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

Efficacy and Safety of Monoclonal Antibodies for the Treatment of Eosinophilic Esophagitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIMS

Monoclonal antibodies (MAbs) have clinical benefits for treating several atopic diseases. However, consensus on its use for eosinophilic esophagitis (EoE) is lacking. The present meta-analysis aimed to compare the efficacy and safety of MAbs versus placebo for treating EoE.

METHODS

We searched PubMed, Embase, and Cochrane Library for randomized controlled trials (RCTs). The primary outcomes were changes in peak esophageal eosinophils count/high power field (HPF) and mean esophageal eosinophils count/HPF. The secondary outcomes were changes in the EoE-Histology Scoring System (EoE-HSS), Endoscopic Reference Score (EREFS), dysphagia score, and adverse events (AEs). We compared binary outcomes using risk ratio (RR) and continuous outcomes using mean difference (MD) or standardized mean difference (SMD), with 95% confidence interval (CI). Considering the diversity of mechanistic properties of MAbs, a pre-specified subgroup analysis by MAb mechanism of action was performed for all outcomes, provided that at least two studies were in each subgroup. Heterogeneity was assessed using Cochran's Q test and I2 statistics.

RESULTS

6 RCTs were included (533 patients). Compared to placebo, MAbs led to a significant reduction in peak esophageal eosinophils count/HPF (MD -0.78; CI 95% -0.87, -0.6801) and mean esophageal eosinophils count/HPF (SMD -0.79; CI 95% -1.5, -0.08). Moreover, MAbs significantly reduced EoE-HSS scores (grade score: SMD -9.31; 95% CI -13.95, -4.6701; stage score: SMD -10.18; 95% CI -15.06, -5.31), EREFS (SMD -5.95; CI 95% -9.19, -2.71) and dysphagia score (SMD -1.79; CI 95% -3.36, -0.23) without increasing AEs compared to placebo. Among those MAbs whose mechanism of action includes the blockage of the receptor for IL-13 (Dupilumab, QAX576, and RPC4046), the scores of EoE-HSS grade, EoE-HSS stage, EREFS, and dysphagia were significantly reduced, and they presented a similar risk of overall and serious AEs compared to placebo.

CONCLUSION

MAbs seem effective and safe in reducing esophageal eosinophil infiltrate, EoE-HSS score, EREFS score, and dysphagia symptoms in patients with EoE. However, further evidence is needed to establish its place in EoE management.

Long-term course of untreated asymptomatic esophageal eosinophilia and minimally symptomatic eosinophilic esophagitis

Background and study aims The long-term course of untreated asymptomatic esophageal eosinophilia (aEE) and minimally symptomatic eosinophilic esophagitis (mEoE) are not well understood. This study aimed to clarify this course. Patients and methods A total of 36 patients with EE who were endoscopically followed up for more than 5 years, and who underwent more than one endoscopy evaluation after the first diagnosis, were investigated. These patients were divided into two groups according to the presence or absence of the continuous treatment: no treatment group (NT group, n=22) and proton pump inhibitor/potassium competitive acid blocker group (Tx group, n=14). Symptoms and endoscopic and histological findings were retrospectively reviewed according to endoscopic phenotypes. Endoscopic assessment was performed using the EoE endoscopic reference score (EREFS). Results The median follow-up period was 84.5 months in the Tx group and 92 months in the NT group. During the follow-up period, about half of the patients in the Tx-diffuse group persisted EREFS >3, while the remaining half had EREFS ≤2. The total EREFS in the NT-diffuse group remained almost unchanged (median: 2-4) without apparent exacerbation. In contrast, EREFS in the NT-localized group exhibited an unchanged or gradually decreasing trend, with statistical significance from the first diagnosis to 72 to 83 months after. Conclusions Untreated aEE and mEoE are not likely to worsen even without treatment at least for a median follow-up of 7 years. Instead, the localized type may spontaneously improve, implying a different pathogenesis in the presence of the diffuse type. Further studies should clarify the long-term prognosis.

Esophageal organoids: applications and future prospects

Organoids have been developed in the last decade as a new research tool to simulate organ cell biology and disease. Compared to traditional 2D cell lines and animal models, experimental data based on esophageal organoids are more reliable. In recent years, esophageal organoids derived from multiple cell sources have been established, and relatively mature culture protocols have been developed. Esophageal inflammation and cancer are two directions of esophageal organoid modeling, and organoid models of esophageal adenocarcinoma, esophageal squamous cell carcinoma, and eosinophilic esophagitis have been established. The properties of esophageal organoids, which mimic the real esophagus, contribute to research in drug screening and regenerative medicine. The combination of organoids with other technologies, such as organ chips and xenografts, can complement the deficiencies of organoids and create entirely new research models that are more advantageous for cancer research. In this review, we will summarize the development of tumor and non-tumor esophageal organoids, the current application of esophageal organoids in disease modeling, regenerative medicine, and drug screening. We will also discuss the future prospects of esophageal organoids.

Linked color imaging improves the diagnostic accuracy of eosinophilic esophagitis

Objectives

To assess the usefulness of linked color imaging (LCI), a recently developed image‐enhanced endoscopy technique, in the endoscopic diagnosis of eosinophilic esophagitis (EoE).

Methods

Thirty white light images (WLIs) and 30 WLI+LCI images collected from patients with and without EoE were randomly and blindly reviewed by 10 endoscopists, including four experts (Exs) and six non‐Exs. Edema, ring, exudate furrows, and strictures were rated on the adjusted EoE endoscopic reference score; the diagnosis of EoE was assessed. Using the kappa value, inter‐ and intra‐observer agreements were analyzed among endoscopists.

Results

WLI+LCI images had a higher diagnostic accuracy for EoE than WLIs (0.85 vs. 0.70, respectively), especially in non‐Exs or endoscopists with no experience with EoE patients. Inter‐observer agreement for WLI+LCI images statistically surpassed WLIs for furrows (kappa, 0.73 vs. 0.67, respectively; p = 0.0013), stricture (kappa, 0.51 vs. 0.39, respectively; p = 0.0072), and diagnosis (kappa, 0.67 vs. 0.57, respectively; p < 0.0001) of EoE. The increase in inter‐observer agreement in WLI+LCI images allowed for a reduction in the differences between the Exs and non‐Ex endoscopists. Intra‐observer agreement for WLI+LCI images surpassed WLIs for a ring (kappa, 0.62 vs. 0.43, p = 0.0052), and a similar trend was found in exudates, furrows, and diagnosis irrespective of the Exs or non‐Exs.

Conclusions

LCI can contribute to the improvement of the endoscopic diagnosis for EoE, with “moderate” to “substantial” consistency, by enhancing the visibility of abnormal findings, leading to reduced diagnostic disparities among endoscopists.

Eosinophilic Esophagitis—What Do We Know So Far?

Eosinophilic esophagitis is a Th-2 antigen-mediated disease in which there is an influx of eosinophils to all layers of the esophagus, triggering an inflammatory response. Chronic inflammatory process causes esophageal remodeling, leading to difficulties in swallowing. Food impaction, heartburn, and chest pain are other characteristic (but not pathognomonic) symptoms in adults. Although the disease has only been described since in the early 1970s, its incidence and prevalence are rapidly growing, especially in Western countries. According to the diagnostic guidelines, there should be at least 15 eosinophils visible per high-power field in biopsies obtained from different sites in the esophagus upon endoscopy with relevant esophageal symptoms. Other diseases that can cause esophageal eosinophilia should be ruled out. Eosinophilic esophagitis treatment may be challenging; however, new methods of management have recently emerged. The currently used proton pump inhibitors, topical corticosteroids, and elimination diet are combined with biological treatment. New methods for disease diagnostics and clinical course assessment are also available. This review presents current knowledge about the disease, supported by the latest research data.

Application of Convolutional Neural Networks for Diagnosis of Eosinophilic Esophagitis Based on Endoscopic Imaging

Subjective symptoms associated with eosinophilic esophagitis (EoE), such as dysphagia, are not specific, thus the endoscopic identification of suggestive EoE findings is quite important for facilitating endoscopic biopsy sampling. However, poor inter-observer agreement among endoscopists regarding diagnosis has become a complicated issue, especially with inexperienced practitioners. Therefore, we constructed a computer-assisted diagnosis (CAD) system using a convolutional neural network (CNN) and evaluated its performance as a diagnostic utility. A CNN-based CAD system was developed based on ResNet50 architecture. The CNN was trained using a total of 1192 characteristic endoscopic images of 108 patients histologically proven to be in an active phase of EoE (≥15 eosinophils per high power field) as well as 1192 normal esophagus images. To evaluate diagnostic accuracy, an independent test set of 756 endoscopic images from 35 patients with EoE and 96 subjects with a normal esophagus was examined with the constructed CNN. The CNN correctly diagnosed EoE in 94.7% using a diagnosis per image analysis, with an overall sensitivity of 90.8% and specificity of 96.6%. For each case, the CNN correctly diagnosed 37 of 39 EoE cases with overall sensitivity and specificity of 94.9% and 99.0%, respectively. These findings indicate the usefulness of CNN for diagnosing EoE, especially for aiding inexperienced endoscopists during medical check-up screening.

The role of advanced endoscopy in the management of inflammatory digestive diseases (upper gastrointestinal tract)

The Japan Gastroenterological Endoscopy Society held four serial symposia between 2019 and 2020 on the state-of-the-art of issues related to upper GI inflammatory diseases. This review discusses some of the topics addressed in these symposia. The papers regarding nonerosive reflux disease, recent improvements in intraesophageal pH-impedance monitoring and endoscopic diagnosis using image-enhanced endoscopy have been published. Many publications have addressed its usefulness in endoscopic treatment of gastroesophageal reflux disease such as anti-reflux mucosectomy. In the management of eosinophilic esophagitis, since the symptoms are subjective, objective indicators have been sought, and ultrasonography and high-resolution manometry may be useful tools for evaluation. The natural course of this condition, especially of asymptomatic cases, is not well clarified. Some newly developed anti-acid or anti-inflammatory medicines are now under investigation. With regard to autoimmune gastritis, because of widespread medical examinations, diagnosis of asymptomatic cases has been increasing. Recently, its endoscopic characteristics have become clear and the natural history of these conditions is being elucidated. The Kyoto Classification of Gastritis has been reported to be useful not only for Helicobacter pylori diagnosis but also for identification of risks of gastric cancer. Its usefulness is now recognized in Asia and Europe.

Utility of Direct Fast Scarlet Staining in the Histopathological Diagnosis of Eosinophilic Esophagitis: A Short Report

Eosinophilic esophagitis (EoE), an atopic disease of the esophagus, has become increasingly recognized over the last 15 years. The epidemiology of EoE has now been reported from many countries around the world. While the clinical diagnosis of this disease depends on the patient’s clinical manifestations, the final diagnosis should be made based on the histopathological examination of esophageal mucosal biopsies. In the diagnosis of EoE, to facilitate the appropriate treatment of patients, it is extremely important to precisely recognize the presence of eosinophils in biopsy specimens of the esophageal mucosa. If eosinophils are present, EoE patients should be referred to an allergist for appropriate management with dietary modification, pharmacological agents (including corticosteroids), and/or mechanical dilation of the esophagus. We herein present and recommend the use of direct fast scarlet staining for the easy and precise recognition of eosinophils in biopsy specimens of the esophageal mucosa, a technique that has been routinely used in our laboratory.