Proton pump inhibitor (PPI) therapy results in clinical and histological remission in approximately 50% of eosinophilic esophagitis (EoE) patients. We aimed to systematically update this topic due to cumulative data from pediatric/adult populations in wider geographical settings.

A search in MEDLINE, Embase, and Scopus databases was performed. Primary outcomes were clinical response and histological remission (<15 eosinophils per high-power field). Subgroup analyses included age group, PPI drug and dosage, study design, data origin, and risk of bias. Data were pooled using random-effects models.

Seventy-three studies comprising 7304 patients were included. PPI therapy led to clinical response in 65% (95% confidence interval [CI], 57.2-72.4; I2 = 0%) and histological remission in 45.4% (95% CI, 41.6%-49.3%) of patients, without differences between children and adults (41.2% vs 48%; P ••• .17). Overall, 34.1% (95% CI, 27.9%-40.5%) achieved <5 eosinophils per high-power field. Pooled effectiveness was significantly superior (P < .001) in Western Pacific areas, principally Japan (67.9%), compared with American and European areas (40.6% and 44.4%, respectively). Histological remission was significantly higher with double PPI doses compared with standard (51.7% vs 28.3%; P •••.005). Response was significantly higher in studies with lower risk of bias. Maintenance half-doses led to sustained histological remission in 68.2% (95% CI, 63.7%-72.6%; I2 = 0%) of patients.

PPI therapy induces clinic-histological remission in almost half of pediatric and adult EoE patients. Response to PPIs is significantly higher in Japan. Sustained remission is common on tapering PPI doses.

Background: Eosinophilic esophagitis (EoE) is a disease characterized by eosinophilic inflammation of the esophagus and associated esophageal dysfunction with increasing worldwide prevalence. Clinical presentation is nonspecific and varies with age, with limited studies in the pediatric population. Objective: Our study aimed to compile clinical phenotypes, esophagogastroduodenoscopy findings, and treatment response of EoE in a tertiary pediatric center, and to examine factors associated with the response of treatment. Methods: In this retrospective study, we reviewed the medical records of 824 patients diagnosed with EoE at Children's Hospital of Michigan from 2011 to 2021. Data collected included a demographic profile, symptoms, esophagogastroduodenoscopic and histopathologic findings, treatment modalities, response, and compliance. We then performed a multivariable logistic regression to assess the associating factors that influenced the treatment response rate. Results: A high proportion of males and coexisting allergic conditions were observed in the patients with EoE, with the most common presentation of vomiting in children and of abdominal pain in adolescents. Among 656 of the 824 patients who had follow-up esophagogastroduodenoscopy, treatment response rates varied among modalities, with proton-pump inhibitor treatment exhibiting the highest response rate, at 60.8%, followed by diet modification (50%) and topical steroid treatment (43.5%). Significant predictors of normal endoscopic findings at follow-up included female gender, normal endoscopic appearance, good compliance to treatment, and absence of topical steroids in the treatment regimen. There were no significant differences in outcomes observed for targeted elimination led by a skin-prick test or specific immunoglobulin E test. Medication compliance did not significantly differ among the treatment options. Conclusion: Managing EoE in pediatric patients poses significant challenges, which emphasizes the need for multidisciplinary care to achieve treatment response effectively. The findings underscore the complexity of managing EoE and the need for individualized treatment approaches. Further research is warranted to elucidate the underlying mechanisms and optimize management strategies for pediatric patients with EoE.

Proton pump inhibitors (PPIs) are one of the standards of care of eosinophilic esophagitis (EoE) treatment, though PPI response rates are variable ranging from 23 to 63% in pediatric studies. We sought to determine if expression of select genes in esophageal mucosa can predict PPI responsiveness in EoE. Children with a new diagnosis of EoE (15 or more eosinophils/hpf on esophageal biopsy) were prospectively treated with 8 weeks of PPI therapy before follow-up esophagogastroduodenoscopy (EGD). Children with <15 eosinophils/hpf on follow-up were classified as having PPI-Responsive EoE (PPI-R) and ≥ 15 eosinophils/hpf as PPI-Nonresponsive EoE (PPI-NR). Using the Nanostring nCounter Analysis System, mRNA expression of a custom panel of genes was measured in esophageal biopsies. Immunohistochemical staining of biopsies was performed. Among children with EoE, 32% (8/25) had PPI-R EoE. ATP12A, ATP4A, tryptase-beta 2 (TPSB2), CLC and IL13 had higher expression in PPI-NR EoE compared to PPI-R EoE or controls. Immunohistochemical staining of ATP12A was higher among PPI-R EoE and PPI-NR EoE, compared to non-EoE controls. In this study, PPI-NR EoE had significantly higher baseline gene expression of mast cell, cytokine, proton pump, and eosinophil genes compared to PPI-R EoE. PPIs may be involved in an inflammatory cascade of mast cell activation that stimulates IL-13 release, which upregulates ATP12A and ATP4A that leads to eosinophil recruitment. Histologic PPI failure may occur when increased gene expression of these components is high and cannot be overcome pharmacologically, especially in the case of proton pump genes.

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus characterized by symptoms of esophageal dysfunction and histologically by predominantly eosinophilic infiltration of the squamous epithelium. European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) published a guideline in 2014; however, the rapid evolution of knowledge about pathophysiology, diagnostic criteria, and therapeutic options have made an update necessary.

A consensus group of pediatric gastroenterologists from the ESPGHAN Working Group on Eosinophilic Gastrointestinal Diseases (ESPGHAN EGID WG) reviewed the recent literature and proposed statements and recommendations on 28 relevant questions about EoE. A comprehensive electronic literature search was performed in MEDLINE, EMBASE, and Cochrane databases from 2014 to 2022. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess the quality of evidence and formulate recommendations.

A total of 52 statements based on the available evidence and 44 consensus-based recommendations are available. A revision of the diagnostic protocol, options for initial drug treatment, and the new concept of simplified empiric elimination diets are now available. Biologics are becoming a part of the potential armamentarium for refractory EoE, and systemic steroids may be considered as the initial treatment for esophageal strictures before esophageal dilation. The importance and assessment of quality of life and a planned transition to adult medical care are new areas addressed in this guideline.

Research in recent years has led to a better understanding of childhood EoE. This guideline incorporates the new findings and provides a practical guide for clinicians treating children diagnosed with EoE.

The present document constitutes Part 2 of the EoETALY Consensus Statements guideline on the diagnosis and management of eosinophilic esophagitis (EoE) developed by experts in the field of EoE across Italy (i.e., EoETALY Consensus Group). Part 1 was published as a different document, and included three chapters discussing 1) definition, epidemiology, and pathogenesis; 2) clinical presentation and natural history and 3) diagnosis of EoE. The present work provides guidelines on the management of EoE in two final chapters: 4) treatment and 5) monitoring and follow-up, and also includes considerations on knowledge gaps and a proposed research agenda for the coming years. The guideline was developed through a Delphi process, with grading of the strength and quality of the evidence of the recommendations performed according to accepted GRADE criteria.This document has received the endorsement of three Italian national societies including the Italian Society of Gastroenterology (SIGE), the Italian Society of Neurogastroenterology and Motility (SINGEM), and the Italian Society of Allergology, Asthma, and Clinical Immunology (SIAAIC). The guidelines also involved the contribution of members of ESEO Italia, the Italian Association of Families Against EoE.

The optimal proton pump inhibitor (PPI) regimen for eosinophilic esophagitis (EoE) is unclear. We compared histologic response rates of different dosing combinations.

A total of 305 patients with newly diagnosed EoE received standard (omeprazole 20 mg daily), once-daily moderate (40 mg daily), twice-daily moderate (20 mg twice daily), or high (40 mg twice daily) dose PPI for ≥8 weeks.

Approximately 42.3% achieved histologic response to PPI, with higher rates for twice-daily (moderate 52.8%/high 54.3%) than once-daily (standard 11.8%/moderate 10%) dosing ( P < 0.0001). On multivariable analysis, twice-daily moderate (adjusted odds ratio 6.75, confidence interval 2.53-18.0, P = 0.0008) and high (adjusted odds ratio 12.8, confidence interval 4.69-34.8, P < 0.0001) doses independently predicted histologic response.

Twice-daily PPI is associated with higher EoE histologic response rates than once-daily regimen.

Eosinophilic gastrointestinal diseases (EGIDs) are chronic, immune-mediated disorders characterised clinically by gastrointestinal symptoms and histologically by a pathologic increase in eosinophil-predominant inflammation in the gastrointestinal tract, in the absence of secondary causes of eosinophilia.

To highlight emerging insights and research efforts into the epidemiology, pathophysiology, diagnostic and therapeutic aspects of eosinophilic oesophagitis (EoE) and non-EoE EGIDs, and discuss key remaining knowledge gaps.

We selected and reviewed original research, retrospective studies, case series, randomised controlled trials, and meta-analyses.

Standardised nomenclature classifies EGIDs as EoE, eosinophilic gastritis (EoG), eosinophilic enteritis (EoN), and eosinophilic colitis (EoC). Incidence and prevalence of EoE are rising, emphasising the need to better understand how environmental risk factors and genetic features interact. Advances in understanding EoE pathophysiology have led to clinical trials of targeted therapy and the approval (in the United States) of dupilumab for EoE. Several therapies that are under investigation hope to satisfy both histologic and clinical targets. For non-EoE EGIDs, efforts are focused on better defining clinical and histopathologic disease determinants and natural history, as well as establishing new therapies.

Unmet needs for research are dramatically different for EoE and non-EoE EGIDs. In EoE, non-invasive diagnostic tests, clinicopathologic models that determine the risk of disease progression and therapeutic failure, and novel biologic therapies are emerging. In contrast, in non-EoE EGIDs, epidemiologic trends, diagnostic histopathologic thresholds, and natural history models are still developing for these more rare disorders.

To assess the short- and long-term efficacy of proton pump inhibitor (PPI) therapy for pediatric eosinophilic esophagitis (EoE) in real-world practice with a step-down strategy, and to evaluate factors predictive of PPI responsiveness.

We collected data regarding the efficacy of PPIs during this cross-sectional analysis of the prospective nationwide RENESE registry. Children with EoE treated with PPI monotherapy were included. Histological remission was defined as a peak eosinophilic count of <15 eosinophils (eos)/high-power field (hpf). Factors associated with PPI responsiveness were identified using multivariate logistic regression analysis.

After induction therapy, histological and clinico-histological remission were observed in 51.4% (n = 346) and 46.5% of children, respectively. Normal endoscopic appearance of the esophagus was associated with a higher possibility [odds ratio (OR), 9.20; 95% confidence interval (CI), 2.10-40.16], and fibrostenotic phenotype was associated with a lower possibility (OR, 0.36; 95% CI, 0.18-0.74) of histological remission. Long-term therapy with a step-down strategy effectively maintained histological remission in 68.5% and 85.3% of children at 7 months (n = 108) and 16 months (n = 34), respectively. Complete initial histological remission (≤5 eos/hpf) was associated with a higher possibility of sustained histological remission (OR, 5.08; 95% CI, 1.75-14.68). Adverse events were infrequent and mild.

We confirmed the efficacy of PPIs for a large cohort of children with EoE with sustained histological remission using a step-down strategy. Children with fibrostenotic phenotypes are less likely to respond to induction therapy. Furthermore, patients with complete initial histological remission are more likely to experience long-term histological remission.

Eosinophilic esophagitis (EoE) is an emerging chronic inflammatory disease of the oesophagus and is clinically characterized by upper gastrointestinal (GI) symptoms including dysphagia and esophageal food impaction. Histopathologic manifestations, which include intraepithelial eosinophilic inflammation and alterations of the esophageal squamous epithelium, such as basal zone hyperplasia (BZH) and dilated intercellular spaces (DIS), are thought to contribute to esophageal dysfunction and disease symptoms. Corroborative clinical and discovery science-based studies have established that EoE is characterized by an underlying allergic inflammatory response, in part, related to the IL-13/CCL26/eosinophil axis driving dysregulation of several key epithelial barrier and proliferative regulatory genes including kallikrein (KLK) serine proteases, calpain 14 (CAPN14) and anoctamin 1 (ANO1). The contribution of these inflammatory and proliferative processes to the clinical and histological manifestations of disease are not fully elucidated. Herein, we discuss the immune molecules and cells that are thought to underlie the clinical and pathologic manifestations of EoE and the emerging therapeutics targeting these processes for the treatment of EoE.

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.

Identification of clinical predictors of response to first-line therapies for EoE is needed to guide initial medical management.

A retrospective analysis of patients diagnosed with EoE from 2011 to 2018 was conducted. Clinical and diagnostic variables including demographics, endoscopic, and esophagram findings were compared between PPI responders and PPI nonresponders. All patients underwent a standard 8-week twice-daily PPI trial, with PPI responsiveness defined as < 15 eos/hpf on repeat EGD. Univariate and multivariable analyses were conducted to identify risk factors for nonresponse, and ROC curves were created to identify cutoff values.

A total of 223 EoE patients (135 male, median age 39 (29-51)) were identified, with PPI nonresponse (PPI-NR) in 71% of patients. PPI-NR was seen in all 10 patients with failure of scope passage, with an OR of 9.06 by univariate analysis (P = 0.1485). In a multivariable model, age per 10 years (OR 0.71; P = 0.007), BMI per 1 kg/m² (OR 0.94; P = 0.03), and peripheral eosinophil count per 100 per mm³ (OR 1.37; P = 0.003) were independent risk factors. Dichotomization to maximize sensitivity and specificity identified age ≤ 36 years old, BMI ≤ 25.2 kg/m², and peripheral eos > 460 per mm³ as predictive thresholds for PPI-NR. The probability of PPI-NR was 72.4-84.5% with 1 risk factor, 87.9-93.8% with 2 risk factors, and 97.2% with all 3 risk factors.

Young age, reduced BMI, elevated peripheral eosinophil count, and likely inability to pass an endoscope predict lack of response to PPIs in patients with EoE.

Background and study aim  The clinical impact of eosinophilic esophagitis (EoE) limited to the distal esophagus (Lim-EE) vs. diffuse involvement (Dif-EE) is unknown. This study compared clinical characteristics and outcomes of Lim-EE vs. Dif-EE. Patients and methods  This retrospective, single-center study of patients with EoE between December 2011 and December 2019 evaluated treatment response based on repeated pathology and/or clinical improvement using comparative statistics. Results  479 patients were identified (126 Lim-EE, 353 Dif-EE). Lim-EE patients had a higher incidence of endoscopically identified esophagitis (23.0 % vs. 14.7 %; P  = 0.04), were older (50.8 [SD 16.2] vs. 46.4 [SD 15.3] years; P  = 0.007), and were more likely to present with iron deficiency anemia (5.6 % vs. 1.7 %; P  = 0.05), dyspepsia (15.1 % vs. 8.8 %; P  = 0.06) or for Barrett's surveillance (10.3 % vs. 3.7 %; P  = 0.02). Patients with Dif-EE presented more frequently with dysphagia (57.2 % vs. 45.2 %; P  = 0.02). Both groups had similar proton pump inhibitor (87.2 % vs. 83.3 %; P  = 0.37) and steroid (12.8 % vs. 21.4 %; P  = 0.14) use. Patients with Lim-EE had a better clinicopathologic response (61.5 % vs. 44.8 %; P  = 0.009). On multivariate analysis, EoE extent predicted treatment response with an odds ratio of 1.89 (95 % confidence interval 1.13-3.20; P  = 0.02). However, treatment response based only on repeat biopsy results showed no statistical difference between Lim-EE (52.5 %) and Dif-EE (39.7 %; P  = 0.15). Conclusions  Lim-EE may represent a distinct phenotype separate from Dif-EE, with more overlap with gastroesophageal reflux disease and better treatment response.

Eosinophilic esophagitis (EoE) is a chronic allergic disease with esophageal symptoms and intraepithelial eosinophil infiltration. Effects of potassium-competitive acid blockers (P-CABs) on EoE have not been elucidated. We aimed to examine and compare the effects of P-CABs and PPIs on symptomatic, endoscopic, and histological responses of patients with EoE.

We analyzed 118 EoE patients who received PPI or P-CAB therapy with rabeprazole 10 mg (RPZ10, N = 22), rabeprazole 20 mg (RPZ20, N = 34), esomeprazole 20 mg (EPZ20, N = 25), or vonoprazan 20 mg (VPZ20, N = 33). We evaluated symptomatic responses by classifying the patients into three groups: complete relief, partial relief, and no change. Endoscopic responses were evaluated using the endoscopic reference score (EREFS) following PPI or P-CAB therapy. Histological responses were evaluated by determining eosinophil counts in esophageal biopsy samples and classifying the patients into two groups: complete remission [0/1 eosinophil/high-power field (eos/HPF)] and remission (< 15 eos/HPF).

There were no differences among the therapy groups in terms of clinical characteristics, endoscopic findings, and histological findings of the patients before treatment. The rate of complete relief in clinical symptoms was 54.5% in the RPZ10 group, 64.7% in the RPZ20 group, 72.0% in the EPZ20 group, and 75.7% in the VPZ20 group. There were no significant differences in the therapeutic effect among the therapy groups. Similarly, endoscopic and histological complete remission rates were not significantly different among the therapy groups.

Vonoprazan showed similar efficacy to PPIs in EoE.

Eosinophilic esophagitis (EoE) is an allergen-driven chronic inflammatory condition, characterized by symptoms related to esophageal dysfunction and confirmed histologically by esophageal mucosal eosinophilia. Since its first description in the 1990s, the incidence and prevalence of EoE have been on the rise. It is known to affect all ages of various ethnic backgrounds and both sexes; however, it is most seen in White males. Children with EoE often present with abdominal pain, nausea, vomiting, and failure to thrive, whereas adults with EoE typically present with dysphagia and food impaction. Diagnosis of EoE requires histologic confirmation of elevated esophageal eosinophils in a symptomatic patient, and only after secondary causes have been excluded. Because EoE is a chronic and progressively fibrostenotic disease, treatment goals include resolution of symptoms, induction and maintenance of disease remission, and prevention and possibly reversal of fibrostenotic complications, while minimizing treatment-related adverse effects and improving quality of life. Treatment strategies include the "3 D's"-drugs, diet, and dilation. Standard drug therapies include proton-pump inhibitors and topical corticosteroids. Dietary therapies include elemental diet, allergy testing-directed elimination diet, and empiric elimination diets. Endoscopic esophageal dilation for EoE strictures can alleviate esophageal symptoms but has no effect on mucosal inflammation. Recent progress in EoE research has made possible evidence-based clinical guidelines. Ongoing pharmacologic trials show promise for novel biologic agents in the treatment of refractory EoE.

The aim of this review is to describe the role of precision medicine in the diagnosis, treatment, and monitoring of cow's milk allergy.

The development of 'omics' sciences in the field of food allergy has led to a better understanding of the allergenicity of cow's milk proteins and significant advances in the knowledge of the pathogenesis and mechanisms of cow's milk allergy. Omics-based technologies allow the practitioner to better differentiate cow's milk allergy subtypes and to predict cow's milk allergy (CMA) persistence over time. Precision medicine extends the role of the oral food challenge, to determine the individual's threshold doses, and to establish tolerance to baked milk products. Other than symptom relief, dietary strategies are currently being investigated for the potential to induce tolerance. Oral immunotherapy offers a treatment option for patients with severe and persistent IgE-mediated CMA. Individual baseline-immune profiles may be predictive of cow's milk oral immunotherapy safety and efficacy.Patient data derived from current technology, in combination with the patient's history, can be translated into treatments targeted at patient-tailored interventions.

The identification of novel biomarkers may improve diagnostic accuracy and also predict patient responsiveness to treatments. Integration of patient data will become increasingly important as omics technologies become more widely used in the clinical setting.

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition of the esophagus. Many new studies have been reported recently that describe EoE management. An expert panel was convened by the American Gastroenterological Association Institute and the Joint Task Force on Allergy-Immunology Practice Parameters to provide a technical review to be used as the basis for an updated clinical guideline. This technical review was developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. Eighteen focused EoE management questions were considered, with 15 answered using the GRADE framework and 3 with a narrative summary. There is moderate certainty in the evidence that topical glucocorticosteroids effectively reduce esophageal eosinophil counts to <15 per high-power field over a short-term treatment period of 4-12 weeks, but very low certainty about the effects of using topical glucocorticosteroids as maintenance therapy. Multiple dietary strategies may be effective in reducing esophageal eosinophil counts to <15 per high-power field over a short-term treatment period, with moderate certainty for elemental diets, low certainty for empiric 2-, 4-, and 6-food elimination diets, and very low certainty that allergy-based testing dietary eliminations have a higher failure rate compared to empiric diet elimination. There is very low certainty for the effect of proton pump inhibitors in patients with esophageal eosinophilia. Although esophageal dilation appears to be relatively safe, there is no evidence that it reduces esophageal eosinophil counts. There is very low certainty in the effects of multiple other medical treatments for EoE: anti-interleukin-5 therapy, anti-interleukin-13 therapy, anti-IgE therapy, montelukast, cromolyn, and anti-TNF therapy.

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition of the esophagus. Many new studies have been reported recently that describe EoE management. An expert panel was convened by the American Gastroenterological Association Institute and the Joint Task Force on Allergy-Immunology Practice Parameters to provide a technical review to be used as the basis for an updated clinical guideline. This technical review was developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. Eighteen focused EoE management questions were considered, with 15 answered using the GRADE framework and 3 with a narrative summary. There is moderate certainty in the evidence that topical glucocorticosteroids effectively reduce esophageal eosinophil counts to <15 per high-power field over a short-term treatment period of 4-12 weeks, but very low certainty about the effects of using topical glucocorticosteroids as maintenance therapy. Multiple dietary strategies may be effective in reducing esophageal eosinophil counts to <15 per high-power field over a short-term treatment period, with moderate certainty for elemental diets, low certainty for empiric 2-, 4-, and 6-food elimination diets, and very low certainty that allergy-based testing dietary eliminations have a higher failure rate compared to empiric diet elimination. There is very low certainty for the effect of proton pump inhibitors in patients with esophageal eosinophilia. Although esophageal dilation appears to be relatively safe, there is no evidence that it reduces esophageal eosinophil counts. There is very low certainty in the effects of multiple other medical treatments for EoE: anti-interleukin-5 therapy, anti-interleukin-13 therapy, anti-IgE therapy, montelukast, cromolyn, and anti-TNF therapy.

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

Management of eosinophilic esophagitis (EoE) varies from center to center. In this study, we evaluated the effectiveness of a dairy-free diet (DFD) and the 6-Food Elimination Diet (SFED) as initial therapies for the treatment of EoE in our practice.

This was a retrospective study of children who had been treated for EoE at Connecticut Children's Medical Center, Hartford, CT, USA. Pre- and post-treatment endoscopy findings and histology results of patients treated with DFD or SFED were examined.

One hundred fifty-two patients (age 9.2±5.2 years, 76.3% male, 69.7% caucasian) met the inclusion criteria for initial treatment with DFD (n=102) or SFED (n=50). Response for DFD was 56.9% and for SFED was 52.0%. Response based on treatment duration (<10, 10-12, and >12 weeks) were 81.8%, 50.0%, and 55.1% for DFD, and 68.8%, 50.0%, and 40.0% for SFED. Response based on age (<6, 6-12, and >12 years) were 59.3%, 42.9%, and 67.5% for DFD, and 36.4%, 58.8%, and 72.7% for SFED. In patients treated with DFD, concomitant proton pump inhibitor (PPI) administration resulted in improved outcomes (p=0.0177). Bivariate regression analysis showed that PPI with diet is the only predictor of response (p=0.0491), however, there were no significant predictors on multiple regression analysis.

DFD and SFED are effective first line therapies for EoE. DFD should be tried first before extensive elimination diets. Concomitant therapy with PPI's may be helpful.

Eosinophilic esophagitis is an immune-allergic pathology of multifactorial etiology (genetic and environmental) that affects both pediatric and adult patients. Its symptoms, which include heartburn, regurgitation, and esophageal stenosis (with dysphagia being more frequent in eosinophilic esophagitis in young adults and children), are similar to those of gastroesophageal reflux disease, causing delays in diagnosis and treatment. Although endoscopic findings such as furrows, esophageal mucosa trachealization, and whitish exudates may suggest its presence, this diagnosis should be confirmed histologically based on the presence of more than 15 eosinophils per high-power field and the exclusion of other causes of eosinophilia (parasitic infections, hypereosinophilic syndrome, inflammatory bowel disease, among others) for which treatment could be initiated. Currently, the 3 "D"s ("Drugs, Diet, and Dilation") are considered the fundamental components of treatment. The first 2 components, which involve the use of proton pump inhibitors, corticosteroids, immunosuppressants and empirical diets or guided food elimination based on allergy tests, are more useful in the initial phases, whereas endoscopic dilation is reserved for esophageal strictures. Herein, the most important aspects of eosinophilic esophagitis pathophysiology will be reviewed, in addition to evidence for the various treatments.

Esophageal eosinophilia occurs in many conditions, including eosinophilic esophagitis (EoE) and proton pump inhibitor-responsive esophageal eosinophilia (PPI-REE), which have been increasingly recognized in Western countries. There have been only a few reports in Korea. Here, we evaluated the clinical and endoscopic characteristics of patients with esophageal eosinophilia from our experience.

Nineteen patients were diagnosed with esophageal eosinophilia based on typical symptoms, endoscopic features, esophageal eosinophilia with ≥15 eosinophils/high power field, and response to medication by PPI. Symptoms, endoscopic and pathological findings were evaluated.

Of the 19 patients, 2 patients were diagnosed with EoE, 7 patients were diagnosed with PPI-REE, and 10 patients were undetermined due to loss to follow-up. Among these 19 patients, dysphagia was present in 11, and heartburn, dyspepsia and refluxin 8. Sixteen patients had common endoscopic features, such as longitudinal furrows, concentric rings, strictures, and white plaques; however, 3 patients had normal findings. Nine patients underwent endoscopy at the time of follow-up. Two patients had complete resolution, and 3 had partial resolution. However, 4 patients showed no endoscopic changes. All patients showed symptom improvements.

The clinical and endoscopic characteristics of both groups in Korea were undistinguishable. However, after treatment, endoscopic findings were different between the two groups. Large-scale studies are warranted to confirm our findings.

Recent studies have reported a higher prevalence of eosinophilic esophagitis in children with esophageal atresia. Under recognition of eosinophilic esophagitis in these patients may lead to excessive use of antireflux therapy and an escalation of interventions, including fundoplication, as symptoms may be attributed to gastroesophageal reflux disease. In addition, long-term untreated eosinophilic esophagitis may lead to recurrent strictures due to transmural esophageal inflammation, necessitating repeated dilatations. Eosinophilic esophagitis should be considered when children with esophageal atresia show persistent symptoms on standard antireflux treatment, increasing dysphagia, and recurrent strictures. Treatment has been found to not only significantly reduce intraepithelial eosinophil count, but also to improve symptoms, and to lower the occurrence of strictures and the need for dilatations. Future prospective studies are warranted in this area.

Eosinophilic esophagitis and asthma are frequently found as comorbid conditions in children and adults along with other manifestations of atopic diathesis. These two conditions have similar T helper 2 responses-driven pathophysiology and share common management strategies such as using systemic corticosteroids and targeted anti-cytokine biologic therapies. Review of the literature finds that asthma is often a comorbid condition in eosinophilic esophagitis in both children and adults; however, the EoE-asthma relationship remains poorly characterized mechanistically and clinically. EoE and asthma commonly share several comorbid conditions such as allergic rhinitis and gastroesophageal reflux disease; therefore, addressing these comorbid conditions has the potential to improve and/or maintain control in both diseases. Similar to asthma, patients with EoE frequently demonstrate elevations in serum markers of atopy, including serum IgE levels, peripheral eosinophil counts, and T helper 2-related cytokines. Gastroesophageal reflux disease is thought to affect asthma through microaspirations, airway hyperresponsiveness, and increased vagal tone. The understanding of the relationship between gastroesophageal reflux and EoE is still evolving but seems to be bidirectional and interactive. In terms of treatment, similar classes of medications have been used in both EoE and asthma. In both children and adults, EoE remission can be achieved by food trigger avoidance and use of corticosteroids and biologic therapies. Asthma control is mostly achieved through inhaled corticosteroids, and long but biologic therapies are increasingly used in severe subsets of the disease. Significant clinical and mechanistic work needs to be accomplished to better understand the relationship between asthma, EoE, and their interaction with other allergic diseases. Understanding whether shared mechanisms exist can lead to the development of new diagnostic and therapeutic strategies. The following review examines the existing literature regarding prevalence, common comorbidities, and potential therapeutic approach and identifies gaps in knowledge and future directions.

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.

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.

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.

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.

Although current American guidelines distinguish proton pump inhibitor-responsive oesophageal eosinophilia (PPI-REE) from eosinophilic oesophagitis (EoE), these entities are broadly similar. While two microarray studies showed that they have similar transcriptomes, more extensive RNA sequencing studies have not been done previously.

To determine whether RNA sequencing identifies genetic markers distinguishing PPI-REE from EoE.

We retrospectively examined 13 PPI-REE and 14 EoE biopsies, matched for tissue eosinophil content, and 14 normal controls. Patients and controls were not PPI-treated at the time of biopsy. We did RNA sequencing on formalin-fixed, paraffin-embedded tissue, with differential expression confirmation by quantitative polymerase chain reaction (PCR). We validated the use of formalin-fixed, paraffin-embedded vs RNAlater-preserved tissue, and compared our formalin-fixed, paraffin-embedded EoE results to a prior EoE study.

By RNA sequencing, no genes were differentially expressed between the EoE and PPI-REE groups at the false discovery rate (FDR) ≤0.01 level. Compared to normal controls, 1996 genes were differentially expressed in the PPI-REE group and 1306 genes in the EoE group. By less stringent criteria, only MAPK8IP2 was differentially expressed between PPI-REE and EoE (FDR = 0.029, 2.2-fold less in EoE than in PPI-REE), with similar results by PCR. KCNJ2, which was differentially expressed in a prior study, was similar in the EoE and PPI-REE groups by both RNA sequencing and real-time PCR.

Eosinophilic oesophagitis and PPI-REE have comparable transcriptomes, confirming that they are part of the same disease continuum.

Eosinophilic esophagitis (EoE) is a unique form of non-IgE-mediated food allergy characterized by esophageal eosinophilic infiltration that commonly causes dysphagia and food impaction in children and adolescents. Assessing the efficacy of dietary restrictions or drug therapies to achieve clinical and histologic resolution of EoE through randomized controlled trials and meta-analyses has resulted in new evidence-based guidelines. Avoiding food triggers is the only therapy targeting the cause of the disease. None of the currently available food allergy tests adequately predict food triggers for EoE. Exclusively feeding with an amino acid-based elemental diet and empiric six-food elimination diet (avoiding the six foods most commonly related with food allergy) has consistently provided the best cure rates, but their high level of restriction and need for multiple endoscopies are deterrents for implementation. Simpler and less restrictive empirical methods, like a four-food (milk, gluten-containing cereals, egg, legumes) or a two-food (milk and gluten) elimination diet, show encouraging results. Proton pump inhibitors are currently a first-line treatment, achieving histological remission and improvement of symptoms in 54.1 and 64.9% of pediatric EoE patients, respectively. The efficacy of topical corticosteroids in EoE assessed in several trials and summarized in meta-analyses indicates that budesonide and fluticasone propionate are significantly superior to placebos, both in decreasing eosinophil mucosal infiltration and in relieving symptoms. Owing to differences in drug delivery, viscous budesonide formulas seem to be the best pharmacological therapy for EoE.

Applying evidence-based therapies and a practical management algorithm provide an effective control of EoE. What is Known: • Eosinophilic esophagitis (EoE) now constitutes the main cause of dysphagia and food impaction in children, adolescents, and young adults. • Its chronic course and frequent progression to subepithelial fibrosis leading to strictures and narrow-caliber esophagus indicate the need for treatment. What is New: • Therapeutic goals in children with EoE include resolution of esophageal symptoms, to cure esophageal inflammation (mucosal healing) and restore a proper esophageal caliber in case of fibrostenotic endoscopic findings. Avoiding iatrogenic drug effects and nutritional deficiencies, as well as maintaining an adequate quality of life, is also essential. • Novel evidence-based guidelines, endorsed by several European scientific societies, incorporate recent advances in knowledge from several randomized controlled trials and systematic reviews to provide the best standard of care to pediatric patients, by following simple management algorithms.

Eosinophilic esophagitis (EoE) is treated with dietary modification and/or pharmacologic management with swallowed topical steroids. Swallowed fluticasone propionate (FP) and oral viscous budesonide (OVB) have proven to be effective in resolving symptoms and reversing histologic changes in children and adults with EoE. There are minimal comparative studies between the 2 agents.

The aim of the study was to retrospectively compare endoscopic and histologic outcomes after FP versus OVB therapy in children with EoE in our center.

We performed a retrospective chart review of subjects diagnosed with EoE at a tertiary care center between 2010 and 2015. Inclusion criteria were FP or OVB therapy for ≥8 weeks along with pre- and post-treatment endoscopic evaluation. Demographic and clinical features and endoscopic and histologic assessment were recorded for comparative analysis. Histologic response was defined as <15 eos/hpf and remission as <5 eos/hpf.

The study included 68 EoE patients (20 FP and 48 OVB) with a mean age of 10.6 ± 5.2 years (range 1-20 years); 81% were boys and 68% were Caucasian. No significant demographic or clinical differences were noted between the 2 study groups. Overall histologic response to topical steroids was seen in 44 of 68 (65%) patients. A significantly greater number of patients achieved histologic response with OVB (36/48, 75%) than with FP (8/20, 40%) (P = 0.0059). Mean pretreatment peak eos/hpf was 46 ± 19 in the FP group versus 45 ± 23 in the OVB group. Mean post-treatment peak eos/hpf was 20 ± 29 in the FP group versus 12 ± 16 in the OVB group (P = 0.002). There was also a significantly greater difference in the change of absolute eos/hpf from pre- to post-treatment in the OVB group (-33) versus FP (18) (P = 0.047). A greater number of OVB-treated patients without asthma had a histologic response compared to those with asthma (P = 0.031). The response to OVB was not affected by the delivery vehicle, namely sucralose (Splenda) versus Neocate Duocal.

Our data suggest that treatment with OVB leads to better endoscopic and histologic outcomes than FP. Adherence to treatment and history of asthma are major determining factors in the response to treatments. Using Neocate Duocal as the OVB delivery vehicle is just as effective as sucralose.

Eosinophilic esophagitis (EoE) is a chronic, local, immune-mediated disorder characterized by symptoms of esophageal dysfunction and the presence of a dense eosinophilic infiltrate in the esophageal mucosa. Consensus diagnostic recommendations for EoE diagnosis included absence of histological response to a proton-pump inhibitor (PPI) trial, to exclude gastro-oesophageal reflux disease (GERD)-associated esophagitis. This recommendation exposed an entity known as "proton pump inhibitor-responsive esophageal eosinophilia" (PPI-REE), which refers to patients with EoE phenotype who are PPI-responsive and do not present GERD. In recent years, there is evidence which indicates that PPI-REE is a sub-phenotype of EoE with similar clinical, endoscopic, histological and genetic characteristics, as well as Th2-related inflammatory response. As a result, PPIs should be considered another treatment for EoE and not a diagnostic tool. PPI-REE was originally described in a case series which included two children and in two retrospective pediatric series. Later, a prospective pediatric study showed a high rate of response to PPIs at high doses with long-term maintenance at lower doses. PPI monotherapy in children with esophageal eosinophilia (EE) has been observed to reduce eotaxin-3 expression in epithelial cells and to practically reverse the allergy and inflammatory transcriptome. These data reveal that PPIs are also an effective treatment for EoE in pediatric patients, although more studies are necessary in order to define the best induction and maintenance treatment regimen, the long-term safety profile and their influence on the occurrence of fibrosis and esophageal remodeling.

Topical corticosteroids or six-food elimination diet is recommended as initial therapy for eosinophilic esophagitis (EoE).

We aimed to summarize published manuscripts that report outcomes of these therapies for EoE.

We performed a systematic review in MEDLINE, Web of Science, and Embase of published manuscripts describing topical fluticasone, topical budesonide, and six-food elimination diet as therapies for EoE. We conducted meta-analysis of symptom improvement and the change in peak mucosal eosinophil count, with heterogeneity between studies examined with meta-regression analysis.

Systematic review yielded 51 articles that met inclusion criteria. Summary histologic response rates were 68.3% [95% prediction limits (PL) 16.2-96.0%] for fluticasone, 76.8% (95% PL 36.1-95.1%) for budesonide, and 69.0% (95% PL 31.9-91.4%) for six-food elimination diet. Corresponding decreases in eosinophil counts were 37.8 (95% PL 19.0-56.7), 62.5 (95% PL 125.6 to -0.67, and 44.6 (95% PL 26.5-62.7), respectively. Symptom response rates were 82.3% (95% PL 68.1-91.1%), 87.9% (95% PL 42.7-98.6%), and 87.3% (95% PL 64.5-96.3%), respectively. Meta-regression analyses decreased the initially large estimate of residual heterogeneity and suggested differences in histologic response rate associated with study populations' baseline eosinophil count and age.

The literature describing topical corticosteroids and six-food elimination diet consists of small studies with diverse methods and population characteristics. Meta-analysis with meta-regression shows initial histologic and symptomatic response rates on the same order of magnitude for topical corticosteroids and six-food elimination diet, but heterogeneity of study designs prevents direct comparison of modalities.

To update rapidly evolving concepts regarding the controversial entity of 'proton pump inhibitor (PPI)-responsive esophageal eosinophilia,' referring to patients with clinical, endoscopic and histologic features of eosinophilic esophagitis (EoE) who achieve remission on PPI therapy.

Up to half of pediatric and adult patients with typical EoE symptoms and histology achieve clinico-pathologic remission on PPI therapy, irrespective of whether esophageal pH monitoring demonstrates abnormal acid reflux. In patients with clinical and histologic features of EoE, genotypic and phenotypic features of PPI responders and nonresponders are virtually indistinguishable, and different from those of patients with gastroesophageal reflux disease. In PPI responders, PPIs effects on esophageal Th2 inflammation and gene expression are similar to those of topical steroids in PPI nonresponders. These therapies, along with diets, recently have been shown to be potentially interchangeable in two small series.

Proton pump inhibitor-responsive esophageal eosinophilia is an inappropriate disease descriptor, arbitrarily based on a response to a single drug, and should be abandoned. Patients who have esophageal eosinophilia and esophageal symptoms that resolve with PPI therapy have phenotypic, molecular, mechanistic, and therapeutic features indistinguishable from similar patients who do not respond to PPIs. These patients with PPI responsiveness should be considered within the spectrum of EoE.

Topical corticosteroids or dietary elimination are recommended as first-line therapies for eosinophilic esophagitis, but data to directly compare these therapies are scant. We performed a cost utility comparison of topical corticosteroids and the 6-food elimination diet (SFED) in treatment of eosinophilic esophagitis, from the payer perspective.

We used a modified Markov model based on current clinical guidelines, in which transition between states depended on histologic response simulated at the individual cohort-member level. Simulation parameters were defined by systematic review and meta-analysis to determine the base-case estimates and bounds of uncertainty for sensitivity analysis. Meta-regression models included adjustment for differences in study and cohort characteristics.

In the base-case scenario, topical fluticasone was about as effective as SFED but more expensive at a 5-year time horizon ($9261.58 vs $5719.72 per person). SFED was more effective and less expensive than topical fluticasone and topical budesonide in the base-case scenario. Probabilistic sensitivity analysis revealed little uncertainty in relative treatment effectiveness. There was somewhat greater uncertainty in the relative cost of treatments; most simulations found SFED to be less expensive.

In a cost utility analysis comparing topical corticosteroids and SFED for first-line treatment of eosinophilic esophagitis, the therapies were similar in effectiveness. SFED was on average less expensive, and more cost effective in most simulations, than topical budesonide and topical fluticasone, from a payer perspective and not accounting for patient-level costs or quality of life.

Proton pump inhibitor-responsive esophageal eosinophilia (PPI-REE) is a newly recognized form of eosinophilic esophagitis (EoE) that responds to PPI therapy. It remains unclear whether PPI-REE represents a subphenotype of gastroesophageal reflux disease, a subphenotype of EoE, or its own distinct entity. The aim was to evaluate the clinicopathologic features of PPI-REE.

Six patients were diagnosed with PPI-REE based on symptoms, endoscopic abnormalities, esophageal eosinophilia with ≥15 eosinophils/high-power field, and a response to PPI treatment. Symptoms and endoscopic and pathological findings were evaluated.

The median follow-up duration was 12 months. Presenting symptoms included dysphagia, heartburn, chest pain, foreign body sensation, acid reflux, and sore throat. All patients had typical endoscopic findings of EoE such as esophageal rings, linear furrows, nodularity, and whitish plaques. Three patients had a concomitant allergic disorder, and one had reflux esophagitis. Four patients exhibited elevated serum IgE, and five had positive skin prick tests. All patients experienced symptomatic resolution within 4 weeks and histologic resolution within 8 weeks after starting PPI therapy. There was no symptomatic recurrence.

PPI therapy induced rapid resolution of symptoms and eosinophil counts in patients with PPI-REE. Large-scale studies with long-term follow-up are warranted.

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease defined by the 2nd EoE consensus panel as: 'symptoms related to esophageal dysfunction, ≥15 eosinophils per high-power field, eosinophilia that persists after a trial of proton pump inhibitor (PPI) therapy, and exclusion of other secondary causes of esophageal eosinophilia'. After Ngo et al. first reported a case series of 3 patients initially diagnosed with eosinophilic esophagitis responding endoscopically and histologically to PPI therapy, the term PPI-responsive esophageal eosinophilia has evolved. Several studies have since confirmed the existence of this entity. Although recent ACG guidelines call for a 2-month course of PPI followed by endoscopy biopsies this recommendation is classified as a strong recommendation with 'low evidence', and has not been proven in the literature. We present a case of PPI-REE treated with rabeprazole 20 mg BID for 2 months, and describe simultaneous symptom resolution with histological and endoscopic remission of disease. This unique case with serial endoscopy and histology at baseline and monthly suggests the current recommendation of at least two months therapy with PPIs dosed twice daily is appropriate. Future studies will need to address duration of high dose therapy, whether patients can be stepped down to once a day PPI, and therapeutic strategy for transient responders.

Eosinophilic esophagitis (EoE) is an emerging allergic, IgE- and non-IgE (Th2 cell)-mediated disease. There are major gaps in the understanding of the basic mechanisms that drive the persistence of EoE. We investigated whether esophageal biopsies from children with EoE demonstrate an inflammatory response that is distinct from normal controls. We prospectively enrolled 84 patients, of whom 77 were included in our analysis, aged 4-17 years (12.8±3.8 years; 81% males). Five esophageal biopsies were collected from each patient at the time of endoscopy. Intramucosal lymphocytes were isolated, phenotyped and stimulated with phorbol 12-myristate 13-acetate/ionomycin to measure their potential to produce cytokines via flow cytometry. We also performed cytokine arrays on 72-h biopsy culture supernatants. CD8(+) T cells, compared with CD4(+) T cells, synthesized more TNF-α and interferon (IFN)-γ after mitogen stimulation in the EoE-New/Active vs EoE-Remission group (P=0.0098; P=0.02) and controls (P=0.0008; P=0.03). Culture supernatants taken from explant esophageal tissue contained 13 analytes that distinguished EoE-New/Active from EoE-Remission and Controls. Principal component analysis and cluster analysis based on these analytes distinctly separated EoE-New/Active from EoE-Remission and Controls. In summary, we have identified a previously unappreciated role for CD8(+) T lymphocytes with potential to produce TNF-α and IFN-γ in EoE. Our results suggest that CD8(+) T cells have a role in the persistence or progression of EoE. We have also identified a panel of analytes produced by intact esophageal biopsies that differentiates EoE-New/Active from EoE-Remission and controls. Our results suggest that esophageal epithelial cells may have specific immune effector functions in EoE that control the type and amplitude of inflammation.