Clinical relevance of esophageal subepithelial activity in eosinophilic esophagitis

Esophageal remodeling in eosinophilic esophagitis

PURPOSE OF REVIEW

Eosinophilic esophagitis (EoE) is a Th2 immune/antigen-mediated disorder characterized by esophageal dysfunction and eosinophilic inflammation. Worsening dysphagia and food impactions are significant complications associated with esophageal remodeling and fibrostenotic disease. This review highlights the most recent research findings pertaining to mechanisms of sub-epithelial fibrosis in EoE, current diagnostic tools, and therapeutic approaches.

RECENT FINDINGS

Recent studies leveraging publicly available single cell sequencing databases and comparative proteomics have furthered our understanding of the mechanisms mediating fibrosis. Fibroblast crosstalk with the extracellular matrix and with epithelial, endothelial, and T cells have been implicated, with the likely existence of multiple fibroblast sub-types. Accurate diagnosis of remodeling with biopsies remains a challenge due to inadequate depth of sampling. Web-based tools incorporating epithelial findings show promise in predicting subepithelial fibrosis. Impedance planimetry with esophageal distensibility measurements are increasingly utilized tools to assess fibrostenotic severity. Immunostaining and luminal captured proteins associated with remodeling show promise as potential molecular markers of fibrosis. Anti-inflammatory therapy may improve esophageal fibrosis and distensibility, although specific fibrosis-targeted therapy is lacking.

SUMMARY

Recent studies highlight novel mechanisms of fibrosis in EoE. Improved understanding of these mechanisms may lead to novel diagnostic strategies and therapies, and thereby inform treatment decisions.

Clinical and molecular correlates of the Index of Severity for Eosinophilic Esophagitis

BACKGROUND

The Index of Severity for Eosinophilic Esophagitis (I-SEE) is a new expert-defined clinical tool that classifies disease severity of eosinophilic esophagitis (EoE).

OBJECTIVE

We aimed to determine whether I-SEE is associated with patient characteristics, molecular features of EoE, or both.

METHODS

We analyzed a prospective cohort of patients with EoE from the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR). Associations between I-SEE and clinical and molecular features (assessed by an EoE diagnostic panel [EDP]) were assessed.

RESULTS

In 318 patients with chronic EoE (209 adults, 109 children), median total I-SEE score was 7.0, with a higher symptoms and complications score in children than adults (4.0 vs 1.0; P < .001) and higher inflammatory and fibrostenotic features scores in adults than children (3.0 vs 1.0 and 3.0 vs 0, respectively; both P < .001). Total I-SEE score had a bimodal distribution with the inactive to moderate categories and severe category. EDP score correlated with total I-SEE score (r = -0.352, P < .001) and both inflammatory and fibrostenotic features scores (r = -0.665, P < .001; r = -0.446, P < .001, respectively), but not with symptoms and complications scores (r = 0.047, P = .408). Molecular severity increased from inactive to mild and moderate, but not severe, categories. Longitudinal changes of modified I-SEE scores and inflammatory and fibrostenotic features scores reflected histologic and molecular activity.

CONCLUSIONS

I-SEE score is associated with select clinical features across severity categories and with EoE molecular features for nonsevere categories, warranting further validation.

Eosinophilic esophagitis and duodenal food challenge - evaluation through endoscopic confocal laser endomicroscopy

BACKGROUND

Endoscopic confocal laser endomicroscopy (eCLE) is an established technique that allows clinical evaluation of mucosal integrity by fluorescein leaking through the mucosa upon duodenal food challenge (DFC). Analysis of eCLE with DFC in eosinophilic esophagitis (EoE) would be interesting to evaluate epithelial barrier dysfunction also in other regions of the gastrointestinal tract and to characterize potential individual food allergens that trigger the esophageal inflammation.

METHODS

In an observational and proof of concept study we evaluated 9 patients with histologically proven EoE by eCLE and DFC. Severity of symptoms were graduated according to the validated symptom-based EoE activity index. The endoscopic appearance of the esophagus was described according to the Endoscopic Reference Score System (ERERS). Spontaneous and food induced transfer of fluorescein into duodenal lumen were detected 10 minutes following intravenously application of fluorescein and 10 minutes after DFC. Food allergens were yeast, egg, soy, milk, and wheat, respectively. Local application of sodium chloride solution 10 % to the duodenal mucosa before DFC served as a control. Patients responding to DFC received a dietary exclusion therapy according to the results of DFC.

RESULTS

We investigated 9 patients with EoE (8 men, 49.7±13.8, 36-76 years). Symptom-based EoE activity index was 79±27.4, 33-100. In all patients EoE was confirmed by histology with number of esophageal mucosal eosinophilic granulocytes > 15/HPF, (91.4±77.4, 42-263). Mean ERERS score was 4.5±1.3, 3-7. None of the patients was aware of any food intolerance. eCLE revealed one patient with spontaneous transfer of i. v. fluorescein into duodenal lumen before DFC ("leaky gut"). 40 DFC were performed in the remaining 8 patients of whom 5 patients (61 %) responded to DFC. Rank order of fluorescein leakage upon DFC was wheat and milk in 37.5 % each, soy in 25 %, and egg in 12.5 %. The patients were treated by PPI (n=9), esophageal bouginage (n=5) and/or local corticoid therapy (n=3). The 5 patients responding to DFC received an additional food exclusion dietary advice focussed on the results of DFC. All patients reported a reduction of their symptoms. EoE activity indexes of patients with positive DFC were 73.7+28.6, 33-100 before and 22.7+37.9, 0-79 four weeks after food exclusion.

CONCLUSION

The findings of our proof of concept study suggest that eCLE with DFC may be an interesting tool to further evaluate patients with EoE. This technique has the potential to identify patients who may benefit from an additional individual dietary therapy.

The occurrence and development mechanisms of esophageal stricture: state of the art review

BACKGROUND

Esophageal strictures significantly impair patient quality of life and present a therapeutic challenge, particularly due to the high recurrence post-ESD/EMR. Current treatments manage symptoms rather than addressing the disease's etiology. This review concentrates on the mechanisms of esophageal stricture formation and recurrence, seeking to highlight areas for potential therapeutic intervention.

METHODS

A literature search was conducted through PUBMED using search terms: esophageal stricture, mucosal resection, submucosal dissection. Relevant articles were identified through manual review with reference lists reviewed for additional articles.

RESULTS

Preclinical studies and data from animal studies suggest that the mechanisms that may lead to esophageal stricture include overdifferentiation of fibroblasts, inflammatory response that is not healed in time, impaired epithelial barrier function, and multimethod factors leading to it. Dysfunction of the epithelial barrier may be the initiating mechanism for esophageal stricture. Achieving perfect in-epithelialization by tissue-engineered fabrication of cell patches has been shown to be effective in the treatment and prevention of esophageal strictures.

CONCLUSION

The development of esophageal stricture involves three stages: structural damage to the esophageal epithelial barrier (EEB), chronic inflammation, and severe fibrosis, in which dysfunction or damage to the EEB is the initiating mechanism leading to esophageal stricture. Re-epithelialization is essential for the treatment and prevention of esophageal stricture. This information will help clinicians or scientists to develop effective techniques to treat esophageal stricture in the future.

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.

Reproducibility and Generalizability of the Web-Based Tool to Predict Lamina Propria Fibrosis in Eosinophilic Esophagitis

We investigated reproducibility and generalizability of the recently developed web-based model to predict lamina propria fibrosis (LPF) in esophageal biopsies with inadequate lamina propria (LP) from patients with eosinophilic esophagitis (EoE) using an independent dataset (N = 183). For grade and stage scores of LPF, the area under the curve for predictive model was 0.77 (0.69-0.84) and 0.75 (0.67-0.82), and its accuracy was 78% and 72%, respectively. These model performance metrics were similar to that of the original model. A significant positive correlation was noted between the models' predictive probability and the grade and stage of LPF assessed by a pathologist (grade: r2 = 0.48, P < 0.001; and stage: r2 = 0.39, P < 0.001). These results support the reproducibility and generalizability of the web-based model to predict the presence of LPF in esophageal biopsies with inadequate LP in EoE. Additional studies are warranted to refine the web-based predictive models to provide predictive probability for sub-scores of LPF severity.

Increase in distal esophageal wall thickness with time in adult patients with eosinophilic esophagitis

Background and Aim

Eosinophilic esophagitis (EoE) is a chronic disease which may progress to a fibro-stenotic phenotype due to esophageal sub-epithelial fibrosis. Esophageal wall thickening in patients with EoE has been demonstrated in a few studies using endoscopic ultrasound (EUS). The aim of this study was to longitudinally assess the endoscopic appearance, wall thickness, histology, and dysphagia score of EoE patients.

Methods

Patients with EoE were recruited and studied between February 2012 and April 2021. Patients were evaluated on two separate occasions at least 12 months apart with endoscopy, EUS, and esophageal mucosal biopsies. The dysphagia score and epidemiology data were also assessed.

Results

A total of 16 EoE patients were included with a mean follow-up duration of 2.2 ± 1.2 years. In 14/16 (88%) patients, the total wall thickness of the distal esophagus significantly increased (P = 0.0012) as a result of thickening of the muscularis propria (P = 0.0218). However, only 1/14 (7%) patient had an increase in the dysphagia score, while 8/14 (57%) and 5/14 (36%) had a stable and reduced dysphagia score, respectively. No differences were found in the total thickness of other esophageal regions, dysphagia score, endoscopic appearance, and eosinophil count over time.

Conclusion

Distal esophageal wall thickness increases with time in EoE patients, independent of the dysphagia score and eosinophil count.

Endoscopic Diagnosis of Eosinophilic Esophagitis: Basics and Recent Advances

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated inflammatory disease, characterized by esophageal dysfunction and intense eosinophil infiltration localized in the esophagus. In recent decades, EoE has become a growing concern as a major cause of dysphagia and food impaction in adolescents and adults. EoE is a clinicopathological disease for which the histological demonstration of esophageal eosinophilia is essential for diagnosis. Therefore, the recognition of the characteristic endoscopic features with subsequent biopsy are critical for early definitive diagnosis and treatment, in order to prevent complications. Accumulating reports have revealed that EoE has several non-specific characteristic endoscopic findings, such as rings, furrows, white exudates, stricture/narrowing, edema, and crepe-paper esophagus. These findings were recently unified under the EoE endoscopic reference score (EREFS), which has been widely used as an objective, standard measurement for endoscopic EoE assessment. However, the diagnostic consistency of those findings among endoscopists is still inadequate, leading to underdiagnosis or misdiagnosis. Some endoscopic findings suggestive of EoE, such as multiple polypoid lesions, caterpillar sign, ankylosaurus back sign, and tug sign/pull sign, will aid the diagnosis. In addition, image-enhanced endoscopy represented by narrow band imaging, endocytoscopy, and artificial intelligence are expected to render endoscopic diagnosis more efficient and less invasive. This review focuses on suggestions for endoscopic assessment and biopsy, including recent advances in optical technology which may improve the diagnosis of EoE.

Disease Burden and Unmet Need in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic, progressive, type 2 inflammatory disease of increasing prevalence, characterized by symptoms of dysphagia and reduced quality of life. A dysregulated type 2 immune response to food and aeroallergen leads to barrier dysfunction, chronic esophageal inflammation, remodeling, and fibrosis. Patients with EoE have impaired quality of life because of dysphagia and other symptoms. They may also suffer social and psychological implications of food-related illness and expensive out-of-pocket costs associated with treatment. Disease burden in EoE is often compounded by the presence of comorbid type 2 inflammatory diseases. Current conventional treatments include elimination diet, proton pump inhibitors, and swallowed topical corticosteroids, as well as esophageal dilation in patients who have developed strictures. These treatments demonstrate variable response rates and may not always provide long-term disease control. There is an unmet need for long-term histologic, endoscopic, and symptomatic disease control; for targeted therapies that can normalize the immune response to triggers, reduce chronic inflammation, and limit or prevent remodeling and fibrosis; and for earlier diagnosis, defined treatment outcomes, and a greater understanding of patient perspectives on treatment. In addition, healthcare professionals need a better understanding of the patient perspective on disease burden, the disconnect between symptoms and disease activity, and the progressive nature of EoE and the need for continuous monitoring and maintenance treatment. In this review, we explore the progression of disease over the patient's lifespan, highlight the patient perspective on disease, and discuss the unmet need for effective long-term treatments.

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.

Endoscopic Ultrasonography in Children with Eosinophilic Esophagitis-A Review

Endoscopic ultrasonography (EUS) is a diagnostic endoscopy of the upper gastrointestinal tract, during which ultrasound of nearby organs is also performed. It is also possible to perform a fine needle aspiration biopsy. Currently, EUS is performed more frequently in adults. Despite some limitations, this diagnostic method is also more and more often performed in pediatric patients. Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus, which also occurs in children, and leads to irreversible fibrosis of the esophagus wall, if left untreated. Traditional methods of diagnosing and monitoring EoE treatment have significant limitations, and the use of EUS and total esophageal wall thickness (TWT) assessment may bring measurable benefits. Several studies have shown an increased thickening of TWT in EoE in children compared to pediatric patients with gastroesophageal reflux disease, and a decrease in TWT in adults who responded to EoE treatment. These results suggest that EUS and TWT measurement may become an important test in diagnostics, monitoring the effectiveness of therapy, assessing disease progression, and in individualizing the method and duration of EoE treatment also in children.

Proton pump inhibitor therapy reverses endoscopic features of fibrosis in eosinophilic esophagitis

BACKGROUND

Long-standing inflammation leads to esophageal remodeling with stricture formation in patients with eosinophilic esophagitis (EoE). The ability of proton pump inhibitors (PPI) to reverse endoscopic features of fibrosis is still unknown.

OBJECTIVE

To investigate the effect of a short course of PPI treatment in reducing endoscopic findings indicative of esophageal fibrosis in EoE patients.

METHODS

Cross-sectional analysis of the EoE CONNECT registry. Patients who received PPI to induce EoE remission were evaluated. Endoscopic features were graded using the EoE Endoscopic Reference Score (EREFS), with rings and strictures indicating fibrosis. Results were compared to those from patients treated with swallowed topic corticosteroids (STC).

RESULTS

Clinico-histological remission was achieved in 83/166 adult patients treated with PPI (50%) and in 65/79 (82%) treated with STC; among responders, 60 (36%) and 57 (72%) patients respectively achieved deep histological remission (<5 eosinophils/hpf). At baseline, mean±SD EREFS was lower in patients treated with PPI compared to those who received STC (p < 0.001). Short term treatment significantly reduced EREFS scores in patients treated either with PPI or STC as well as rings and strictures. Among patients treated with PPI, deep histological remission (<5 eosinophils/hpf) provided further reduction in total EREFS score.

CONCLUSION

Effective PPI therapy for EoE significantly reduced endoscopic esophageal fibrosis in the short term.

Factors Associated With Adequate Lamina Propria Sampling and Presence of Lamina Propria Fibrosis in Children with Eosinophilic Esophagitis

BACKGROUND & AIMS

Esophageal biopsies in children with eosinophilic esophagitis (EoE) are often inadequate for assessment of lamina propria and lamina propria fibrosis (LPF). For children with EoE, little is known about the factors associated with adequate lamina propria (aLP) sampling or the relationship among epithelial features in esophageal biopsies with and without LPF. We aimed to evaluate aLP in esophageal biopsies from children with and without EoE, identify factors associated with aLP and LPF, and examine the relationship among epithelial features in biopsies with and without LPF in children with EoE.

METHODS

In a retrospective study, we analyzed clinical, endoscopic, and histologic data from 217 children (124 with EoE and 94 without EoE [controls]) using descriptive statistics, logistic regression, Spearman's correlation, and receiver operating characteristic curve analysis. Active and inactive EoE were defined per the 2011 consensus guidelines.

RESULTS

aLP was observed in biopsies from higher proportion of children with EoE (69%) than controls (31%) (P = .0001). Active EoE was independently associated with aLP (adjusted odds ratio [aOR], 4.23; 95% CI, 1.00-18.13; P = .05). Patient sex (aOR for boys, 8.37; 95% CI, 1.23-56.74; P = .03) and peak eosinophil count (aOR, 1.02; 95% CI, 1.01-1.04; P = .01) were independently associated with LPF. Epithelial features were strongly interrelated in biopsies with LPF, and the presence of specific epithelial features was associated with LPF.

CONCLUSIONS

aLP was observed in a higher proportion of esophageal biopsies from children with EoE than controls. EoE status, patient sex, and peak eosinophil count were associated with aLP sampling and LPF. Given the intricate relationship between epithelial features and LPF, computational models can be developed to identify children with esophageal biopsies without aLP who are at risk for LPF.

Similarity and difference in the characteristics of eosinophilic esophagitis between Western countries and Japan

Over the past two decades, the incidence and prevalence of eosinophilic esophagitis (EoE) have risen rapidly, especially in Western countries, with cases in Japan also showing a gradual increase in recent years. However, similarities and differences regarding the characteristics of EoE between Western countries and Japan remain to be clearly elucidated. The current clinical guidelines for diagnosis include symptoms related to esophageal dysfunction and dense eosinophilic infiltration in the esophageal epithelium. Most affected patients in Japan are diagnosed incidentally during a medical health check-up and asymptomatic cases with typical endoscopic findings suggestive of EoE are frequently encountered. Clinical characteristics of EoE in Japanese are similar to those seen in Western populations. The predominant symptom is dysphagia, with food impaction extremely rare in Japanese cases. Linear furrows are the most frequently reported characteristic endoscopic finding, while an esophageal stricture or narrow caliber is rarely observed. Treatment strategies for EoE include drugs, dietary restrictions, and endoscopic dilation when the disease is advanced with stricture formation. Although single therapy using a proton-pump inhibitor has been shown to achieve symptomatic and histological response in the majority of patients in Japan, no prospective randomized control studies that evaluated drug or elimination diet therapy have been presented. Overall, EoE has similar clinical characteristics between Japanese and Western populations, while disease severity seems to be milder in Japan. Additional studies are necessary to determine genetic factors, natural history of the disease, and treatment efficacy of drugs and elimination diet as compared to Western populations.

Eosinophilic esophagitis and asymptomatic esophageal eosinophilia display similar immunohistological profiles

Patients with asymptomatic esophageal eosinophilia (aEE) do not exhibit clinical symptoms because of esophageal dysfunction, although they have endoscopic and histological findings similar to those of eosinophilic esophagitis (EoE). The cause of the symptoms and the differences between aEE and EoE are unclear. The aim of this study is to determine whether aEE and EoE are same disease entities by comparing immune-related tissue biomarkers using immunohistological staining. Esophageal biopsy specimens from 61 patients, including 18 with aEE and 43 with EoE, were analyzed. Immunofluorescence staining was performed to quantify the immune-related tissue biomarkers such as major basic protein, eosinophil-derived neurotoxin, eotaxin-3, and immunoglobulin G4. Data are presented as median (interquartile range). There were no significant differences in clinical, endoscopic, or histological features, between patients with aEE and EoE, with the exception of body mass index. There were no significant differences in all immune-related tissue biomarkers between both groups. In conclusions, EoE and aEE displayed similar immunohistological profiles. Hence, they may be similar disease entities with some common pathogenic mechanisms. Our findings suggest that patients with aEE also have histopathological esophageal inflammation.

Implementation of a biopsy protocol to improve detection of esophageal eosinophilia: a Danish registry-based study

BACKGROUND : In the North Denmark Region (580 272 inhabitants), only 0-4 cases of possible eosinophilic esophagitis (EoE) were identified annually in 1999-2010, suggesting underdiagnosis. This study aimed to increase the diagnosis of EoE by introducing a regional biopsy protocol for patients with dysphagia. METHODS : In 2011, leaders of regional endoscopy units attended a consensus meeting where a biopsy protocol was proposed. The national pathology registry was used to identify patients with esophageal eosinophilic inflammation during 2007-2017. RESULTS : Discussion resulted in consensus on a protocol to take eight biopsy samples in dysphagia patients (four biopsies from 4 cm and 14 cm above the esophagogastric junction-"4-14-4 rule") regardless of the macroscopic appearance, and to code eosinophilia systematically in the pathology registry. A pictogram showing the 4-14-4 rule was sent to all endoscopy units. The number of patients with esophageal eosinophilia detected per year increased 50-fold after the protocol was implemented in 2011 (median of 1 [interquartile range 0-3] vs. 52 [47-56]; P < 0.001), and the number of biopsy samples per patient doubled (median 4 [4-5] vs. 8 [6-9]; P < 0.04). Of 309 patients diagnosed with esophageal eosinophilia in 2007-2017, 24 % had erosive esophagitis or Barrett's esophagus, and 74 % had EoE. CONCLUSIONS : A consensus-based biopsy protocol and improved coding of eosinophilia in the pathology registry resulted in a 50-fold increase in patients diagnosed with esophageal eosinophilia/year. These patients can now receive treatment. The effort to establish the protocol and change the culture of endoscopists and pathologists was minimal.

Eosinophils in Eosinophilic Esophagitis: The Road to Fibrostenosis is Paved With Good Intentions

Eosinophilic esophagitis (EoE) is an antigen-driven disease associated with epithelial barrier dysfunction and chronic type 2 inflammation. Eosinophils are the defining feature of EoE histopathology but relatively little is known about their role in disease onset and progression. Classically defined as destructive, end-stage effector cells, eosinophils (a resident leukocyte in most of the GI tract) are increasingly understood to play roles in local immunity, tissue homeostasis, remodeling, and repair. Indeed, asymptomatic esophageal eosinophilia is observed in IgE-mediated food allergy. Interestingly, EoE is a potential complication of oral immunotherapy (OIT) for food allergy. However, we recently found that patients with peanut allergy may have asymptomatic esophageal eosinophilia at baseline and that peanut OIT induces transient esophageal eosinophilia in most subjects. This is seemingly at odds with multiple studies which have shown that EoE disease severity correlates with tissue eosinophilia. Herein, we review the potential role of eosinophils in EoE at different stages of disease pathogenesis. Based on current literature we suggest the following: (1) eosinophils are recruited to the esophagus as a homeostatic response to epithelial barrier disruption; (2) eosinophils mediate barrier-protective activities including local antibody production, mucus production and epithelial turnover; and (3) when type 2 inflammation persists, eosinophils promote fibrosis.

Eosinophilic esophagitis and asymptomatic esophageal eosinophilia display similar immunohistological profiles

Patients with asymptomatic esophageal eosinophilia (aEE) do not exhibit clinical symptoms because of esophageal dysfunction, although they have endoscopic and histological findings similar to those of eosinophilic esophagitis (EoE). The cause of the symptoms and the differences between aEE and EoE are unclear. The aim of this study is to determine whether aEE and EoE are same disease entities by comparing immune-related tissue biomarkers using immunohistological staining. Esophageal biopsy specimens from 61 patients, including 18 with aEE and 43 with EoE, were analyzed. Immunofluorescence staining was performed to quantify the immune-related tissue biomarkers such as major basic protein, eosinophil-derived neurotoxin, eotaxin-3, and immunoglobulin G4. Data are presented as median (interquartile range). There were no significant differences in clinical, endoscopic, or histological features, between patients with aEE and EoE, with the exception of body mass index. There were no significant differences in all immune-related tissue biomarkers between both groups. In conclusions, EoE and aEE displayed similar immunohistological profiles. Hence, they may be similar disease entities with some common pathogenic mechanisms. Our findings suggest that patients with aEE also have histopathological esophageal inflammation.

Symptom-based diagnostic approach for eosinophilic esophagitis

The prevalence of eosinophilic esophagitis (EoE) has been increasing in Japan. Although the diagnosis of EoE is based on simple criteria that include the presence of esophageal symptoms and esophageal eosinophilia on biopsies, there are several important issues associated with the diagnostic approach. Following an extensive literature search, the symptoms of 886 EoE cases in Japanese adults were analyzed and divided into three categories as follows: (1) typical symptoms, such as dysphagia (53%); (2) other upper GI symptoms (40%); and (3) no symptoms found during screening or medical examination, i.e., "asymptomatic esophageal eosinophilia" (19%). The diagnostic approach was reviewed according to these categories as well as according to the presence or absence of esophageal eosinophilia. The present manuscript describes the current therapeutic strategy of EoE and ultimately proposes a symptom-based diagnostic approach for EoE.

Eosinophilic esophagitis with a severe stenosis: report of a Japanese case

A 49 years old male, who had had postprandial dysphagia during the preceding 10 years, was referred to our hospital. Esophagogastroduodenoscopy (EGD) revealed longitudinal furrows and concentric rings in the mid to lower esophagus and stenosis in the lower esophagus. Histologic findings from esophageal biopsies showed eosinophilic infiltration (> 15 per high-power field). Under a diagnosis of eosinophilic esophagitis, an endoscopic bougie was performed, which resulted in symptomatic relief. Follow-up EGD revealed that the stenosis had improved, but histologic findings of eosinophilic esophagitis were remaining. Our case suggests that although rare, esophageal stenosis occurs in Japanese patients with EoE, and that the complication may be a consequence of prolonged disease. Other risks and the appropriate treatment for the prevention of stenosis need to be elucidated further.

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.