Clinical features of eosinophilic esophagitis: ten Japanese cases

Proton Pump Inhibitor Therapy for Eosinophilic Esophagitis: History, Mechanisms, Efficacy, and Future Directions

Over the past decade, the role of proton pump inhibitor (PPI) medication has evolved from a diagnostic tool for Eosinophilic Esophagitis (EoE), by excluding patients with PPI responsive esophageal eosinophilia (PPI-REE), to a therapy for EoE. This transition resulted from the Updated International Consensus Diagnostic Criteria for Eosinophilic Esophagitis: Proceedings of the Appraisal of Guidelines for Research and Evaluation II (AGREE) Conference to support PPI therapy for EoE in children and adults. Additional recent advances have suggested a role for genetic variations that might impact response to PPI therapy for EoE. This review article will explore a brief background of EoE, the evolution of PPI therapy for EoE and its proposed mechanisms, efficacy and safety in children and adults, and considerations for future PPI precision medicine in patients with EoE.

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.

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.

Predicting pediatric esophageal wall thickness: An EUS study

Background and Objective

EUS has been shown in two small series to be capable of documenting increases in the total esophageal wall thickness (TWT) in children and adults with eosinophilic esophagitis (EoE). To apply EUS-derived TWT in clinical situations or in scientific investigations in pediatric EoE, measurements of esophageal TWT in children of differing ages and heights are required.

Materials and Methods

Thirty patients (18M: 12F, 7 months to 20 years and 10 months) with a history of esophageal symptoms, but no endoscopic or histologic criteria of EoE were studied using a through the scope 20 MHZ Olympus Ultrasound miniprobe UM-3R (Olympus America, Center Valley Pa 18034) through a GIF Q180 or 160 (Olympus) standard pediatric upper endoscope. The mucosa, the mucosa plus submucosa, and the TWT were measured in the mid- and distal esophagus immediately before taking diagnostic biopsies.

Results

Measurements from both sites showed a statistically significant increase in TWT as a function of age (P < 0.001) and height (P < 0.001), as did the individual layers. The width of the mucosa and the submucosa were equivalent and together, they contributed more than half of the entire TWT. There were no significant differences between the means of the mid- and distal esophageal measurements. A multiple regression equation that can predict TWT based on age, with 95% confidence limits, is presented.

Conclusions

EUS has demonstrated that esophageal TWT in a cohort of control children correlates with height and with age and has provided insights into the organization of the esophageal wall. Esophageal TWT values obtained by EUS can now be interpreted to recognize esophageal wall thickening throughout childhood.

The Predictive Factors of Responsiveness to Proton Pump Inhibitor Therapy for Eosinophilic Esophagitis

Approximately half of patients with eosinophilic esophagitis (EoE) respond clinically and histologically to proton pump inhibitor (PPI) therapy. Although recent guidelines suggest that PPI-responders and non-responders were included in EoE, it is important to investigate the predictive factors of PPI- responsiveness. This study aimed to determine the rate of PPI- responders and compare the characteristics of PPI-responders and non-responders. Fifty-nine patients with esophageal eosinophilia received PPI therapy for eight weeks, and its efficacy was assessed. PPI- responsiveness was diagnosed based on the relief in symptoms and reduction of intraepithelial eosinophilic infiltration to <15 per high-power field (hpf) after PPI therapy. Multivariate analysis was performed to identify factors associated with PPI-responders. Of the 59 patients, 41 (69.5%) were diagnosed with PPI-responders. The rate of gastrointestinal (GI) screening in the indications for endoscopy was significantly higher in patients with PPI- responders than in those with non-responders. On multivariate analysis, GI screening and presence of reflux esophagitis was associated with an increased odds ratio (OR) of PPI-responders, but presence of rings with a decreased OR of PPI-responders. Presence of reflux esophagitis and absence of rings on endoscopy especially during GI screening might be significant predictive factors for PPI response in patients with EoE.

Updated International Consensus Diagnostic Criteria for Eosinophilic Esophagitis: Proceedings of the AGREE Conference

BACKGROUND & AIMS

Over the last decade, clinical experiences and research studies raised concerns regarding use of proton pump inhibitors (PPIs) as part of the diagnostic strategy for eosinophilic esophagitis (EoE). We aimed to clarify the use of PPIs in the evaluation and treatment of children and adults with suspected EoE to develop updated international consensus criteria for EoE diagnosis.

METHODS

A consensus conference was convened to address the issue of PPI use for esophageal eosinophilia using a process consistent with standards described in the Appraisal of Guidelines for Research and Evaluation II. Pediatric and adult physicians and researchers from gastroenterology, allergy, and pathology subspecialties representing 14 countries used online communications, teleconferences, and a face-to-face meeting to review the literature and clinical experiences.

RESULTS

Substantial evidence documented that PPIs reduce esophageal eosinophilia in children, adolescents, and adults, with several mechanisms potentially explaining the treatment effect. Based on these findings, an updated diagnostic algorithm for EoE was developed, with removal of the PPI trial requirement.

CONCLUSIONS

EoE should be diagnosed when there are symptoms of esophageal dysfunction and at least 15 eosinophils per high-power field (or approximately 60 eosinophils per mm²) on esophageal biopsy and after a comprehensive assessment of non-EoE disorders that could cause or potentially contribute to esophageal eosinophilia. The evidence suggests that PPIs are better classified as a treatment for esophageal eosinophilia that may be due to EoE than as a diagnostic criterion, and we have developed updated consensus criteria for EoE that reflect this change.

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.

Diagnostic Trends and Clinical Characteristics of Eosinophilic Esophagitis: A Korean, Single-center Database Study

Background/Aims

The prevalence of eosinophilic esophagitis (EoE) is reportedly increasing in Western countries. However, its prevalence in Korea remains unknown. We investigated the diagnostic trends and clinical characteristics of EoE in Korea.

Methods

Using an endoscopic database maintained at a tertiary care center, we retrospectively reviewed the biopsy reports regarding 18 399 biopsy specimens collected from all patients who underwent esophagogastroduodenoscopy and esophageal biopsy at this facility between 2006 and 2014. The presence of more than 15 eosinophils per high-power field with symptoms related to esophageal dysfunction was considered to indicate EoE.

Results

A total of 37 patients (male:female ratio, 29:8; mean age, 44.0 ± 13.0 years) were diagnosed with EoE. These patients presented with dysphagia (21.6%), epigastric pain (21.6%), heartburn (24.3%), and other symptoms (32.4%). Typical endoscopic appearance of EoE was noted in 33 cases (89.1%) and included linear furrows in 24 cases (64.8%), ringed esophagus in 10 cases (27.0%), and white exudates in 11 cases (29.7%). The median eosinophilic count was 25 per high-power field (interquartile range, 20-70). Notable histopathological findings included eosinophilic microabscesses in 21 cases (56.7%). The diagnosis rate of EoE was found to have increased from 2006 and to 2014 (P-value ＜ 0.001 by the Cochran-Armitage trend test).

Conclusions

The number of patients with EoE appears to have increased significantly over the 9-year period investigated, while the number of endoscopic investigations increased only marginally. Greater awareness of EoE and the role of esophageal biopsies should be considered.

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.

Eosinophilic Esophagitis From an Allergy Perspective: How to Optimally Pursue Allergy Testing & Dietary Modification in the Adult Population

Eosinophilic esophagitis (EoE) is a clinicopathologic condition characterized by symptoms of esophageal dysfunction and eosinophil-predominant inflammation. In adults, the three most common treatment options are swallowed steroids, elimination diets, and periodic esophageal dilations. Many different elimination diets have been studied in adults, including elemental diets, allergy testing-directed diets, and empiric elimination diets. This article will review the existing data on these dietary therapies and will propose an approach to dietary management in adult EoE.

Eosinophilic esophageal myositis diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy: a case report

Eosinophilic esophagitis (EoE) is diagnosed by microscopic findings of eosinophilic infiltration into the squamous epithelium. In contrast, another disease concept termed "eosinophilic esophageal myositis (EoEM)" has been proposed, whereby there is eosinophilic infiltration into the muscularis propria instead. A 60-year-old man was referred to our hospital for chest pain, dysphagia, and several episodes of esophageal food impaction. Although EoE was suspected based on clinical features, biopsy specimens showed no mucosal eosinophilic infiltration. Endoscopic ultrasound (EUS) showed thickening of the muscularis propria layer and subsequent EUS-guided fine-needle aspiration biopsy (EUS-FNA) revealed eosinophilic infiltration into the muscularis propria. Although the patient's symptoms gradually improved after steroid administration, complete remission was not achieved after 1 year of treatment. This case may reflect a disorder distinct from typical EoE based on eosinophilic infiltration of the muscularis propria but not the squamous epithelium, and we, therefore, diagnosed it as EoEM using the EUS-FNA findings as reference.

Meta-Analysis-Based Guidance for Dietary Management in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a prevalent chronic esophageal disorder, triggered and maintained by immunologically mediated responses against dietary antigens. EoE represents the most recent form of food allergy, and its control by avoiding offending foods has increasingly appeared as a therapeutic alternative to achieve and maintain remission. Dietary therapies have proved equally effective in pediatric and adult EoE patients, among whom various types of interventions to eliminate or reduce food antigens exposure have been evaluated. A recent meta-analysis showed elemental diet as the most effective option to induce disease remission, but with a limited application in clinical practice. Inconsistency and wide variability in results from skin allergy testing-directed food restriction contributed to dissatisfaction with implementation of this option, which subsequently was displaced by empiric elimination of common food allergens. Such empiric elimination of common food allergens is now recognized as the best alternative for dietary treatment, with moderate-to-high efficiency and reproducible results. This review provides evidence-based insights into the dietary management of EoE.

A Japanese case of lymphocytic esophagitis

We report the case of a 68-year-old Japanese man diagnosed with lymphocytic esophagitis (LE), a rare disease associated with refractory dysphagia. He has had severe dysphagia and heartburn since 2007. Findings of esophagogastroduodenoscopy (EGD) carried out by a local physician in 2010 showed pale mucosa with white exudate and lateral furrows in the esophagus. He was referred to Tohoku University Hospital in 2012, because the symptoms did not improve, despite regular use of a proton pump inhibitor (PPI). At that time, EGD revealed the coexistence of a slight stricture in the upper esophagus, the histopathological findings of which included a predominantly peri-papillary distribution of abundant, infiltrating CD3⁺ /CD4⁺ /CD8⁺ /CD20^- lymphocytes without any granulocytes (CD4⁺  : CD8⁺  = 3.3:1). These were consistent with a diagnostic criteria of LE. Thereafter, severe dysphagia with food impaction occurred twice a month, despite the long-term use of a PPI, and EGD showed worsened strictures, where endoscopic ultrasonography findings showed marked circumferential thickness of the mucosal and submucosal layers. Then, one session of endoscopic balloon dilatation dramatically improved the dysphagia. Accordingly, LE should be considered an important differential diagnosis of refractory dysphagia based on the characteristic features of endoscopic and pathological findings.

Eosinophilic Esophagitis, Eosinophilic Gastroenteritis, and Eosinophilic Colitis: Common Mechanisms and Differences between East and West

Background

Eosinophilic esophagitis (EoE), eosinophilic gastroenteritis (EGE), and eosinophilic colitis (EoC) have been diagnosed with an increasing frequency over the last decades. All these diseases share pathogenic similarities with respect to triggering by food antigens in the majority of patients once secondary causes of tissue eosinophilia have been excluded. While diagnostic criteria for EoE have been published, the exact criteria for EGE and EoC still need to be defined. This review highlights similarities and differences between affected patients when comparing the Western with the Eastern world.

Summary

The incidence and prevalence of EoE are on the rise in countries from the Western and Eastern world. Very limited epidemiologic data exist regarding EGE and EoC. Characteristics of patients with eosinophilic gastrointestinal disorders regarding gender distribution, age at diagnosis, and associated comorbidities are similar when comparing Eastern with Western countries. Similar modalities are applied to diagnose EoE, EGE, and EoC when comparing Eastern with Western countries. Additionally, comparable therapeutic measures are applied to treat eosinophilic gastrointestinal diseases in Eastern and Western countries. While EoE treatment recommendations are based on increasingly solid evidence, recommendations for the treatment of EGE and EoC are based on low evidence.

Key Messages

Eosinophilic gastrointestinal diseases are diagnosed and treated using similar approaches in Eastern and Western countries. Further efforts should be undertaken to help clarify the underlying pathogenic mechanisms and to establish evidence-based diagnostic and therapeutic protocols.

Systematic review with meta-analysis: the incidence and prevalence of eosinophilic oesophagitis in children and adults in population-based studies

BACKGROUND

The recognition of eosinophilic oesophagitis (EoE) has risen sharply, but its current epidemiology is still under debate.

AIM

To estimate accurately the prevalence and incidence rates of EoE, by a systematic review and meta-analysis.

METHODS

MEDLINE, EMBASE and SCOPUS databases were searched for population-based studies on the epidemiology of EoE. Pooled incidence and prevalence rates, male:female and children:adult ratios, and geographical and temporal variations were calculated with random-effects models.

RESULTS

The search yielded 1334 references; the final quantitative summary included 13 population-based studies from North America, Europe and Australia, with the results showing high heterogeneity. The pooled EoE incidence rate was 3.7/100 000 persons/year [95% confidence interval (CI): 1.7-6.5] and was higher for adults (7; 95% CI: 1-18.3) than for children (5.1; 95% CI: 1.5-10.9). The pooled prevalence of EoE was 22.7 cases/100 000 inhabitants (95% CI: 12.4-36), rising to 28.1 (95% CI: 13-49) when studies with a lower risk of bias were considered; prevalence was higher in adults than in children (43.4; 95% CI: 22.5-71.2 vs. 29.5; 95% CI: 17.5-44.7, respectively), and in American compared to European studies. A steady rise in EoE incidence and prevalence rates was observed upon comparison of studies conducted before and after 2008. No significant publication bias was found.

CONCLUSIONS

Eosinophilic oesophagitis is an increasingly common diagnosis in North America and Europe. The population-based incidence and prevalence of eosinophilic oesophagitis vary widely across individual studies, probably due to variations in diagnosis and risk of bias of research. More prospective, large-scale, multicenter studies are needed to evaluate reported data.

Efficacy of Proton Pump Inhibitor Drugs for Inducing Clinical and Histologic Remission in Patients With Symptomatic Esophageal Eosinophilia: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Proton pump inhibitor (PPI) therapy might lead to clinical and histologic remission in a significant proportion of patients with symptomatic esophageal eosinophilia (>15 eos/high-power field). We aimed to evaluate systematically the efficacy of PPI therapy for these patients.

METHODS

A search in MEDLINE, EMBASE, and SCOPUS databases, and the American Gastroenterological Association Institute, American College of Gastroenterology, and United European Gastroenterology meetings abstract books, was performed. Primary outcomes were clinical response and histologic remission (<15 eos/high-power field) after PPI therapy. Secondary outcomes were the influence on the response to PPIs of age group, study design/quality, PPI type, doses and interval dosing, and pH monitoring results. Data were pooled using a random-effects model.

RESULTS

Thirty-three studies (11 prospective studies) comprising 619 patients with symptomatic esophageal eosinophilia (188 children and 431 adults) were included. PPI therapy led to a clinical response in 60.8% (95% confidence interval, 48.38%-72.2%; I(2) = 80.2) and histologic remission in 50.5% (95% confidence interval, 42.2%-58.7%; I(2) = 67.5) of patients. No differences were observed regarding the study population (children vs adults), the type of publication, or its quality. PPIs were nonsignificantly more effective in prospective studies (52.6% vs 39.1%) administered twice daily compared with once daily (55.9% vs 49.7%), and with pathologic pH monitoring (65.4% vs 49.3%). A significant publication bias in favor of studies reporting histologic responses to PPIs was observed.

CONCLUSIONS

PPI therapy induces clinicohistologic remission in half of patients with symptomatic esophageal eosinophilia. This finding should be interpreted with caution because of poor-quality evidence, heterogeneity, and publication bias.

Systematic review: Eosinophilic esophagitis in Asian countries

AIM: To investigate the prevalence and the clinical characteristics of Asian patients with eosinophilic esophagitis.

METHODS: We conducted a systematic search of the PubMed and Web of Science databases for original studies, case series, and individual case reports of eosinophilic esophagitis in Asian countries published from January 1980 to January 2015. We found 66 and 80 articles in the PubMed and Web of Science databases, respectively; 24 duplicate articles were removed. After excluding animal studies, articles not written in English, and meeting abstracts, 25 articles containing 217 patients were selected for analysis.

RESULTS: Sample size-weighted mean values were determined for all pooled prevalence data and clinical characteristics. The mean age of the adult patients with eosinophilic esophagitis was approximately 50 years, and 73% of these patients were male. They frequently presented with allergic diseases including bronchial asthma, allergic rhinitis, food allergy, and atopic dermatitis. Bronchial asthma was the most frequent comorbid allergic disease, occurring in 24% of patients with eosinophilic esophagitis. Dysphagia was the primary symptom reported; 44% of the patients complained of dysphagia. Although laboratory blood tests are not adequately sensitive for an accurate diagnosis of eosinophilic esophagitis, endoscopic examinations revealed abnormal findings typical of this disease, including longitudinal furrows and concentric rings, in 82% of the cases. One-third of the cases responded to proton pump inhibitor administration.

CONCLUSION: The characteristics of eosinophilic esophagitis in Asian patients were similar to those reported in Western patients, indicating that this disease displays a similar pathogenesis between Western and Asian patients.

Clinical features of eosinophilic esophagitis: differences between Asian and Western populations

The prevalence and incidence of eosinophilic esophagitis (EoE) have been rapidly increasing in Western countries. It is thought to be more common among Caucasians than other racial or ethnic groups, but epidemiological studies have not been fully evaluated in Asian populations, and its clinical manifestation is rarely documented. In this review, recent reports regarding EoE in Asian countries have been collected, and differences in the clinical features, including symptoms and endoscopic findings, between Asian and Western populations have been evaluated. In Asia, EoE is still much less prevalent than in Western countries. Baseline values for average age, male/female ratio, and personal history of allergic disease were comparable to those in Western populations. Predominant symptoms were dysphagia, and food impaction was extremely rare among Asian patients. Although the frequency of abnormal endoscopic findings varies among studies, over 90% of patients with EoE have shown abnormal findings such as linear furrow, which is the most common findings, in recent prospective studies in Asia. There are few reports regarding the treatment of EoE and no prospective studies evaluating drugs or elimination diet in patient with EoE have been reported in Asia. Overall, EoE had similar clinical characteristics in Asian populations. Because the incidence of EoE could increase in the future with the increase in allergic disorders in Asian countries, large-scale, nationwide prospective studies should be performed to more fully understand the epidemiology and pathophysiology of EoE in Asian populations.

Proton-pump inhibitor-responsive esophageal eosinophilia

PURPOSE OF REVIEW

Proton-pump inhibitor-responsive esophageal eosinophilia (PPI-REE) refers to patients showing symptoms and histological findings suggestive of eosinophilic esophagitis (EoE) who achieve complete remission on PPI therapy. This article aims to review evolving evidence on this novel phenotype over the last year.

RECENT FINDINGS

Several prospective series have reported consistent rates of PPI-REE (30-40%) in adults with suspected EoE. At baseline, PPI-REE and EoE have been shown to be indistinguishable upon clinical, endoscopic, and molecular characteristics [eotaxin-3, interleukin (IL-5), and IL-13 expression]. PPI therapy partially restores esophageal mucosal integrity in PPI-REE, but not in EoE. Anti-inflammatory effects of PPI therapy, independent of acid suppression, have been confirmed in EoE and gastroesophageal reflux disease cell cultures. PPI therapy in vivo downregulates Th2 cytokines in PPI-REE patients, in a similar fashion to that seen in steroid-responsive EoE.

SUMMARY

PPI-REE has emerged as a common clinical phenotype. PPI-REE and EoE remain largely indistinguishable, suggesting that they might be the same disease at baseline. While PPI therapy has been demonstrated to partially restore epithelial integrity in PPI-REE, in-vitro and in-vivo studies suggest that the anti-inflammatory effects of PPI therapy may be responsible for this restoration through inhibition of the Th2-allergic pathway rather than only acid suppression.

Limited role of allergy testing in patients with eosinophilic gastrointestinal disorders

BACKGROUND AND AIM

Allergies have been implicated in the pathogenesis of eosinophilic gastrointestinal disorders, although it remains unknown what type of allergen is closely associated with their development. The aim of this study is to investigate the possible involvement of food and/or aeroallergen factors in eosinophilic gastrointestinal disorders.

METHODS

Eighteen patients with eosinophilic esophagitis (EoE), 23 with eosinophilic gastroenteritis (EGE), and 28 healthy volunteers were enrolled. The levels of total serum immunoglobulin E (IgE) and 33 different allergen-specific IgE antibodies, including those for six foods used in a standard EoE elimination diet, were determined in each subject. Serum antigen-specific IgE levels were measured using a chemiluminescence enzyme immunoassay with a multiple antigen simultaneous test 33 (MAST33). The expression patterns of specific antigens were compared among the groups.

RESULTS

The mean level of total IgE antibodies was significantly higher in patients with EGE (553.6 ± 115.3 IU/mL) than the healthy volunteers (230.6 ± 87.1 IU/mL). Two thirds of all subjects had sensitivity to at least one inhaled antigen. In positive cases, allergies against multiple antigens were more frequently seen in the EoE and EGE patients. Japanese cedar and dust mite aeroallergens were more prevalent than food antigens.

CONCLUSIONS

Consistent with higher levels of serum total IgE antibodies, patients with EoE and EGE were frequently sensitized to several different allergens. Reactions to aeroallergens were more prevalent in these groups, although no particular antigen causing EoE and/or EGE was detected by measuring serum antigen-specific IgE antibodies.

Review article: proton pump inhibitor therapy for suspected eosinophilic oesophagitis

BACKGROUND

Recent advances in eosinophilic oesophagitis (EoE) have confirmed the existence of a new disease phenotype, proton pump inhibitor (PPI)-responsive oesophageal eosinophilia (PPI-REE).

AIM

To summarise evidence supporting the use of PPI therapy in patients with suspected EoE (oesophageal dysfunction plus >15 eos/HPF in oesophageal biopsies).

METHODS

A literature search was conducted through MEDLINE, using the MeSH search terms 'eosinophilic oesophagitis', 'proton pump inhibitors' and 'oesophageal eosinophilia'. Relevant articles and their reference lists were identified through manual review.

RESULTS

Ten articles, including 258 patients with suspected EoE (152 children, 106 adults) undergoing clinico-histological re-evaluation after PPI therapy, were identified. In children, clinical response ranged from 78% to 86% and histological remission from 23% to 40%. In adults, symptom response ranged from 25% to 80% and histological remission from 33% to 61%. Among PPI-REE patients with oesophageal pH-monitoring, 35 showed pathological and 10 normal studies. PPI-REE was significantly commoner with documented gastro-oesophageal reflux disease (GERD) when compared to patients with negative pH monitoring (70% vs. 29%, P < 0.001). Symptom improvement/resolution occurred in 50-85% of patients without histological remission on PPI therapy. Six PPI-REE patients demonstrated clinico-histological relapse on PPI therapy.

CONCLUSIONS

At least one third of patients with suspected EoE achieve clinico-histological remission on PPI therapy. Response is more limited in children compared with that in adults. pH monitoring does not accurately predict response to PPI therapy, albeit histological remission is significantly higher, up to 70%, upon documented GERD. Symptom improvement is common with PPI therapy despite persistent eosinophilic infiltration.