Suitable biopsy site for detection of esophageal eosinophilia in eosinophilic esophagitis suspected cases

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.

A Case of Early Barrett's Adenocarcinoma With Eosinophilic Esophagitis

A 61-year-old man presented with epigastric pain and underwent upper gastrointestinal endoscopy. A strongly erythematous area was found in the short segment of the Barrett's esophagus, and a biopsy revealed well-differentiated adenocarcinoma. Linear furrows were observed in the lower esophagus, and a biopsy of the lesion revealed eosinophil infiltration of 30 eosinophils per high-power field. Therefore, a diagnosis of Barrett's adenocarcinoma with eosinophilic esophagitis was made. Although rare, the incidence of Barrett's adenocarcinoma and eosinophilic esophagitis has been increasing in Japan in recent years, and the number of cases may increase in the future.

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.

Novel endoscopic approaches using the endocytoscopy for the target biopsy in esophageal eosinophilia

BACKGROUND AND AIMS

Multiple biopsies are recommended for the diagnosis of eosinophilic esophagitis (EoE) because inflammatory changes are frequently patchy. Reports on EoE using endocytoscopy (ECS) are limited. This present study aimed to assess if diagnostic yield improves by adding ECS on conventional white light imaging (WLI) in patients with esophageal eosinophilia (EE).

METHODS

A total of 284 biopsy specimens from 71 patients with a known diagnosis of EE were enrolled and divided into the WLI group (156 specimens) or the ECS group (128 specimens). Four biopsies from 5 and 10 cm proximal to the esophagogastric junction were taken from each patient. In the ECS group, the biopsy was performed where bilobed nuclei were observed. The biopsy sensitivity for EE, eosinophil count of a single specimen and the biopsy sensitivity of each endoscopic finding were evaluated between both groups.

RESULTS

The sensitivity of a single biopsy specimen was higher in the ECS group than that of the WLI group (62.5 vs. 41.7%, P < 0.001). In addition, the median eosinophil count in the ECS group was significantly higher [19 vs. 6.5/high-power field (HPF), P < 0.001]. For each endoscopic finding, ECS-based biopsy had higher sensitivity than that of WLI in the diagnosis of edema (33.1 vs. 11.3%, P = 0.007) and linear furrows (75.8 vs. 52%, P = 0.005).

CONCLUSION

This study showed that adding ECS to WLI improved the biopsy sensitivity and eosinophil detection in patients with EE.

Usefulness of Endoscopy for the Detection and Diagnosis of Primary Esophageal Motility Disorders and Diseases Relating to Abnormal Esophageal Motility

Esophagogastroduodenoscopy (EGD) is performed to rule out organic diseases in the diagnosis of esophageal motility disorders (EMDs). Abnormal endoscopic findings can be observed during EGD, which indicate the presence of EMDs. Several endoscopic findings at both the esophagogastric junction and esophageal body that are related to EMDs have been reported. Gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EoE) could be detected during EGD, and these diseases are often associated with abnormal esophageal motility. Image-enhanced endoscopy (IEE) could improve the detection of these diseases during EGD. Although no report has been published previously on the potential usefulness of IEE in the endoscopic diagnosis of EMDs, IEE can be used to detect disorders that can be associated with abnormal esophageal motility.

Eosinophilic Gastrointestinal Diseases: The Pathogenesis, Diagnosis, and Treatment

Eosinophilic gastrointestinal diseases are delayed-type chronic allergic disorders that show gastrointestinal eosinophil dense infiltration, with an exaggerated Th2-type immune reaction considered to be an important mechanism. These diseases can be roughly divided into two types: eosinophilic esophagitis, mainly found in young and middle-aged men, and eosinophilic gastroenteritis, which is found in both genders equally. A diagnosis of eosinophilic esophagitis is suspected when characteristic endoscopic findings, including longitudinal furrows and rings, are noted. However, characteristic endoscopic abnormalities are rarely found in cases with eosinophilic gastroenteritis, so multiple biopsy sampling from the apparently normal gastrointestinal mucosal surface is important for making an accurate diagnosis. The administration of systemic glucocorticoid is the standard treatment for eosinophilic gastroenteritis, while acid inhibitors and topical glucocorticoid swallowing therapy are effective for eosinophilic esophagitis. Anti-cytokine therapies for eosinophilic gastrointestinal diseases are currently under development.

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.

Beige mucosa observable under narrow-band imaging indicates the active sites of eosinophilic esophagitis

BACKGROUND AND AIM

The majority of patients with eosinophilic esophagitis (EoE) are likely to have observable features under narrow-band imaging, namely beige mucosa. However, the histological features and clinical implications of beige mucosa have not been investigated. The aim of this study was to determine whether beige mucosa could serve as an endoscopic marker for predicting active inflammatory sites of EoE.

METHODS

We retrospectively analyzed both the narrow-band images and biopsied specimens of 77 esophageal lesions from 35 consecutive patients with EoE. We divided these specimens into two groups: target biopsied specimens from beige mucosa (beige group) and specimens biopsied from non-beige mucosa (non-beige group). The number of eosinophils per high-powered field, thickness of the superficial differentiated cell layer, and depth of the hemoglobin component from the surface layer were compared between the two groups.

RESULTS

Forty-four out of the 45 specimens were diagnosed as histological active lesions in the beige group. The sensitivity, specificity, and overall accuracy of beige mucosa in predicting EoE activity were 97.8%, 96.9%, and 97.8%, respectively. Compared with the non-beige group, specimens in the beige group had a significantly thinner superficial differentiated cell layer.

CONCLUSIONS

Beige mucosa is associated with thinning of the normal superficial differentiated cell layer, and these histological changes in the active inflammatory sites of EoE could be recognized endoscopically as color differences. Beige mucosa may serve as an endoscopic indicator for predicting the histological activity of EoE.

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.

Host-Microbiota Interactions in the Esophagus During Homeostasis and Allergic Inflammation

BACKGROUND & AIMS

Microbiota composition and mechanisms of host-microbiota interactions in the esophagus are unclear. We aimed to uncover fundamental information about the esophageal microbiome and its potential significance to eosinophilic esophagitis (EoE).

METHODS

Microbiota composition, transplantation potential, and antibiotic responsiveness in the esophagus were established via 16S ribosomal RNA sequencing. Functional outcomes of microbiota colonization were assessed by RNA sequencing analysis of mouse esophageal epithelium and compared with the human EoE transcriptome. The impact of dysbiosis was assessed using a preclinical model of EoE.

RESULTS

We found that the murine esophagus is colonized with diverse microbial communities within the first month of life. The esophageal microbiota is distinct, dominated by Lactobacillales, and demonstrates spatial heterogeneity as the proximal and distal esophagus are enriched in Bifidobacteriales and Lactobacillales, respectively. Fecal matter transplantation restores the esophageal microbiota, demonstrating that the local environment drives diversity. Microbiota colonization modifies esophageal tissue morphology and gene expression that is enriched in pathways associated with epithelial barrier function and overlapping with genes involved in EoE, including POSTN, KLK5, and HIF1A. Finally, neonatal antibiotic treatment reduces the abundance of Lactobacillales and exaggerates type 2 inflammation in the esophagus. Clinical data substantiated loss of esophageal Lactobacillales in EoE compared with controls.

CONCLUSIONS

The esophagus has a unique microbiome with notable differences between its proximal and distal regions. Fecal matter transplantation restores the esophageal microbiome. Antibiotic-induced dysbiosis exacerbates disease in a murine model of EoE. Collectively, these data establish the composition, transplantation potential, antibiotic responsiveness, and host-microbiota interaction in the esophagus and have implications for gastrointestinal health and disease.

Clinical Characteristics and Treatment Outcomes of Patients with Eosinophilic Esophagitis and Eosinophilic Gastroenteritis

BACKGROUND

Eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE), part of the spectrum of eosinophilic gastrointestinal disorders (EGID), share pathogenic similarities. We examined differences regarding clinical characteristics and treatment outcomes between EoE and EGE cases.

METHODS

Two-hundred fifteen EGID patients, including 181 with EoE and 34 with EGE, diagnosed at Shimane University Hospital between February 2011 and March 2019 were enrolled. Information regarding clinical parameters and treatment outcomes was reviewed.

RESULTS

EoE showed significant male predominance (82.3%) as compared with EGE (50.0%) (p < 0.001). Furthermore, patients with EoE were significantly older and had a higher body mass index (24.8 ± 4.0 vs. 22.2 ± 4.3, p < 0.05). Over 90% of the EoE patients were initially given proton pump inhibitor (PPI) treatment, of whom 73.2% showed clinical and histological remission. Vonoprazan, a more potent acid inhibitor than PPI, was effective in two-thirds of the nonresponsive EoE patients initially treated with a PPI. In contrast, oral glucocorticoid administration was mainly given to patients with EGE (58.8%). Of 13 EGE patients treated with a food-elimination diet, responsible foods were successfully identified in 9, with 7 controlled in a state of remission without glucocorticoid therapy.

CONCLUSIONS

We found different clinical characteristics and treatment strategies in the present EoE and EGE cases. Most of the EoE patients responded to and were maintained by acid suppressive therapy, using PPI or vonoprazan. For EGE patients, glucocorticoid administration was mainly used though food-elimination diet therapy also showed beneficial effects.

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.

Diagnostic Value of Mid-esophageal Biopsies in Pediatric Patients With Eosinophilic Esophagitis

INTRODUCTION

Eosinophilic esophagitis (EoE) is histologically defined as the presence of 15 or more intraepithelial eosinophils per high-power fields. Limited consensus exists on where to sample the esophagus in pediatrics. This study aimed to identify whether endoscopic and histologic examination of the mid esophagus offers diagnostic value compared to proximal/distal esophageal biopsies.

METHODS

A retrospective chart review of pediatric patients with EoE was performed. Endoscopic and histologic parameters were assessed at the initial and follow-up visits, and concordance between proximal/distal biopsy and mid biopsy was determined.

RESULTS

A total of 100 patients with a mean age of 9.6 ± 4.07 years were included. Endoscopic parameters between proximal/distal and mid esophagus were concordant in 84% to 97% of patients (initial assessment) and in 80% to 97% of patients (at follow-up). Mid esophagus showed endoscopic abnormalities, which were absent at the proximal/distal esophagus in 1% to 5% of patients, as well as histologic abnormalities in 2% to 8% of patients overall at initial and follow-up examinations.

CONCLUSIONS

We recommend continued endoscopic and histologic assessment of the proximal/distal biopsy; however, examination of the mid esophagus does offer small diagnostic value in our subset of patients. Future studies need to be conducted before conclusive recommendations supporting the use of mid-esophageal biopsies can be made.

Clinical Features of Esophageal Eosinophilia According to Endoscopic Phenotypes

Objective Esophageal eosinophilia (EE), a histological hallmark of eosinophilic esophagitis, is classified into two endoscopic phenotypes: localized and diffuse EE. Our aim was to determine the prevalence of EE localized in the lower esophagus and to describe its clinical features in comparison with diffuse EE. Methods Data from 81 consecutive patients with EE were retrospectively investigated. EE was histologically defined as ≥15 eosinophils per high-power field. Based on the endoscopic appearance with a histological assessment, EE was classified as either diffuse or localized type. We compared the clinical features, including the medical treatment and natural course, between the two types. Results Of the 81 patients, 52 (64.2%) had diffuse EE, and 29 (35.8%) had localized EE. Among men patients, localized EE was significantly more common than diffuse EE. In localized EE, dysphagia and food impaction were less prevalent, and the presence of rings was significantly less common than in diffuse EE. Acid-suppressive therapy was administered to only 3 of the 29 patients with localized EE. In asymptomatic patients, especially those with localized EE, endoscopic abnormalities did not worsen but rather improved in some findings, such as with regard to furrows or exudate, during the natural course of three years without medical treatment. Conclusion Localized EE has a strong predilection for men patients and accounted for more than one third of all cases of EE. This condition appears to be less symptomatic and necessitates milder medical treatment than diffuse EE and might not worsen progressively.

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.

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.

Clinical and endoscopic characteristics of eosinophilic esophagitis in Japan: a case-control study

Background

Eosinophilic esophagitis (EoE) is an allergy-associated clinicopathologic condition gaining an increasing amount of recognition in various areas of the world. While the clinical definition and characteristics may differ depending on country and region, sufficient studies have not yet been performed in Japan.

Objective

To assess the prevalence of EoE among the Japanese population and the clinical features associated with the disease.

Methods

Endoscopic data from January 2012 to October 2018 was gathered from 9 Japanese clinical institutes. EoE, defined as esophageal mucosal eosinophilia of at least 15 eosinophils per high-power field, was determined based on esophageal biopsies. Clinical and endoscopic patterns in the cases with EoE were investigated and compared with 186 age- and sex-matched controls.

Results

From 130,013 upper endoscopic examinations, 66 cases of EoE were identified (0.051%; mean age, 45.2 years [range, 7-79 years]; 45 males). Twenty-five patients (37.9%) with EoE were diagnosed by endoscopy during a medical check-up. Patients with EoE had more symptoms (69.7% vs. 10.8%, p < 0.01) such as dysphagia and food impaction, and more allergies (65.2% vs. 23.7%, p < 0.01) compared with the controls. The prevalence of atrophic gastritis was lower in EoE patients than in the controls (20.0% vs. 33.3%, p < 0.05).

Conclusion

The prevalence of EoE in the Japanese population was 0.051% which was comparable with previous reports in Japan. History of allergies and the absence of atrophic gastritis were associated with EoE.

Eosinophilic gastrointestinal diseases - Pathogenesis, diagnosis, and treatment

Eosinophilic gastrointestinal diseases (EGIDs) are divided into eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE), depending on the involved gastrointestinal tract, though both are considered to be chronic Th2-type allergic diseases caused by food or environmental allergens. In development of EoE, refluxed gastric acid may also have an important role. For diagnosis of EGIDs, the presence of symptoms possibly originating from the involved gastrointestinal tract and dense eosinophil infiltration are important factors. Imaging studies, including endoscopy and computed tomography, along with histopathological examinations of biopsy specimens are useful for diagnosis, whereas laboratory testing of blood, urine, and stool samples has limited value. Three useful options for treating EoE patients are acid inhibitors, swallowed topical corticosteroids, and an elimination diet, while systemic administration of glucocorticoids is the standard treatment of EGE, though information is limited. Since the prevalence of EGIDs is increasing in Western countries as well as Japan, development of effective treatments based on sufficient evidence is becoming an urgent need.

Eosinophilic esophagitis: early diagnosis is the key

Eosinophilic esophagitis (EoE) is a disorder which affects all ages, from infancy through adulthood. It typically affects atopic individuals (Table 1) and is a chronic allergic disorder, with foods ubiquitous in the diet being the most described trigger of this isolated eosinophilic inflammation of the esophagus in both adults and children. This inflammatory process leads to esophageal symptoms such as dysphagia and feeding intolerance. In this review, we provide a brief overview of the current state of EoE therapy and symptomatology and then try to make the case for early diagnosis and treatment to prevent some of the long-term consequences of esophageal inflammation.

Is Asymptomatic Esophageal Eosinophilia the Same Disease Entity as Eosinophilic Esophagitis?

Eosinophilic esophagitis (EoE) is an allergic inflammatory disorder that is characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation.^1,2 Its prevalence has been increasing rapidly in both Western and Asian countries. In Japan, most of the cases of esophageal eosinophilia (EE) are found in an upper endoscopy examination for gastric cancer screening performed during a comprehensive health check-up.^3,4 Indeed, we frequently encounter patients with asymptomatic EE showing typical endoscopic findings, such as linear furrows, as well as histologic findings compatible with EoE. However, the current clinical guidelines for EoE diagnosis include symptoms related to esophageal dysfunction, thus patients without symptoms do not fulfill the diagnostic criteria.^1,2 The clinical characteristics remain to be fully elucidated,⁵ thus we aimed to clarify clinical features of asymptomatic EE as compared with those of EoE.

[Recent progress in the research of Eosinophilic GastroIntestinal Diseases (EGIDs)]

Eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE), which are included in eosinophilic gastrointestinal disorders (EGIDs), are allergic gastrointestinal diseases mainly caused by food allergens, which features dense infiltration of eosinophiles in the gastrointestinal mucosa. A possible mechanism of these diseases are Th2 type allergic reactions, including IL-5, IL-13, and IL-15, thymic stromal protein (TSLP), and eotaxin 3, which are considered to have important roles. The number of patients with EoE is rapidly increasing in both Western and Asian countries. In Japan, a research group of the Ministry of Health, Labor and Welfare has announced recommendations for the diagnosis and management of EoE and EGE in 2015. For a diagnosis of EoE, endoscopic abnormalities and histological confirmation of dense eosinophile infiltration in the esophageal epithelial layer are important, in addition to identifying dysphagia symptoms. As for eosinophilic gastroenteritis, blood test findings are more useful and the role of an endoscopic examination is reduced. Glucocorticoid administration is standard treatment for these diseases, while proton pump inhibitors are frequently effective for EoE. As for EoE, on the one hand, a variety of studies have been performed and new findings collected. On the other hand, information concerning EGE is limited and additional evidence is needed to establish effective treatment options.

Eosinophilic esophagitis in Japan: Focus on response to acid suppressive therapy

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition characterized by esophageal dysfunction and dense eosinophilic infiltration of esophageal epithelium. According to clinical consensus and guidelines published in 2011, esophageal eosinophilia was classified into two entities based on response to proton pump inhibitor (PPI) administration: EoE and PPI-responsive esophageal eosinophilia (PPI-REE). We have performed a series of investigations to determine whether EoE is actually different from PPI-REE. Consistent with Western reports, more than half of our examined patients with symptomatic esophageal eosinophilia suggestive of EoE achieved histological remission with single PPI therapy. Furthermore, our comparisons of clinical, endoscopic, and histopathological findings between patients with EoE and those with PPI-REE revealed nearly no differences between them. We also compared gene expression profiles in mucosal biopsy specimens between those groups and found that microarray findings obtained from PPI-REE patients substantially overlapped with those from EoE patients, suggesting that both represent the same condition or are variations of a single disease. In addition, we have noted that more than half of EoE patients who show resistance to a PPI therapy respond to vonoprazan, a novel potassium-competitive acid blocker that has been shown to provide more potent and sustained suppression of gastric acid secretion than PPIs. Our results indicate that PPI-REE may constitute a subtype of EoE. Based on novel evidence including results obtained in our studies, the most recently updated guidelines have included responders to PPI therapy within the spectrum of EoE, abandoning the term PPI-REE.

Similarities and differences among eosinophilic esophagitis, proton-pump inhibitor-responsive esophageal eosinophilia, and reflux esophagitis: comparisons of clinical, endoscopic, and histopathological findings in Japanese patients

BACKGROUND

Esophageal eosinophilia is classified as either eosinophilic esophagitis (EoE) or proton-pump inhibitor-responsive esophageal eosinophilia (PPI-REE), depending on the response to PPI treatment. The aim of this study was to compare the clinical, endoscopic, and histopathological findings of EoE and PPI-REE in Japanese patients. In addition, the characteristics of these cases were compared with those of reflux esophagitis (RE) cases.

METHODS

Eleven patients diagnosed with EoE, 16 with PPI-REE, and 39 with RE, who were all consecutively examined from 2005 to 2015 at Shimane University Hospital, were enrolled. Clinical, endoscopic, and histopathological esophageal findings in these groups were retrospectively examined and compared.

RESULTS

The differences in the clinical characteristics of EoE and PPI-REE were not remarkable, though patients with EoE and PPI-REE were younger, presented a higher prevalence of allergic comorbidities, and complained of symptoms of dysphagia more frequently than those with RE. The only noteworthy differences between EoE and PPI-REE were more frequent reports of asthma (36.4 vs. 2.6 %) and food allergy (27.3 vs. 0 %) by patients with EoE (P < 0.05, P < 0.05, respectively). Endoscopic findings in patients with EoE and PPI-REE were similar, with the presence of esophageal erosions in a small percentage of PPI-REE cases being the only difference. There were no histopathological differences between EoE and PPI-REE.

CONCLUSIONS

Comparisons of clinical, endoscopic, and histopathological findings between EoE and PPI-REE showed that these two types have similar characteristics, though EoE patients showed a higher atopic background. Predicting PPI responsiveness in cases with esophageal eosinophilia is difficult and requires further investigation.

Specific locations of linear furrows in patients with esophageal eosinophilia

BACKGROUND AND AIM

Linear furrows are the most frequently found endoscopic abnormality in patients with esophageal eosinophilia (EE); however, the precise endoscopic features remain to be fully elucidated. Here, we aimed to clarify the endoscopic features of EE, essential for the diagnosis of eosinophilic esophagitis (EoE), by focusing on the specific locations of linear furrows in a Japanese population.

METHODS

We enrolled 70 cases with EE (≥15 eosinophils/high-power field) who were diagnosed at our hospital and related facilities. Information regarding endoscopic findings and clinical parameters was retrospectively reviewed. Next, the position of linear furrows in relation to esophageal longitudinal folds (ridge or valley) was evaluated in each case and compared with the position of mucosal breaks in patients with reflux esophagitis. Finally, the relationship between linear furrows and eosinophilic infiltration was evaluated.

RESULTS

Of the 70 EE patients, 63 (90%) had linear furrows. Those occurred in a radial pattern and were widespread throughout the lower to upper esophagus, and exclusively found in esophageal longitudinal mucosal fold valleys, not on ridges, which was different from the position of mucosal breaks in patients with reflux esophagitis. Increased eosinophilic infiltration was significantly more frequent in linear furrows in the valleys (93%) as compared to mucosa on adjacent ridges (60%) (P < 0.05).

CONCLUSION

Investigation of these endoscopic characteristics, especially by focusing on linear furrows in esophageal mucosal fold valleys, may provide important clues for more accurate diagnosis of EoE.