal functional lumen imaging probe, and symptoms were assessed. Protein quantitation by ELISA was performed on mucosal biopsy and EST samples. Tissue sections were evaluated for EMT. Outcome measures were summarized, and Spearman ρ was used to assess bivariate correlations.

RESULTS

Forty patients (68% male) were enrolled (mean age, 12.5 years). Twenty-four (60%) had active disease (≥15 eosinophils per high-power field). EST-captured eotaxin-3, major basic protein 1, EDN, eosinophil peroxidase, and Charcot-Leyden crystal protein/galectin-10 showed significant correlations with peak eosinophils per high-power field (ρ 0.53-0.68, P < .001). Luminal proteins positively correlated with endoscopic features and markers of EMT, and negatively with esophageal distensibility. Periostin was captured by the EST and correlated with eosinophil density, basal zone hyperplasia, endoscopic appearance, and markers of EMT.

CONCLUSION

Luminal markers of esophageal remodeling in addition to biomarkers of eosinophilic inflammation correlate with epithelial and functional remodeling in EoE.

A Clinical Severity Index for Eosinophilic Esophagitis: Development, Consensus, and Future Directions

BACKGROUND & AIMS

Disease activity and severity of eosinophilic esophagitis (EoE) dictate therapeutic options and management, but the decision-making process for determining severity varies among practitioners. To reduce variability in practice patterns and help clinicians monitor the clinical course of the disease in an office setting, we aimed to create an international consensus severity scoring index for EoE.

METHODS

A multidisciplinary international group of adult and pediatric EoE researchers and clinicians, as well as non-EoE allergy immunology and gastroenterology experts, formed 3 teams to review the existing literature on histology, endoscopy, and symptoms of EoE in the context of progression and severity. A steering committee convened a 1-day virtual meeting to reach consensus on each team's opinion on salient features of severity across key clinicopathologic domains and distill features that would allow providers to categorize disease severity.

RESULTS

Symptom features and complications and inflammatory and fibrostenotic features on both endoscopic and histologic examination were collated into a simplified scoring system-the Index of Severity for Eosinophilic Esophagitis (I-SEE)-that can be completed at routine clinic visits to assess disease severity using a point scale of 0-6 for mild, 7-14 for moderate, and ≥15 for severe EoE.

CONCLUSIONS

A multidisciplinary team of experts iteratively created a clinically usable EoE severity scoring system denominated "I-SEE" to guide practitioners in EoE management by standardizing disease components reflecting disease severity beyond eosinophil counts. I-SEE should be validated and refined using data from future clinical trials and routine clinical practice to increase its utilization and functionality.

A Clinical Severity Index for Eosinophilic Esophagitis: Development, Consensus, and Future Directions

BACKGROUND & AIMS

Disease activity and severity of eosinophilic esophagitis (EoE) dictate therapeutic options and management, but the decision-making process for determining severity varies among practitioners. To reduce variability in practice patterns and help clinicians monitor the clinical course of the disease in an office setting, we aimed to create an international consensus severity scoring index for EoE.

METHODS

A multidisciplinary international group of adult and pediatric EoE researchers and clinicians, as well as non-EoE allergy immunology and gastroenterology experts, formed 3 teams to review the existing literature on histology, endoscopy, and symptoms of EoE in the context of progression and severity. A steering committee convened a 1-day virtual meeting to reach consensus on each team's opinion on salient features of severity across key clinicopathologic domains and distill features that would allow providers to categorize disease severity.

RESULTS

Symptom features and complications and inflammatory and fibrostenotic features on both endoscopic and histologic examination were collated into a simplified scoring system-the Index of Severity for Eosinophilic Esophagitis (I-SEE)-that can be completed at routine clinic visits to assess disease severity using a point scale of 0-6 for mild, 7-14 for moderate, and ≥15 for severe EoE.

CONCLUSIONS

A multidisciplinary team of experts iteratively created a clinically usable EoE severity scoring system denominated "I-SEE" to guide practitioners in EoE management by standardizing disease components reflecting disease severity beyond eosinophil counts. I-SEE should be validated and refined using data from future clinical trials and routine clinical practice to increase its utilization and functionality.

Current and emerging therapies for eosinophilic esophagitis

Background: Eosinophilic esophagitis (EoE) is a Type-2 chronic inflammatory food antigen-driven disease of the esophagus, characterized by eosinophilic predominant inflammation and a constellation of symptoms. The incidence and prevalence of EoE has increased over the past 2 decades. There is an unmet need for approved less burdensome treatment options. Objective: To describe the underlying pathophysiology and diagnosis of EoE and discuss the currently available treatment options. We also aim to review the new and emerging therapies for EoE. Methods: A search of a medical literature data base was performed for articles that discuss treatment for EoE. Results: A comparison of current therapies showed that dietary elimination, swallowed topical corticosteroids, and proton-pump inhibitor therapy are all effective for different populations. Emerging therapies that were reviewed include new topical corticosteroids and biologics directed against Type 2 inflammation. Conclusion: EoE is a chronic inflammatory disorder that can be debilitating, with long-term sequelae. There are no current approved therapies in the United States. Numerous new treatments are on the horizon. Increasing amounts of data are helping to tailor treatment for each patient. Ultimately, shared decision-making is the best approach to guide treatment choices with patients to manage the ever-increasing burden of this disease.

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.

IIB or not IIB, part 2: assessing inter-rater and intra-rater repeatability of the Kenney-Doig scale in equine endometrial biopsy evaluation

Inter- and intra-rater variability negatively affects the reliability of various histopathology grading scales used as prognostic aids in human and veterinary medicine. The Kenney-Doig categorization (grading) scale, which is used to associate equine endometrial histologic lesions with prognostic estimation of a broodmare's reproductive potential, has not been evaluated for inter- or intra-rater variability, to our knowledge. To assess whether the Kenney-Doig system produces reliable results among observers, 8 pathologists, all with American College of Veterinary Pathologists certification, were recruited to blindly categorize the same set of 63 digital equine endometrial biopsy slides as well as to re-evaluate anonymously 21 of 63 of these slides at a later time. Cohen kappa values for pairwise comparison of final Kenney-Doig categories were -0.05 to 0.46 (unweighted) and 0.08-0.64 (weighted), with an average Light kappa of 0.19 (unweighted) and 0.36 (weighted) across all 8 pathologists, 0.14 (unweighted) and 0.33 (weighted) for pathologists at different institutions, and 0.22 (unweighted) and 0.46 (weighted) for pathologists at the same institution. Intra-class correlations measuring intra-rater agreement were 0.12-0.77 with an average of 0.55 for all 8 pathologists. We found that only slight-to-moderate inter-rater agreement and poor-to-good intra-rater agreement was produced by 8 pathologists using the Kenney-Doig scale, suggesting that the system is subject to significant observer variability and care should be taken when communicating Kenney-Doig categories to submitting clinicians with emphasis on the quality of endometrial lesions present instead of the category and associated expected foaling rate.

Development and Validation of Web-Based Tool to Predict Lamina Propria Fibrosis in Eosinophilic Esophagitis

INTRODUCTION

Approximately half of esophageal biopsies from patients with eosinophilic esophagitis (EoE) contain inadequate lamina propria, making it impossible to determine the lamina propria fibrosis (LPF). This study aimed to develop and validate a web-based tool to predict LPF in esophageal biopsies with inadequate lamina propria.

METHODS

Prospectively collected demographic and clinical data and scores for 7 relevant EoE histology scoring system epithelial features from patients with EoE participating in the Consortium of Eosinophilic Gastrointestinal Disease Researchers observational study were used to build the models. Using the least absolute shrinkage and selection operator method, variables strongly associated with LPF were identified. Logistic regression was used to develop models to predict grade and stage of LPF. The grade model was validated using an independent data set.

RESULTS

Of 284 patients in the discovery data set, median age (quartiles) was 16 (8-31) years, 68.7% were male patients, and 93.4% were White. Age of the patient, basal zone hyperplasia, dyskeratotic epithelial cells, and surface epithelial alteration were associated with presence of LPF. The area under the receiver operating characteristic curve for the grade model was 0.84 (95% confidence interval: 0.80-0.89) and for stage model was 0.79 (95% confidence interval: 0.74-0.84). Our grade model had 82% accuracy in predicting the presence of LPF in an external validation data set.

DISCUSSION

We developed parsimonious models (grade and stage) to predict presence of LPF in esophageal biopsies with inadequate lamina propria and validated our grade model. Our predictive models can be easily used in the clinical setting to include LPF in clinical decisions and determine its effect on treatment outcomes.

Responsiveness of a Histologic Scoring System Compared With Peak Eosinophil Count in Eosinophilic Esophagitis

INTRODUCTION

The optimal instrument for assessing histologic disease activity in patients with eosinophilic esophagitis (EoE) is unclear. We assessed the responsiveness of the EoE Histologic Scoring System (EoE-HSS) when compared with that of the peak eosinophil count (PEC).

METHODS

Histopathology slides were obtained from patients with EoE at baseline and after 8 weeks of treatment with swallowed topical budesonide or elimination diet. Two blinded gastrointestinal pathologists scored biopsies on the EoE-HSS, PEC, and 100-mm visual analog scale (VAS) of overall histologic severity. Change was defined as an improvement by ≥0.5 SD in baseline VAS. Responsiveness was quantified using the standardized effect size (SES) and the probability that the index distinguishes a patient with improvement from a patient without improvement, which is the area under the receiver operating characteristic curve (AUC). Longitudinal validity was assessed using Pearson correlations between changes in EoE-HSS and both PEC and VAS.

RESULTS

The EoE-HSS grade (SES 2.18 [95% confidence interval, CI: 1.46-2.88]; AUC 0.73 [95% CI: 0.57-0.84]) and stage (SES 2.07 [95% CI: 1.37-2.77]; AUC 0.73 [95% CI: 0.58-0.84]) were highly responsive, similar to PEC (SES 1.44 [95% CI: 0.80-2.07]; AUC 0.73 [95% CI: 0.58-0.84]). The EoE-HSS grade and stage were more highly correlated with changes in VAS (grade 0.92 [95% CI: 0.86-0.95]; stage 0.89 [95% CI: 0.81-0.94]) than with changes in PEC (grade 0.74 [95% CI: 0.58-0.85]; stage 0.66 [95% CI: 0.47-0.80]).

DISCUSSION

The EoE-HSS is highly responsive, performs similarly to PEC, and is better correlated with changes in overall histologic activity in patients with EoE.

Development of a core outcome set for therapeutic studies in eosinophilic esophagitis (COREOS)

BACKGROUND

End points used to determine treatment efficacy in eosinophilic esophagitis (EoE) have evolved over time. With multiple novel therapies in development for EoE, harmonization of outcomes measures will facilitate evidence synthesis and appraisal when comparing different treatments.

OBJECTIVE

We sought to develop a core outcome set (COS) for controlled and observational studies of pharmacologic and diet interventions in adult and pediatric patients with EoE.

METHODS

Candidate outcomes were generated from systematic literature reviews and patient engagement interviews and surveys. Consensus was established using an iterative Delphi process, with items voted on using a 9-point Likert scale and with feedback from other participants to allow score refinement. Consensus meetings were held to ratify the outcome domains of importance and the core outcome measures. Stakeholders were recruited internationally and included adult and pediatric gastroenterologists, allergists, dieticians, pathologists, psychologists, researchers, and methodologists.

RESULTS

The COS consists of 4 outcome domains for controlled and observational studies: histopathology, endoscopy, patient-reported symptoms, and EoE-specific quality of life. A total of 69 stakeholders (response rate 95.8%) prioritized 42 outcomes in a 2-round Delphi process, and the final ratification meeting generated consensus on 33 outcome measures. These included measurement of the peak eosinophil count, Eosinophilic Esophagitis Histology Scoring System, Eosinophilic Esophagitis Endoscopic Reference Score, and patient-reported measures of dysphagia and quality of life.

CONCLUSIONS

This interdisciplinary collaboration involving global stakeholders has produced a COS that can be applied to adult and pediatric studies of pharmacologic and diet therapies for EoE and will facilitate meaningful treatment comparisons and improve the quality of data synthesis.

Intra- and interobserver agreement of histopathological findings in pediatric patients with eosinophilic esophagitis

OBJECTIVE

To assess intra- and interobserver agreement among non-expert pathologists in identifying features of the eosinophilic esophagitis histologic scoring system (EoEHSS) in pediatric patients.

PATIENTS AND METHODS

The authors used 50 slides from patients (aged 1-15 years; 72% male) with EoE. EoEHSS evaluates eosinophilic inflammation and other features including epithelial basal zone hyperplasia, eosinophilic abscesses, eosinophil surface layering, dilated intercellular spaces, surface epithelial alteration, dyskeratotic epithelial cells, and lamina propria fibrosis. Grade and stage of abnormalities are scored using a 4-point scale (0 normal; 3 maximum change). Four pathologists determined EoEHSS findings on two occasions. Intra- and interobserver agreement was assessed using Kappa (κ) statistics and intra-class correlation coefficients.

RESULTS

Intra- and interobserver agreement for the identification of eosinophil counts ≥ 15/high power field (HPF) was excellent, however varied when assessing additional features of the EoEHSS. For the more experienced pathologist, agreement for most EoEHSS items and the composite scores was substantial to excellent. For the less experienced pathologists, intraobserver agreement ranged from absent to substantial for individual features and ranged from moderate to substantial for the composite scores.

CONCLUSION

Most items of the EoEHSS had substantial to excellent reliability when assessed by a pathologist experienced in the diagnosis of EoE but presented lower repeatability among less experienced pathologists. These findings suggest that specific training of pathologists is required for the identification of EoEHSS characteristics beyond eosinophil count, as these features are considered useful in the evaluation of response to treatment and correlation with clinical manifestations and endoscopic findings.

Development and technical validation of an artificial intelligence model for quantitative analysis of histopathologic features of eosinophilic esophagitis

Background

In an attempt to provide quantitative, reproducible, and standardized analyses in cases of eosinophilic esophagitis (EoE), we have developed an artificial intelligence (AI) digital pathology model for the evaluation of histologic features in the EoE/esophageal eosinophilia spectrum. Here, we describe the development and technical validation of this novel AI tool.

Methods

A total of 10 726 objects and 56.2 mm² of semantic segmentation areas were annotated on whole-slide images, utilizing a cloud-based, deep learning artificial intelligence platform (Aiforia Technologies, Helsinki, Finland). Our training set consisted of 40 carefully selected digitized esophageal biopsy slides which contained the full spectrum of changes typically seen in the setting of esophageal eosinophilia, ranging from normal mucosa to severe abnormalities with regard to each specific features included in our model. A subset of cases was reserved as independent “test sets” in order to assess the validity of the AI model outside the training set. Five specialized experienced gastrointestinal pathologists scored each feature blindly and independently of each other and of AI model results.

Results

The performance of the AI model for all cell type features was similar/non-inferior to that of our group of GI pathologists (F1-scores: 94.5–94.8 for AI vs human and 92.6–96.0 for human vs human). Segmentation area features were rated for accuracy using the following scale: 1. “perfect or nearly perfect” (95%–100%, no significant errors), 2. “very good” (80%–95%, only minor errors), 3. “good” (70%–80%, significant errors but still captures the feature well), 4. “insufficient” (less than 70%, significant errors compromising feature recognition). Rating scores for tissue (1.01), spongiosis (1.15), basal layer (1.05), surface layer (1.04), lamina propria (1.15), and collagen (1.11) were in the “very good” to “perfect or nearly perfect” range, while degranulation (2.23) was rated between “good” and “very good”.

Conclusion

Our newly developed AI-based tool showed an excellent performance (non-inferior to a group of experienced GI pathologists) for the recognition of various histologic features in the EoE/esophageal mucosal eosinophilia spectrum. This tool represents an important step in creating an accurate and reproducible method for semi-automated quantitative analysis to be used in the evaluation of esophageal biopsies in this clinical context.

Eosinophilic Esophagitis: Incidence, Diagnosis, Management, and Future Directions

Eosinophilic esophagitis (EoE) is an antigen-mediated esophageal disease defined by the presence of esophageal eosinophilia and symptoms of esophageal dysfunction. The pathophysiology involves an allergen-driven Th2 T cell response that triggers infiltration of eosinophils into the esophagus leading to inflammation, remodeling, and fibrosis. This results in disruption of esophageal function and accompanying symptoms - most notably dysphagia. Effective therapies target inflammation or fibrostenotic complications and include proton pump inhibitors, swallowed topical steroids, dietary exclusion, and dilation. Clinical trials testing promising biologic therapies are ongoing.

Immunogenetic, Molecular and Microbiotic Determinants of Eosinophilic Esophagitis and Clinical Practice-A New Perspective of an Old Disease

Eosinophilic oesophagitis (EoE) is a chronic, allergic disease associated with a T-lymphocyte response inducing esophageal eosinophilic infiltration in the esophagus. Inflammation and tissue fibrosis are responsible for the main clinical symptoms such as food impaction and dysphagia. The etiopathogenesis is multifactorial in which genetic and environmental factors coexist. The most common trigger is a non-IgE-mediated food allergy to milk, wheat, egg, soybean, nuts, fish, and seafood. The second factor we focus on is the contribution of genetic variation to the risk of EoE, describing the expression profile of selected genes associated with eosinophilic oesophagitis. We raise the topic of treatment, aiming to eliminate inflammation through an elimination diet and/or use of pharmacologic therapy with the use of proton pump inhibitors or steroids and endoscopic procedures to dilate the esophagus. We demonstrate that early diagnosis and effective treatment prevent the development of food impaction and decreased quality of life. The increasing presence of EoE requires bigger awareness among medical specialists concerning clinical features, the course of EoE, diagnostic tools, and management strategies.

Usefulness of the Eosinophilic Esophagitis Histologic Scoring System in Distinguishing Active Eosinophilic Esophagitis From Remission and Gastroesophageal Reflux Disease

Background

Eosinophilic esophagitis (EoE) is defined as esophageal dysfunction in the presence of > 15 intraepithelial eosinophils per high-power field (eos/hpf) in either the mid or distal esophagus. The current focus of EoE pathologic evaluation is the peak eosinophil count (PEC), although histologic features other than eosinophilic inflammation are also commonly observed. In addition, histologic variance between the mid and distal esophagus in EoE has not been rigorously studied. The aim of our study was to utilize a recently developed EoE histologic scoring system (EoEHSS) to compare the mid and the distal esophageal histology in patients with active EoE (EoE-A), EoE in remission (EoE-R), and gastroesophageal reflux disease (GERD).

Methods

EoEHSS was used to prospectively evaluate the severity and extent of changes in multiple histopathologic features (PEC; basal zone hyperplasia (BZH); eosinophilic abscesses (EA); eosinophil surface layering (ESL); dilated intercellular spaces (DIS); surface epithelial alteration (SEA); dyskeratotic epithelial cells (DEC); lamina propria fibrosis (LPF)) in the mid and distal esophageal biopsies in 85 pediatric patients at a tertiary medical center. These patients were divided into three cohorts: EoE-A (n = 36), EoE-R (n = 12) and GERD (n = 37).

Results

Total grade (severity) and stage (extent) scores were significantly higher in EoE-A compared to EoE-R and GERD patients in both the mid and the distal esophagus. The mean total grade scores in the mid esophagus, but not the distal esophagus remained higher in EoE-R as compared to GERD patients. Specific histopathologic features independent of PEC were different in distal and mid esophagus in EoE-A. About one-half of children with active EoE had different EoEHSS scores in their mid and distal esophageal biopsies.

Conclusions

EoEHSS yields histologic insights beyond those derived from PEC and helps in more objective, reproducible and accurate diagnosis of EoE and GERD. It also provides a more comprehensive understanding into the pathophysiology of EoE.

Targeted Therapies for Eosinophilic Gastrointestinal Disorders

The growing recognition of eosinophilic gastrointestinal disorders has revealed the limitations of current treatment (mainly based on dietary modification and corticosteroids), and include refractoriness, high recurrence rates, and the need for long-term therapy. Research efforts, mainly in eosinophilic esophagitis (EoE), have unveiled essential pathophysiological mechanisms leading to these disorders, which bear some similarities to those of atopic manifestations and are shared by eosinophilic gastroenteritis (EGE) and eosinophilic colitis (EC). Novel targeted therapies, some imported from bronchial asthma and atopic dermatitis, are currently being assessed in EoE. The most promising are monoclonal antibodies, including those targeting interleukin (IL)-13 (cendakimab) and IL-4 (dupilumab), with phase 3 trials currently ongoing. The potential of anti-integrin therapy (vedolizumab) and Siglec-8 blockers (antolimab) in EGE are also promising. Non-biological therapies for eosinophilic gut disorders, which include preventing the activation of Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and chemoattractant receptor expressed on T helper 2 cells (CRTH2) signaling pathways, and other potential targets that deserve investigation in eosinophilic gut disorders, are reviewed.

Image Analysis of Eosinophil Peroxidase Immunohistochemistry for Diagnosis of Eosinophilic Esophagitis

BACKGROUND

Diagnosis of eosinophilic esophagitis (EoE) requires manual quantification of tissue eosinophils. Eosinophil peroxidase (EPX) is an eosinophil-specific, cytoplasmic granule protein released during degranulation.

AIMS

The objective of this study was to evaluate image analysis of EPX immunohistochemistry as an automated method for histologic diagnosis of EoE.

METHODS

We performed a secondary analysis of prospectively collected esophageal biopsies obtained from adult subjects with EoE and controls. Tissue sections were stained with hematoxylin and eosin (H&E) and evaluated for peak eosinophils per high power field (eos/hpf). The same slides were de-stained and re-stained to detect EPX for direct comparison. Slides were digitized, and EPX staining area/mm² was quantified using image analysis. Paired samples were compared for changes in EPX staining in treatment responders and non-responders.

RESULTS

Thirty-eight EoE cases and 49 controls were analyzed. Among EoE subjects, matched post-treatment biopsies were available for 21 responders and 10 non-responders. Baseline EPX/mm² was significantly increased in EoE subjects and decreased in treatment responders. EPX quantification correlated strongly with eos/hpf (r = 0.84, p < 0.0001) and identified EoE subjects with high diagnostic accuracy (AUC 0.95, p < 0.0001). The optimal diagnostic EPX-positive pixel/area threshold was 17,379 EPX/mm². Several controls (5/49) with < 15 eos/hpf on H&E staining exceeded this cutoff.

CONCLUSIONS

EPX/mm² correlates strongly with eos/hpf, accurately identifies subjects with EoE, and decreases in treatment responders. Automated quantification of intact eosinophils and their degranulation products may enhance pathologic assessment. Future studies are needed to correlate EPX/mm² with symptoms, endoscopic findings, and esophageal distensibility.

Long-term Efficacy and Tolerability of RPC4046 in an Open-Label Extension Trial of Patients With Eosinophilic Esophagitis

BACKGROUND & AIMS

The short-term efficacy of RPC4046, a monoclonal antibody against interleukin-13, has been shown in patients with eosinophilic esophagitis (EoE). We investigated the long-term efficacy and safety of RPC4046 in an open-label, long-term extension (LTE) study in adults with EoE.

METHODS

We analyzed data from 66 patients who completed the 16-week, double-blind, induction portion of a phase 2 study of RPC4046 (180 mg or 360 mg/wk) vs placebo and then completed a 52-week LTE, receiving open-label RPC4046 360 mg/wk. The study was conducted at 28 centers in 3 countries; patients were enrolled between September 2014 and January 2017. Outcomes were stratified by double-blind dose group and included esophageal eosinophil counts, EoE endoscopic reference score, EoE histologic scoring system score, symptom-based EoE activity index score, and safety.

RESULTS

By week 12 of the LTE, esophageal eosinophil mean and peak counts, total EoE endoscopic reference scores, and EoE histologic scoring system grade and stage scores did not differ considerably between patients who originally received placebo vs RPC4046. Most patients maintained responses through week 52. Symptom remission (symptom-based EoE activity index score, ≤20) increased from 14% at LTE entry to 67% at LTE week 52 in placebo‒RPC4046 patients and from 30% to 54% in RPC4046‒RPC4046 (either dose) patients. Of the 28 patients who did not have a histologic response to RPC4046 during the double-blind induction phase, 10 patients (36%) achieved response during the LTE. The most common adverse events were upper respiratory tract infection (21%) and nasopharyngitis (14%).

CONCLUSIONS

One year of treatment with RPC4046 is generally well tolerated and results in continued improvement and/or maintenance of endoscopic, histologic, and clinical measures of EoE disease activity relative to baseline.

TRIAL REGISTRATION

NCT02098473.

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

Endoscopy plays an important role in the management of eosinophilic esophagitis (EoE), since it is involved in the diagnosis, follow-up and treatment of this condition. In patients presenting with food impaction, dysphagia and other symptoms of suspected EoE, esophago-gastric-duodenoscopy (EGD) with multiple esophageal biopsies should be performed to confirm or rule out the diagnosis of EoE. The EREFS system, a validated instrument for assessment of the endoscopically-identified esophageal features in EoE (edema, rings, exudates, longitudinal furrows and strictures), is currently used in the clinical practice for the evaluation of the macroscopic aspects of esophageal mucosa during EGD. Multiple esophageal biopsies are mandatory to further confirm EoE diagnosis and subsequent response to treatment, since symptoms reported by patients do not always correlate with histological activity, and considering the low sensitivity of endoscopic assessment; a cut-off of ≥15 eosinophils in at least one high power field is the density threshold considered the standard for diagnosis (sensitivity 100%, specificity 96%). Other histological features, included in the EoE histologic scoring system (EoEHSS), are supportive for the diagnosis and for the assessment of inflammatory activity during follow-up. Esophageal dilation, performed either with Savary dilators/bougie or hydrostatic balloon, is an effective and safe treatment in both adult and pediatric EoE patients with fibrostenotic features, mainly in association with other therapeutic strategies which can control eosinophilic inflammation.

Red Between the Lines: Evolution of Eosinophilic Esophagitis as a Distinct Clinicopathologic Syndrome

Eosinophilic esophagitis (EoE) is characterized by eosinophilic infiltration of the esophageal mucosa and symptoms of esophageal dysfunction, including dysphagia. While EoE is still considered a rare disease, in practice it seems that more and more cases are diagnosed every week, research in the field is exploding, and the pipeline for treatments contains multiple agents, some of which are quite far along the development pathway. After only scattered cases and small series were published in the late 1970s and 1980, Stephen Attwood, Thomas Smyrk, Tom DeMeester, and James Jones, published in Digestive Diseases and Sciences in 1993 a seminal report that described a clinicopathologic syndrome of esophageal eosinophilia with dysphagia. This review details the origins of this paper and compares and contrast what was observed then and what is known now about multiple aspects of EoE, including the clinical presentation, diagnosis, epidemiology, natural history, and treatments and outcomes. Moreover, it will highlight how the paper presaged a number of controversies in the field that have yet to be resolved, as well as foreshadowed the collaborative, multidisciplinary approach that has led to rapid advances.

Eosinophilic esophagitis: updates on key unanswered questions

Eosinophilic esophagitis (EoE) is a clinicopathologic disease characterized by symptoms of esophageal dysfunction and esophageal eosinophilia. In the last decade, there has been a dramatic increase in its prevalence for reasons that are not completely understood. The underlying pathophysiology involves an antigen-mediated T_H 2 immune response that draws eosinophils to the esophagus, causing mucosal inflammation, esophageal remodeling, and fibrosis. This ultimately leads to esophageal dysfunction that most commonly manifests as dysphagia. In this review, we will discuss updates on key questions regarding the diagnosis and treatment of EoE.

Daily Dilemmas in Pediatric Gastrointestinal Pathology

The evaluation of gastrointestinal pathology in children often requires a different approach from that in adults. In this concise review, the authors outline 3 diagnostic challenges that are often encountered in daily practice; these include eosinophilic diseases, duodenal intraepithelial lymphocytosis with preserved villous architecture, and terminal ileal inflammation in the setting of idiopathic inflammatory bowel disease.

Persistent Basal Cell Hyperplasia Is Associated With Clinical and Endoscopic Findings in Patients With Histologically Inactive Eosinophilic Esophagitis

BACKGROUND & AIMS

Although eosinophil count is the standard used to monitor disease activity in patients with eosinophilic esophagitis (EoE), there are often disparities between patient-reported symptoms and eosinophil counts. We examined the prevalence of epithelial alterations, namely basal cell hyperplasia (BCH) and spongiosis, among patients with inactive EoE (eosinophil counts below 15 following therapy) and aimed to determine whether maintenance of these changes in epithelial morphology are associated with persistent clinical findings.

METHODS

Esophageal biopsies of 243 patients (mean age, 16.9 years) undergoing routine endoscopy at the University of Pennsylvania were evaluated for epithelial BCH and spongiosis. Univariable analysis was used to calculate the association between epithelial changes and symptoms as well as endoscopic findings and peak eosinophil count. We validated our findings using data from a cohort of patients at the University of North Carolina.

RESULTS

The discovery and validation cohorts each included patients with inactive EoE, based on histologic factors, but ongoing BCH and spongiosis. Ongoing BCH, but not spongiosis, in patients with inactive EoE was associated with symptoms (odds ratio, 2.14; 95% CI, 1.03-4.42; P = .041) and endoscopic findings (odds ratio, 7.10; 95% CI, 3.12-16.18; P < .001).

CONCLUSIONS

In patients with EoE, the presence of BCH might indicate ongoing disease activity, independent of eosinophil count. This might account for the persistent symptoms in patients who are considered to be in remission based on histologic factors.

Eosinophilic Esophagitis Histology Remission Score: Significant Relations to Measures of Disease Activity and Symptoms

OBJECTIVES

Eosinophilic esophagitis (EoE) is characterized by remissions and relapses. Guidelines defining remission do not exist and therefore remission is inconsistently identified. We sought to define histology remission in EoE.

METHODS

Esophageal biopsies, obtained at the time the validated pediatric EoE symptoms scores v2.0 (PEESS v2.0) questionnaire was completed (N = 42), were scored using the validated EoE Histology Scoring System. An EoE Histology Remission Score (EoEHRS) was constructed and specified that in all esophageal sites sampled the peak eosinophil count was <15 per high power field (HPF); in addition, neither the total grade (severity of pathology) nor stage (extent of pathology) scores could exceed 3 (possible total maximum score for each was 24). Spearman correlation coefficients were generated for histology/symptom correlations; coefficient range 0.31 to 0.50 was considered moderate.

RESULTS

EoE Histology Scoring System composite and individual feature scores from proximal and distal esophageal biopsies correlated moderately with PEESS v2.0 mean scores (0.48-0.36, P < 0.01), and with scores in the dysphagia (0.39-0.30, P ≤ 0.01), pain (0.48-0.34, P ≤ 0.01), and gastroesophageal reflux disease (0.51-0.32, P ≤ 0.01) domains. Biopsies that met full EoEHRS criteria had reduced biomarkers, specifically expression of the mast cell markers CPA3 and tryptase mRNA, and reduced eosinophil peroxidase deposition (P < 0.03), compared to those with nonremission scores. Subjects whose biopsies met EoEHRS remission criteria reported reduced symptoms for all domains except nausea and vomiting (P ≤ 0.01).

CONCLUSIONS

The EoEHRS correlated with reduced biomarkers of disease activity and reduced symptoms, and therefore may be useful to inform clinical care and interstudy comparisons.

Budesonide Oral Suspension Significantly Improves Eosinophilic Esophagitis Histology Scoring System Results: Analyses From a 12-Week, Phase 2, Randomized, Placebo-controlled Trial

Budesonide oral suspension (BOS) is a novel topical corticosteroid, which has been shown to improve symptoms and endoscopic appearance, and reduce peak eosinophil counts in patients with eosinophilic esophagitis (EoE). This trial evaluated the effect of BOS or placebo on the severity (grade) and extent (stage) of 8 histopathologic features observed in EoE, using the validated eosinophilic esophagitis histologic scoring system (EoE HSS). Patients with EoE aged 11 to 40 years with dysphagia were randomized to receive either BOS (2.0 mg twice daily) or placebo for 12 weeks. Mean (SD) EoE HSS grade and stage total scores at baseline for placebo and BOS groups were: grade, 0.42 (0.16) and 0.49 (0.14), respectively; stage: 0.38 (0.14) and 0.46 (0.11), respectively. These scores significantly decreased (improved) from baseline for patients receiving BOS versus placebo (grade: least squares mean change [SE]: placebo vs. BOS, -0.04 [0.03] vs. -0.24 [0.02]; P<0.0001; stage: -0.01 [0.02] vs. -0.19 [0.02]; P<0.0001). EoE HSS total scores improved for 6 of the 8 and 5 of the 8 histopathologic features for grade and stage, respectively, versus placebo. Change in EoE HSS total scores correlated moderately but significantly with change in endoscopic severity (endoscopic reference score; grade: R=0.5349; stage: R=0.5416; both P<0.0001). Change in EoE HSS stage total score correlated weakly with change in Dysphagia Symptom Questionnaire scores (grade: R=0.1925; P=0.0740; stage: R=0.2135; P=0.0471). These data demonstrate that the EoE HSS is a valuable endpoint of treatment response in randomized clinical trials and should be considered for future trials for EoE.

Eosinophilic esophagitis: imaging features with endoscopic and pathologic correlation

OBJECTIVE

We aim to review the imaging features of eosinophilic esophagitis on fluoroscopy and present how they can correlate with endoscopic and pathologic findings.

RESULTS

Eosinophilic esophagitis is a chronic immune-mediated disease that results in esophageal dysfunction. Upper esophagogastroduodenoscopy is high yield and required for biopsies to demonstrate the hallmark histologic findings of eosinophil-predominant inflammation. While esophagogastroduodenoscopy is currently mandatory for diagnosis, imaging findings can provide valuable information regarding the structural and functional properties of the esophagus. In addition, fluoroscopic studies may be very helpful in the setting of subtle findings and to evaluate fibrotic remodeling changes.

CONCLUSION

Radiologic examinations are a valuable tool in the assessment of eosinophilic esophagitis and can highlight changes of fibrostenotic disease, as overall narrowing can be more conspicuous fluoroscopically than endoscopically. As the disease increases in prevalence, it is critical that physicians recognize this condition and facilitate diagnosis and treatment.

Pharmacological treatments for eosinophilic esophagitis: current options and emerging therapies

Introduction: The epidemiology of eosinophilic esophagitis (EoE) has increased rapidly to represent a common cause of chronic and recurrent esophageal symptoms. Current treatment options have limitations so the development of novel therapies is a matter of growing interest.Areas covered: This article provides an up-to-date discussion of current therapies and investigational options for EoE. Established anti-inflammatory treatments for EoE at present include dietary therapy, proton pump inhibitors and swallowed topic steroids, which should be combined with endoscopic dilation in case of strictures. Refractoriness, high recurrence rates, and need for long-term therapies have promoted the investigation of novel, esophageal-targeted formulas of topic corticosteroids, and monoclonal antibodies (including mepolizumab, reslizumab, QAX576, RPC4046, dupilumab, omalizumab, infliximab, and vedolizumab) for EoE, with some having been demonstrated as effective and safe in the short term. Several additional promising therapies are also discussed.Expert opinion: Several therapeutic targets have shown efficacy and will be approved to treat EoE, especially corticosteroid-sparing options and those for patients with multiple Th2-associated diseases. Personalized therapeutic strategies for initial and maintenance treatments of EoE must be rationally designed, to reduce the burden of disease and answer meaningfully the needs of all stakeholders involved in EoE.

Efficacy of Dupilumab in a Phase 2 Randomized Trial of Adults With Active Eosinophilic Esophagitis

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is an allergen-mediated inflammatory disease with no approved treatment in the United States. Dupilumab, a VelocImmune-derived human monoclonal antibody against the interleukin (IL) 4 receptor, inhibits IL4 and IL13 signaling. Dupilumab is effective in the treatment of allergic, atopic, and type 2 diseases, so we assessed its efficacy and safety in patients with EoE.

METHODS

We performed a phase 2 study of adults with active EoE (2 episodes of dysphagia/week with peak esophageal eosinophil density of 15 or more eosinophils per high-power field), from May 12, 2015, through November 9, 2016, at 14 sites. Participants were randomly assigned to groups that received weekly subcutaneous injections of dupilumab (300 mg, n = 23) or placebo (n = 24) for 12 weeks. The primary endpoint was change from baseline to week 10 in Straumann Dysphagia Instrument (SDI) patient-reported outcome (PRO) score. We also assessed histologic features of EoE (peak esophageal intraepithelial eosinophil count and EoE histologic scores), endoscopically visualized features (endoscopic reference score), esophageal distensibility, and safety.

RESULTS

The mean SDI PRO score was 6.4 when the study began. In the dupilumab group, SDI PRO scores were reduced by a mean value of 3.0 at week 10 compared with a mean reduction of 1.3 in the placebo group (P = .0304). At week 12, dupilumab reduced the peak esophageal intraepithelial eosinophil count by a mean 86.8 eosinophils per high-power field (reduction of 107.1%; P < .0001 vs placebo), the EoE-histologic scoring system (HSS) severity score by 68.3% (P < .0001 vs placebo), and the endoscopic reference score by 1.6 (P = .0006 vs placebo). Dupilumab increased esophageal distensibility by 18% vs placebo (P < .0001). Higher proportions of patients in the dupilumab group developed injection-site erythema (35% vs 8% in the placebo group) and nasopharyngitis (17% vs 4% in the placebo group).

CONCLUSIONS

In a phase 2 trial of patients with active EoE, dupilumab reduced dysphagia, histologic features of disease (including eosinophilic infiltration and a marker of type 2 inflammation), and abnormal endoscopic features compared with placebo. Dupilumab increased esophageal distensibility and was generally well tolerated. ClinicalTrials.gov, Number: NCT02379052.

Oesophageal eosinophilia and oesophageal diseases in children: are the limits clear?

Gastro-oesophageal reflux disease, eosinophilic oesophagitis and oesophageal motility disorders are among the most common diseases accompanying oesophageal eosinophilia. They have similarities and their limits are frequently not well defined. This article reviews the main characteristics relating to their similarities and differences, highlighting existing controversies among these diseases, in addition to current knowledge. In the case of a patient with symptoms of oesophageal dysfunction, it is suggested to carry out an integral analysis of the clinical features and diagnostic test results, including histology, while individualising each case before confirming a definitive diagnosis. Future investigation in paediatric patients is necessary to assess eosinophilic infiltration in the various layers of the oesophageal tissue, along with its clinical and pathophysiological implications.

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTIONS

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

RESULTS

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

CONCLUSION

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

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.

RPC4046, a Monoclonal Antibody Against IL13, Reduces Histologic and Endoscopic Activity in Patients With Eosinophilic Esophagitis

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is a chronic, esophageal, type 2 inflammatory response associated with increased serum levels of interleukin 13 (IL13), which might contribute to its pathogenesis. RPC4046, a recombinant humanized monoclonal antibody against IL13, prevents its binding to the receptor subunits IL13RA1 and IL13RA2. We performed a phase 2 trial to evaluate the efficacy and safety of RPC4046 in patients with EoE.

METHODS

We performed a multicenter, double-blind trial of 99 adults with active EoE randomly assigned (1:1:1) to groups given RPC4046 (180 or 360 mg) or placebo once weekly for 16 weeks, from September 2014 through December 2015. Patients were seen at day 1 (baseline) and weeks 2, 4, 8, 12, and 16. They underwent esophagogastroduodenoscopy and biopsies were collected at baseline and week 16. Patients completed a daily dysphagia symptom diary through week 16 and patient-reported outcome data were collected. The primary outcome was change in mean esophageal eosinophil count in the 5 high-power fields (hpfs) with the highest level of inflammation.

RESULTS

At week 16, mean changes in esophageal eosinophil count per hpf were a reduction of 94.8 ± 67.3 in patients who received 180 mg RPC4046 (P < .0001) and a reduction of 99.9 ± 79.5 in patients who received 360 mg RPC4046 (P < .0001) compared with a reduction of 4.4 ± 59.9 in patients who received placebo. The 360-mg RPC4046 group, compared with the placebo group, showed significant reductions in validated endoscopic severity score at all esophageal locations (P < .0001), validated histologic grade and stage scores (both P < .0001), and clinician's global assessment of disease severity (P = .0352); they had a numerical reduction in scores from the dysphagia symptom diary (P = .0733). Significant reductions in esophageal eosinophil counts and histologic and endoscopic features were observed in patients with steroid-refractory EoE who received RPC4046. The most common adverse events were headache and upper respiratory tract infection.

CONCLUSIONS

In a phase 2 trial of patients with EoE, we found RPC4046 (a monoclonal antibody against IL13) to reduce histologic and endoscopic features compared with placebo. RPC4046 was well tolerated. ClinicalTrials.gov no: NCT02098473.

Baseline Gastrointestinal Eosinophilia Is Common in Oral Immunotherapy Subjects With IgE-Mediated Peanut Allergy

Rationale: Oral immunotherapy (OIT) is an emerging treatment for food allergy. While desensitization is achieved in most subjects, many experience gastrointestinal symptoms and few develop eosinophilic gastrointestinal disease. It is unclear whether these subjects have subclinical gastrointestinal eosinophilia (GE) at baseline. We aimed to evaluate the presence of GE in subjects with food allergy before peanut OIT.

Methods: We performed baseline esophagogastroduodenoscopies on 21 adults before undergoing peanut OIT. Subjects completed a detailed gastrointestinal symptom questionnaire. Endoscopic findings were assessed using the Eosinophilic Esophagitis (EoE) Endoscopic Reference Score (EREFS) and biopsies were obtained from the esophagus, gastric antrum, and duodenum. Esophageal biopsies were evaluated using the EoE Histologic Scoring System. Immunohistochemical staining for eosinophil peroxidase (EPX) was also performed. Hematoxylin and eosin and EPX stains of each biopsy were assessed for eosinophil density and EPX/mm² was quantified using automated image analysis.

Results: All subjects were asymptomatic. Pre-existing esophageal eosinophilia (>5 eosinophils per high-power field [eos/hpf]) was present in five participants (24%), three (14%) of whom had >15 eos/hpf associated with mild endoscopic findings (edema, linear furrowing, or rings; median EREFS = 0, IQR 0–0.25). Some subjects also demonstrated basal cell hyperplasia, dilated intercellular spaces, and lamina propria fibrosis. Increased eosinophils were noted in the gastric antrum (>12 eos/hpf) or duodenum (>26 eos/hpf) in 9 subjects (43%). EPX/mm² correlated strongly with eosinophil counts (r = 0.71, p < 0.0001).

Conclusions: Pre-existing GE is common in adults with IgE-mediated peanut allergy. Eosinophilic inflammation (EI) in these subjects may be accompanied by mild endoscopic and histologic findings. Longitudinal data collection during OIT is ongoing.