Eosinophilic esophagitis is characterized by a non-IgE-mediated food hypersensitivity

An Update on Eosinophilic Esophagitis: Etiological Factors, Coexisting Diseases, and Complications

BACKGROUND

Eosinophilic esophagitis (EoE) is an immune-mediated clinicopathological condition characterized by esophageal infiltration with eosinophils resulting in chronic inflammation and stricture.

SUMMARY

The recent increase in the incidence of EoE and the characteristic presentation of symptoms with difficulty swallowing and food bolus impaction has raised key concerns of clinicians as well as researchers. EoE often presents with dysphagia, food impaction, nausea, regurgitation or vomiting, and decreased appetite. It is more common in males, affecting both adults and children. The causative manner of this condition is complex and multifactorial. Throughout recent years, researchers have made a significant contribution to understanding the pathogenesis of EoE, genetic background, natural history, work on allergy, and standardization in the evaluation of disease activity. There is relatively high prevalence of EoE among the population, emphasizing the importance of this disease. Key messages: Esophageal involvement with eosinophils may be manifested as isolated or with coexisting conditions and should be taken into consideration in the differential diagnosis. This study aimed to provide gastroenterologists with novel insights into the evaluation of esophageal involvement with eosinophils and to pay special attention to the etiological factors, coexisting clinical diseases, and complications.

Nutritional Aspects of Pediatric Gastrointestinal Diseases

In the last decade, the role of nutritional management in pediatric gastrointestinal diseases has gained increasing popularity. Disease-specific diets have been introduced as conventional treatments by international guidelines. Patients tend to more willingly accept food-based therapies than drugs because of their relatively “harmless” nature. Apart from a diet’s therapeutic role, nutritional support is crucial in maintaining growth and improving clinical outcomes in pediatric patients. Despite the absence of classical “side effects”, however, it should be emphasized that any dietary modification might have negative consequences on children’s growth and development. Hence, expert supervision is always advised, in order to support adequate nutritional requirements. Unfortunately, the media provide an inaccurate perception of the role of diet for gastrointestinal diseases, leading to misconceptions by patients or their caregivers that tends to overestimate the beneficial role of diets and underestimate the potential adverse effects. Moreover, not only patients, but also healthcare professionals, have a number of misconceptions about the nutritional benefits of diet modification on gastrointestinal diseases. The aim of this review is to highlight the role of diet in pediatric gastrointestinal diseases, to detect misconceptions and to give a practical guide for physicians on the basis of current scientific evidence.

Impact of food challenge on local oesophageal immunophenotype in eosinophilic oesophagitis

BACKGROUND

Eosinophilic oesophagitis (EoE) is caused by the ingestion of food antigens. Dietary avoidance can result in clinical and histological remission, while food reintroduction can cause recurrence. It is uncertain if food antigen processing and immune activation occurs locally, in the oesophagus. Therefore, we performed a comparative study of the density of cell surface proteins (known to be involved with antigen presentation) on oesophageal tissue prior to, and following food antigen induced disease recurrence. A secondary aim was to consider novel biomarkers.

METHOD

Adult patients with a diagnosis of EoE, who had achieved histological remission with an elimination diet (<15 eosinophils per high power field at oesophageal biopsy), and who underwent food challenge with proven recurrence were included. Immunohistochemistry/immunofluorescence for CD1a, CD3, CD28, CD40, CD69, CD80, CD138, CXCR3 and HLA-DR was performed. Staining intensity of each biomarker (pixels/mm² ) was quantified by semi-automated analysis (Studio-FL software).

RESULTS

Fourteen cases of EoE (pre and post food challenge), 6 GORD and 5 healthy controls were included. HLA-DR, CD3, CD28, CD40 and CD 138 significantly increased with food reintroduction (P = <0.05). CD1a, CD 69, CD 80 and CXCR3 did not measurably change.

CONCLUSION

The presence of cell surface proteins typically associated with antigen presentation (following food antigen induced recurrence) suggests immune activation occurs in the oesophagus, and the relative lack of langerhans cells (CD1a) may indicate this cell type is unimportant. The cell surface protein CD 138 increases with disease recurrence, is not elevated in GORD or healthy controls, and has promise as a biomarker.

Eosinophilic esophagitis-established facts and new horizons

Despite dramatic advances in our understanding of the pathogenesis and course of disease in the relatively short timeframe since the discovery and first description of eosinophilic esophagitis (EoE) less than three decades ago, many open questions remain to be elucidated. For instance, we will need to better characterize atypical clinical presentations of EoE and other forms of esophageal inflammatory conditions with often similar clinical presentations, nut fulfilling current diagnostic criteria for EoE and to determine their significance and interrelationship with genuine EoE. In addition, the interrelationship of EoE with other immune-mediated diseases remains to be clarified. Hopefully, a closer look at the role of environmental factors and their interaction with genetic susceptibility often in context of atopic predisposition may enable identifying the candidate substances/agents/allergens and potentially earlier (childhood) events to trigger the condition. It appears plausible to assume that in the end—comparable to current concepts in other immune-mediated chronic diseases, such as for instance inflammatory bowel disease or asthma bronchiale—we will not be rewarded with the identification of a “one-and-only” underlying pathogenetic trigger factor, with causal responsibility for the disease in each and every EoE patient. Rather, the relative contribution and importance of intrinsic susceptibility, i.e., patient-driven factors (genetics, aberrant immune response) and external trigger factors, such as food (or aero-) allergens as well as early childhood events (e.g., infection and exposure to antibiotics and other drugs) may substantially differ among given individuals with EoE. Accordingly, selection and treatment duration of medical therapy, success rates and extent of required restriction in dietary treatment, and the need for mechanical treatment to address strictures and stenosis require an individualized approach, tailored to each patient. With the advances of emerging treatment options, the importance of such an individualized and patient-centered assessment will increase even further.

A Clinical Perspective on the Dietary Therapies for Pediatric Eosinophilic Esophagitis: The Gap Between Research and Daily Practice

Pediatric eosinophilic esophagitis (ped-EoE) is an immune-mediated pathology affecting 34 per 100.000 children. It is characterized by an esophageal inflammation caused by an immune response towards food antigens that come into contact with the esophageal lining. Depending on the age of the child, symptoms can vary from abdominal pain, vomiting and failure to thrive to dysphagia and food impaction. The diagnosis of this chronic disease is based on the symptoms of esophageal dysfunction combined with an infiltration of more than 15 eosinophils per high-power field and the exclusion of secondary causes. The treatment modalities include the 3Ds: Drugs, allergen avoidance by Diet and/or esophageal Dilation. In this review we focused on the efficacy of dietary approaches in ped-EoE, which currently include the elemental diet (amino acid-based diet), the empiric elimination diet and the allergy test-directed elimination diet. Although several reviews have summarized these dietary approaches, a lack of consistency between and within the elimination diets hampers its clinical use and differences in subsequent reintroduction phases present a barrier for dietary advice in daily clinical practice. We therefore conducted an analysis driven from a clinician's perspective on these dietary therapies in the management of ped-EoE, whereby we examined whether these variations within dietary approaches, yet considered to be similar, could result in significant differences in dietary counseling.

Dietary Management of Eosinophilic Esophagitis: Tailoring the Approach

Eosinophilic esophagitis (EoE) is a unique form of non-immunoglobulin E-mediated food allergy, restricted to the esophagus, characterized by esophageal eosinophil-predominant inflammation and dysfunction. The diagnosis requires an esophago-gastroduodenoscopy with esophageal biopsies demonstrating active eosinophilic inflammation with 15 or more eosinophils/high-power field, following the exclusion of alternative causes of eosinophilia. Food allergens trigger the disease, withdairy/milk, wheat/gluten, egg, soy/legumes, and seafood the most common. Therapeutic strategies comprise dietary restrictions, proton pump inhibitors, topical corticosteroids, biologic agents, and esophageal dilation when strictures are present. However, avoidance of trigger foods remains the only option targeting the cause, and not the effect, of the disease. Because EoE relapses when treatment is withdrawn, dietary therapy offers a long-term, drug-free alternative to patients who wish to remain off drugs and still be in remission. There are currently multiple dietary management strategies to choose from, each having its specific efficacy, advantages, and disadvantages that both clinicians and patients should acknowledge. In addition, dietary regimens should be tailored around each individual patient to increase the chance of tolerability and long-term adherence. In general, liquid elemental diets devoid of antigens and elimination diets restricting causative foods are valuable options. Designing diets on the basis of food allergy skin tests results is not reliable and should be avoided. This review summarizes the most recent knowledge regarding the clinical use of dietary measures in EoE. We discussed endpoints, rationale, advantages and disadvantages, and tailoring of diets, as well as currently available dietary regimens for EoE.

Classification of patients with esophageal eosinophilia by patterns of sensitization revealed by a diagnostic assay for multiple allergen-specific IgEs

BACKGROUND

Eosinophilic esophagitis (EoE) is considered to be an immunoglobulin E (IgE)-mediated allergic disorder. Our goal was to examine IgE-mediated allergic sensitization patterns in patients with esophageal eosinophilia (EE).

METHODS

We enrolled subjects with EE who underwent evaluation with a diagnostic panel to document multiple allergen-specific IgEs. Statistically significant groups were identified by cluster analysis. We also defined allergens based on their characteristics including outdoor, indoor, plant, and animal allergens.

RESULTS

We classified patients with EE into 3 distinct groups, including cluster 1 (n = 62) who were minimally sensitized to most allergens except pollen and house dust, cluster 2 (n = 30) who were hypersensitized to outdoor and plant allergens, and cluster 3 (n = 15) who were hypersensitized to most allergens, most notably to indoor and animal allergens. Dysphagia reported among those in clusters 1, 2, and 3 at 35.5%, 46.7%, and 73.3%, respectively, (p = 0.028) and EoE endoscopic reference scores (EREFS) at 3.0, 6.0, and 8.0, respectively, (p < 0.001) differed significantly between the 3 clusters. Those in cluster 3 had a significantly higher prevalence of dysphagia (35.5% vs. 73.3%, p = 0.030), and higher EREFS with respect to rings (0.3 vs. 0.9, p = 0.003) and strictures (0.0 vs. 0.13, p = 0.011) compared to those in cluster 1.

CONCLUSIONS

IgE-mediated allergic sensitization patterns are associated with clinical features of patients with EE. Use of a diagnostic panel that detects multiple allergen-specific IgEs can help to explain the heterogeneous phenotype of this patient cohort.

Conserved IFN Signature between Adult and Pediatric Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an allergic inflammatory disease of the esophagus that occurs in both children and adults. Previous studies of affected tissue from pediatric cohorts have identified prominent signatures of eosinophilia and type 2 inflammation. However, the details of the immune response in adults with EoE are still being elucidated. To determine whether EoE in adults shares inflammatory profiles with those observed in children, we performed RNA sequencing of paired human esophageal biopsies and blood samples from adults with EoE or gastroesophageal reflux disease. Unbiased analysis of differentially expressed genes in tissue revealed a strong IFN signature that was significantly enriched in EoE patients as compared with patients with gastroesophageal reflux disease. Both type I and type II IFN-responsive genes were upregulated in adult biopsies, but not in blood. A similar increase in expression of IFN gene sets was observed in pediatric EoE biopsies as compared with non-EoE samples, and in public pediatric and adult RNA-sequencing data. Finally, we found that human peripheral CD4⁺ T cells from children with EoE produce IFN-γ upon activation with EoE-causal allergens. Together, this work identifies a conserved IFN signature in pediatric and adult EoE, highlighting a role for non-type 2 inflammatory networks in the disease process in humans.

Eosinophilic esophagitis: clinical, endoscopic, histologic and therapeutic differences and similarities between children and adults

In the absence of secondary causes, eosinophilic esophagitis (EoE) is a chronic, local, progressive, T-helper type 2 immune-mediated disorder characterized by symptoms of esophageal dysfunction and eosinophil-predominant inflammation. In the last 20 years, the incidence and prevalence of EoE have risen sharply, and the chances of encountering affected patients in clinics and endoscopy rooms have increased. Nevertheless, it is estimated that the mean diagnostic delay of EoE is 4-6 years in both children and adults. Unfortunately, the longer the disease stays unrecognized, the likelier it is for the patient to have persistent or increased esophageal eosinophilic inflammation, to complain of non-resolving symptoms, and to develop fibrotic complications. Early detection depends on the recognition of initial clinical manifestations that vary from childhood to adulthood and even among patients of the same age. The disease phenotype also influences therapeutic approaches that include drugs, dietary interventions, and esophageal dilation. We have herein reviewed epidemiologic, clinical, endoscopic, and histologic features and therapeutic options of EoE focusing on differences and similarities between children and adults that may certainly serve in daily clinical practice.

Eosinophilic esophagitis: novel concepts regarding pathogenesis and clinical manifestations

Eosinophilic esophagitis is a chronic disease whose incidence and prevalence are increasing, based on a genetic-driven interaction between environment and immune system. Several gene loci involved in the development of the disease have been identified. A two-step mechanism has been hypothesized: a thymic stromal lymphopoietin-induced allergic sensitization followed by upregulation of CAPN14-related esophageal-specific pathways. Environment seems to have a larger effect than genetic variants. Factors that could play a role are allergens, drugs, colonizing bacteria and possibly Helicobacter Pylori infection. Acting on these modifiable risk factors may be a tool to prevent the disease. EoE is characterized by a typical eosinophilic infiltrate limited to the esophageal epithelium, supported by a Th2-mediated immune response, found in other atopic conditions. The key of the pathogenesis is the disfunction of the epithelial barrier which allow the interaction between allergens and inflammatory cells. Eosinophilic-predominant inflammation leads to the typical wall remodeling, histologically characterized by epithelial and smooth muscle hyperplasia, lamina propria fibrosis and neo-angiogenesis. These alterations find their clinical expression in the pattern of symptoms: dysphagia, food impaction, chest pain, heartburn.

Diet Therapy in Eosinophilic Esophagitis. Focus on a Personalized Approach

Eosinophilic esophagitis (EoE) is a chronic allergic disease defined by a marked eosinophilic inflammation and symptoms of esophageal dysfunction. EoE is a heterogeneous disease and severely impacts the quality of life of affected patients. The current therapeutic management of EoE is based on two cornerstones: medication and diet therapy, both effective but limited by several critical issues. The choice of one or the other therapy might depend on the different disease phenotypes (allergic vs. non-allergic, inflammatory vs. fibro-stenotic), patient's age (adult vs. childhood-onset), food habits, patient/family preference, and familiar financial resource. Diet therapy is a successful treatment but limited by low patient adherence, the need for several endoscopies, food restrictions, psychosocial impact, and potential nutritional deficiencies. All these limitations could be effectively overcome with multidisciplinary and personalized management. This review summarizes the most recent evidence on the dietary elimination approaches and will provide a practical guide to clinicians in managing and implementing dietary therapy for patients with EoE.

Replication and meta-analyses nominate numerous eosinophilic esophagitis risk genes

BACKGROUND

Eosinophilic esophagitis (EoE) is an emerging, chronic, rare allergic disease associated with marked eosinophil accumulation in the esophagus. Previous genome-wide association studies have provided strong evidence for 3 genome-wide susceptibility loci.

OBJECTIVE

We sought to replicate known and suggestive EoE genetic risk loci and conduct a meta-analysis of previously reported data sets.

METHODS

An EoE-Custom single-nucleotide polymophism (SNP) Chip containing 956 candidate EoE risk single-nucleotide polymorphisms was used to genotype 627 cases and 365 controls. Statistical power was enhanced by adding 1959 external controls and performing meta-analyses with 2 independent EoE genome-wide association studies.

RESULTS

Meta-analysis identified replicated association and genome-wide significance at 6 loci: 2p23 (2 independent genetic effects) and 5q22, 10p14, 11q13, and 16p13. Seven additional loci were identified at suggestive significance (P < 10-6): 1q31, 5q23, 6q15, 6q21, 8p21, 17q12, and 22q13. From these risk loci, 13 protein-coding EoE candidate risk genes were expressed in a genotype-dependent manner. EoE risk genes were expressed in disease-relevant cell types, including esophageal epithelia, fibroblasts, and immune cells, with some expressed as a function of disease activity. The genetic risk burden of EoE-associated genetic variants was markedly larger in cases relative to controls (P < 10-38); individuals with the highest decile of genetic burden had greater than 12-fold risk of EoE compared with those within the lowest decile.

CONCLUSIONS

This study extends the genetic underpinnings of EoE, highlighting 13 genes whose genotype-dependent expression expands our etiologic understanding of EoE and provides a framework for a polygenic risk score to be validated in future studies.

Food-induced immediate response of the esophagus-A newly identified syndrome in patients with eosinophilic esophagitis

BACKGROUND

Dysphagia is the main symptom of adult eosinophilic esophagitis (EoE). We describe a novel syndrome, referred to as "food-induced immediate response of the esophagus" (FIRE), observed in EoE patients.

METHODS

Food-induced immediate response of the esophagus is an unpleasant/painful sensation, unrelated to dysphagia, occurring immediately after esophageal contact with specific foods. Eosinophilic esophagitis experts were surveyed to estimate the prevalence of FIRE, characterize symptoms, and identify food triggers. We also surveyed a large group of EoE patients enrolled in the Swiss EoE Cohort Study for FIRE.

RESULTS

Response rates were 82% (47/57) for the expert and 65% (239/368) for the patient survey, respectively. Almost, 90% of EoE experts had observed the FIRE symptom complex in their patients. Forty percent of EoE patients reported experiencing FIRE, more commonly in patients who developed EoE symptoms at a younger age (mean age of 46.4 years vs 54.1 years without FIRE; P < .01) and in those with high allergic comorbidity. Food-induced immediate response of the esophagus symptoms included narrowing, burning, choking, and pressure in the esophagus appearing within 5 minutes of ingesting a provoking food that lasted less than 2 hours. Symptom severity rated a median 7 points on a visual analogue scale from 1 to 10. Fresh fruits/vegetables and wine were the most frequent triggers. Endoscopic food removal was significantly more commonly reported in male patients with vs without FIRE (44.3% vs 27.6%; P = .03).

CONCLUSIONS

Food-induced immediate response of the esophagus is a novel syndrome frequently reported in EoE patients, characterized by an intense, unpleasant/painful sensation occurring rapidly and reproducibly in 40% of surveyed EoE patients after esophageal contact with specific foods.

Nutritional approach to eosinophilic esophagitis: which diet and when

Dietary elimination therapy has been for a long time an option for patients with eosinophilic esophagitis (EoE) and remains the only therapy targeting the cause of the disease. Different dietary approaches have been described along the last 3 decades, and cumulative evidence has defined the effectiveness and usefulness of each approach. Elemental diets are highly effective to induce EoE remission, but unpractical in most patients. Allergy testing-directed food restrictions resulted inefficient to induce remission in a significant proportion of patients (especially adults) and show a low concordance with the dietary causes of EoE. Empiric elimination diets are currently considered the most effective drug-free treatment for patients of all ages with EoE, after widely providing reproducible results. Highly restrictive empiric six-food elimination diets have paved the way to most efficient and less restrictive step-up approaches, which now include four-food and two-food elimination diets. The potential role of milk-elimination, especially in children, should be also considered. Multiple factors including demographics, nutritional status, patient and family lifestyles, social and financial support, and acceptance of repeated endoscopies influence the results of dietary therapy. Dietary therapy in EoE should be patient centered, and the patients and/or their families together with the medical provider should participate in the decision to set up this treatment. This article updates recent knowledge on dietary therapy for EoE and provides guideline to choose the most suitable alternative for patients with EoE, as well as practical tips to achieve the best results in clinical practice.

Eosinophilic Esophagitis as a Side Effect of Food Oral Immunotherapy

Food allergies (FAs) include a spectrum of immune-mediated serious and potentially life-threatening medical conditions with an overall estimated prevalence ranging from 4% to 8% in the U.S. and Europe. Significant progress in food allergen-specific immunotherapy has been accomplished over the past 10 years. The most studied strategy has been oral immunotherapy (OIT), also known as food desensitization, a treatment in which a child is slowly and deliberately given a small amount of the food to ingest (that previously was a food allergy trigger) with the ultimate goal of the child eating that food without a reaction. OIT is now recommended in the European guidelines for the treatment of milk, egg, and peanut allergies and was the first American Food Drug Administration (FDA) approved product for the prevention of severe reaction to peanuts in 4–17 year olds to be released on the market. The side effects associated with OIT treatment trials are mild to moderate, predominantly oropharyngeal, and easily treated. More severe reactions, such as generalized urticaria/angioedema, wheezing/respiratory distress, laryngeal edema, and repetitive emesis, have been reported. However systemic reactions are very rare. Low-dose immunotherapy is associated with significantly fewer side effects. Currently, its most limiting allergic side effect is that approximately 10–15% of subjects treated with OIT experience gastrointestinal symptoms, preventing the continuation of therapy. Eosinophilic esophagitis (EoE) has also been reported as a cause of persistent abdominal symptoms in OIT.

Immunological Outcomes of Allergen-Specific Immunotherapy in Food Allergy

IgE-mediated food allergies are caused by adverse immunologic responses to food proteins. Allergic reactions may present locally in different tissues such as skin, gastrointestinal and respiratory tract and may result is systemic life-threatening reactions. During the last decades, the prevalence of food allergies has significantly increased throughout the world, and considerable efforts have been made to develop curative therapies. Food allergen immunotherapy is a promising therapeutic approach for food allergies that is based on the administration of increasing doses of culprit food extracts, or purified, and sometime modified food allergens. Different routes of administration for food allergen immunotherapy including oral, sublingual, epicutaneous and subcutaneous regimens are being evaluated. Although a wealth of data from clinical food allergen immunotherapy trials has been obtained, a lack of consistency in assessed clinical and immunological outcome measures presents a major hurdle for evaluating these new treatments. Coordinated efforts are needed to establish standardized outcome measures to be applied in food allergy immunotherapy studies, allowing for better harmonization of data and setting the standards for the future research. Several immunological parameters have been measured in food allergen immunotherapy, including allergen-specific immunoglobulin levels, basophil activation, cytokines, and other soluble biomarkers, T cell and B cell responses and skin prick tests. In this review we discuss different immunological parameters and assess their applicability as potential outcome measures for food allergen immunotherapy that may be included in such a standardized set of outcome measures.

Clinical and anatomopathological features of eosinophilic oesophagitis in children and adults

INTRODUCTION

Eosinophilic oesophagitis (EoE) is a chronic clinical-pathological disorder with an immunological basis characterised by symptoms of oesophageal dysfunction and, histologically, eosinophilic inflammation.

OBJECTIVE

To evaluate the clinical characteristics and differences in children and adults diagnosed with EoE in a tertiary level hospital.

METHOD

Descriptive, retrospective and cross-sectional study. We randomly selected 40 children and 40 adults diagnosed with EoE between 2009 and 2016. The patient characteristics were analysed by means of epidemiological, clinical, diagnostic and therapeutic variables.

RESULTS

The average age at diagnosis was 10 years (children) and 34 years (adults), with a higher frequency in males. The majority were sensitised to aeroallergens (77.5% children vs. 82.5% adults) and foods (75% children vs. 82.5% adults). Statistically significant differences were detected in sensitisation to fruits (p=0.007) and grains (p<0.001). Differences were observed in impaction (22.5% children vs. 82.5% adults), dysphagia (42.5% children vs. 77.5% adults) and abdominal pain (25% children vs. 7.5% adults). Endoscopy showed that children had a higher frequency of exudates (92.5%) and adults, trachealisation (50% vs. 5%) and stenosis (17.5% vs. 2.5%). Statistically significant differences were found in treatment with topical corticosteroids (30% children vs. 77.5% adults), with a variable positive response. 77.5% of the patients received elimination diets.

CONCLUSIONS

Statistically significant differences were observed between the paediatric and adult populations in the food sensitisation profiles, clinical manifestations, endoscopic findings and treatments received. This is a complex pathology that calls for a multidisciplinary team and would require new non-invasive techniques to facilitate its management.

Epidemiology and risk factors for eosinophilic esophagitis: lessons for clinicians

INTRODUCTION

The rapid expansion in the epidemiology of eosinophilic esophagitis (EoE) is being documented, along with cumulative research assessing environmental exposures associated with EoE and susceptibility due to genetic variants.

AREAS COVERED

Incidence rates for EoE of 5-10 new cases per 100,000 inhabitants annually have shown an increase in recent reports of up to 20 in some countries; the highest prevalence being reported for Europe and North America, where EoE now affects more than 1 out of 1,000 people. EoE has been shown to be associated with several disorders, Th2-mediated atopies being the most common. Patients with EoE exhibit increased frequency of asthma, allergic rhinitis and eczema, and EoE has been considered as a late component of the atopic march. Risk variants in TSLP, CAPN14 and LRCC32 genes, among others, have all been related to EoE, and interact with prenatal and early life exposure potentially modifying abundance and composition of gut microbiome. Dysregulated interactions between bacteria and mucosal immunity emerge as leading causes of EoE.

EXPERT OPINION

The expanding epidemiology of EoE, the resources needed and subsequent increasing healthcare costs require additional effort to optimize cost-effective management and unveil mechanisms that enhance the development of future preventive strategies.

Dietary therapy for eosinophilic esophagitis: chances and limitations in the clinical practice

INTRODUCTION

Eosinophilic esophagitis (EoE) is a non-Immunoglobulin E-mediated food allergy that currently represents the main cause of dysphagia and food impaction in children and young adults. Diet remains the only therapy targeting the cause of the disease. Relevant advances in recent years allow novel approaches to dietary therapy in EoE.

AREAS COVERED

An up-to-date review on dietary therapy for EoE is provided, as a potential first-line anti-inflammatory therapy able to induce and maintain remission in a significant proportion of patients. Unpractical elemental diets and suboptimal food allergy testing-directed food restrictions paved the way for empiric elimination diets, which currently are to be considered as the most effective drug-free treatment for EoE. After largely restrictive empiric six-food elimination diets, most efficient step-up approaches now include four-food and two-food elimination diets. The potential of milk-elimination is also discussed.

EXPERT COMMENTARY

An empiric elimination diet step-up strategy should be currently considered as the initial approach for dietary treatment in EoE patients of all ages. Compared to a top-down strategy, step-up diets reduce the need for endoscopic procedures, shorten diagnostic process times, and avoid unnecessary restrictions. Furthermore, early identification of responders with few food triggers may select best candidates for maintenance dietary therapy.

Food allergy and eosinophilic gastrointestinal disorders

Eosinophilic esophagitis (EoE) is a non-immunoglobulin E mediated disorder that has been seen with increasing frequency over the past 25 years. Although the presentation varies per age group from vomiting and refusal to eat in infants and toddlers to abdominal pain and dysphagia in school-aged children, and food impaction and indigestion in adolescents and adults. Treatment options include proton-pump inhibitors, dietary avoidance, swallowed steroids, or a combination of these. Newer therapies with biologics show promise in early studies. Cow's milk is the most common food trigger of EoE across all age groups, followed by wheat and eggs. Different dietary avoidance strategies have been used, and help from a knowledgeable nutritionist is often key to success. Patients with EoE commonly have other baseline atopic disease. Clinicians who take care of patients who are atopic, therefore, should have a higher index of suspicion for EoE in patients with dysphagia. The goals of treatment are both a decrease in symptoms and normalization of esophageal histology. Eosinophilic gastrointestinal diseases are less common and less likely to respond to dietary therapies and/or avoidance. Pathogenesis seems to be different and may be more autoimmune mediated. Trialing dietary restrictions is certainly an option in this cohort of patients. For persistent symptoms and abnormalities, systemic medications have been used, although biologics may be used in the future. Additional studies are needed to determine which patients will respond to which therapies.

[Recommendations for the diagnosis and practical management of paediatric eosinophilic oesophagitis]

Eosinophilic oesophagitis is an emerging and chronic disorder mediated by the immune system, and is characterised by symptoms of oesophageal dysfunction and inflammation with isolated eosinophil infiltration in the oesophagus. It is more common in males and in atopic subjects, and the symptoms vary with age. In younger children, there is vomiting, abdominal pain and dietary problems, with dysphagia and food impaction in older children and adolescents. The diagnosis is based on the presence of symptoms and oesophageal inflammation with ≥ 15 eosinophils / high power field, and after ruling out other causes of oesophageal eosinophilia. Without treatment, the disease usually persists and can progress to fibrostenotic forms more common in adults. The treatment options included proton pump inhibitors, empirical elimination diets, and swallowed topical corticosteroids. Maintenance therapy is advisable after the induction treatment. Diet is the only treatment that is directed at the cause of the disease, on identifying the triggering food or foods. The response to the treatments requires a histological assessment due to the poor agreement between the symptoms and the oesophageal inflammation. The practical management of Eosinophilic oesophagitis presents with challenges, due to, among other causes, the current lack of availability of specific drugs, and to its approach with, occasionally complex, diet treatments. The present document, prepared by the Working Group on Eosinophilic Gastrointestinal Disorders of the Spanish Society of Paediatric Gastroenterology, Hepatology and Nutrition, has as its objective to help in the diagnostic and therapeutic approach to paediatric eosinophilic oesophagitis, based on the recent evidence-based consensus guidelines.

Disodium cromoglycate treatment reduces TH2 immune response and immunohistopathological features in a murine model of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an emergent chronic disease of the esophagus. The immunopathological process in EoE is characterized by Th2 immune response and prominent eosinophilic influx, in response to common food allergens. The classical treatment consists of allergen elimination diet and systemic/topical corticosteroid therapy. Nevertheless, patients do not always comply to treatment, and the prolonged corticosteroid therapy can cause side effects, therefore, there is an immediate need for new therapeutic approach for EoE. Disodium cromoglicate (DSCG) is a substance broadly used in allergic asthma treatment, and a well-known mast cell activation stabilizer. However, its effect in EoE have not been evaluated yet. This study aimed to assess the effects of DSCG treatment in an EoE experimental model. Male Balb/C mice were subcutaneously sensitized for five days with OVA, and subsequently orally OVA-challenged, DSCG administration was performed between the OVA-challenges. DSCG treatment not only reduced eosinophilic and mast cell influx, as well as reduced fibrosis. In addition, tslp, GATA_3, IL-5, FoxP₃ and IL-10 mRNA expression were reduced in esophageal mucosa, associated with lower Th2 (CD3⁺CD4⁺GATA3⁺IL4⁺) and B cells (CD19⁺CD40⁺) number in peripheral lymphoid organs. In conclusion, the data demonstrate DSCG treatment was effective in reducing mast cell activation and Th2 immune response, important immunopathological EoE features. Therefore, the use of DSCG as an EoE treatment can be considered a promising therapeutic approach to treat this disease.

Esophageal type 2 cytokine expression heterogeneity in eosinophilic esophagitis in a multisite cohort

BACKGROUND

There is strong evidence for a role of type 2 cytokines in the pathogenesis of eosinophilic esophagitis (EoE); however, heterogeneity in type 2 gene expression has not been examined.

OBJECTIVE

We examined type 2 immunity-associated gene expression in esophageal biopsy specimens, aiming to determine the degree of cytokine heterogeneity and its potential clinical significance.

METHODS

Patients (n = 312) were recruited from 10 sites associated with the Consortium of Eosinophilic Gastrointestinal Disease Researchers. In addition to histologic and endoscopic assessment, esophageal biopsy specimens were examined for expression of 96 genes within the EoE diagnostic panel.

RESULTS

Five subgroups of patients with active EoE were identified by unsupervised clustering based on expression of IL4, IL5, IL13, C-C motif chemokine ligand 26 (CCL26), thymic stromal lymphopoietin (TSLP), Charcot-Leyden crystal (CLC), C-C motif chemokine receptor 3 (CCR3), and CPA3. These groups differed in age (P < .02) and EoE diagnostic panel score (P < 1.08E-30) but not in eosinophil levels. The group V patients had the highest expression of IL5, TSLP, and CCL26 and genes associated with tissue remodeling, such as COL8A1, actin γ-2 (ACTG2), and tetraspanin 12 (TSPAN12). IL5 and IL13 were highly expressed in group IV; however, groups IV and V differed in age (34 vs 14 years [P < .05]). Groups II and III, which exhibited intermediate expression of IL5 and CPA3, were differentiated by high TSLP and IL13 in group III.

CONCLUSION

We observed heterogeneous type 2 gene expression among patients with active EoE. Type 2 gene overexpression was not directly proportional to disease features; this was especially true for tissue remodeling events. These findings highlight a clinical opportunity for leveraging molecular endotypes to implement personalized medicine in EoE.

Pterostilbene Inhibits FcεRI Signaling through Activation of the LKB1/AMPK Pathway in Allergic Response

In this study, the role and mechanism of pterostilbene (Pts) in mast cell degranulation in vitro and in vivo were investigated. The results showed that Pts inhibited mast cell-mediated local passive allergic reactions in mice. In addition, treatment with Pts reduced both histamine release and calcium influx in rat peritoneal mast cells and RBL-2H3 cells and reduced IgE-mediated mast cell activation. Furthermore, the mechanism underlying Pts inhibition of mast cell signaling was probed via studying the effects of Pts on liver kinase B1 (LKB1), including the use of the LKB1 activator metformin and siRNA knockdown of LKB1. The data showed that Pts reduced the release of inflammatory mediators such as tumor necrosis factor-α, interleukin-6, leukotriene C4, and prostaglandin D2 in mast cells by activating the LKB1/adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway. Furthermore, Pts inhibited phosphorylation of FcεRI and FcεRI-mediated degranulation in RBL-2H3 cells. These effects were attenuated after LKB1 knockdown. Taken together, Pts could inhibit FcεRI signaling through activation of the LKB1/AMPK signaling pathway in IgE-mediated mast cell activation. Thus, Pts might be an effective therapeutic agent for mast cell-mediated allergic diseases.

Efficacy of Epicutaneous Immunotherapy in Children With Milk-Induced Eosinophilic Esophagitis

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is caused by an immune response to specific food allergens. There are no approved therapies beyond avoidance of the allergen(s) or treatment of inflammation. Epicutaneous immunotherapy (EPIT) reduces features of eosinophilic gastrointestinal disease in mice and pigs. We performed randomized, placebo-controlled study to determine the safety and efficacy of EPIT with Viaskin milk in children with milk-induced EoE.

METHODS

In a double-blind study, 20 children (4-17 years old) with milk-induced EoE were randomly assigned to groups given EPIT with Viaskin milk (n = 15) or placebo (n = 5) for 9 months during a milk-free period, followed by milk-containing diet for 2 months with EPIT. Then, subjects underwent upper endoscopy analysis, biopsies were collected, and maximum esophageal eosinophil counts were determined and was the primary endpoint. After upper endoscopy, patients were given open-label EPIT for 11 months (open-label phase). The subjects were allowed to consume milk if they had maximum values of fewer than 10 eosinophils/high-power field (eos/hpf); otherwise, they remained on a milk-free diet until the last 2 months of the open-label phase.

RESULTS

In the intent to treat population, there was no significant difference between the Viaskin milk group in mean eos/hpf (50.1 ± 43.97 eos/hpf) vs the placebo group (48.20 ± 56.98 eos/hpf). However, in the per-protocol population (7 patients given Viaskin milk and 2 patients given placebo), patients given Viaskin milk patients had a significantly lower mean eos/hpf count (25.57 ± 31.19) than patients given placebo (95.00 ± 63.64) (p = .038). At the end of the open-label phase, 9 of 19 evaluable subjects had mean values of fewer than 15 eos/hpf (47% response). The number of adverse events did not differ significantly between the Viaskin milk and placebo groups; there was 1 serious adverse event in the placebo group.

CONCLUSIONS

In a pilot study of pediatric patients with EoE given EPIT with Viaskin milk or placebo for 11 months, we found no significant difference between groups for the maximum eosinophil count at the end of the study. However, findings from a per-protocol analysis indicate that Viaskin milk can reduce eos/hpf. At study completion, 47% of patients who continued open-label Viaskin milk for an additional 11 months had mean values of fewer than 15 eos/hpf. ClinicalTrials.gov no: NCT02579876.

Eosinophilic esophagitis and other eosinophilic disorders of the gastrointestinal tract

Eosinophilic disorders of the gastrointestinal tract (EGID) are a group of diseases characterized by an eosinophilic inflammation limited to the GI tract. EoE is by far the most common EGID and is an atopic chronic/relapsing eosinophilic inflammation of the esophagus. It is now recognized as an increasingly common cause of esophageal dysfunction, fibrosis, stricture, and food impaction in children and adults. There are globally accepted guidelines for its treatment that are based on the use of proton pump inhibitors (PPI), corticosteroids, and diet. Many clinical trials have been published on the use of biologics in this disease. Non-EoE-EGID is a rare, more severe disease. No globally accepted guidelines exist for their treatment and diagnosis. Corticosteroids are at the moment the most effective treatment of those diseases.

IgG4 is Elevated in Eosinophilic Esophagitis but Not in Gastroesophageal Reflux Disease Patients

BACKGROUND

For eosinophilic esophagitis (EoE) recently an association with immunoglobulin (Ig)G4 rather than IgE has been reported. Gastroesophageal reflux disease (GERD) is the most important differential diagnosis of EoE. We compared esophageal IgG4 plasma cell infiltration and serum IgG4 levels of EoE patients (before and after budesonide therapy) with GERD patients.

METHODS

Prospectively collected serum samples of 17 EoE patients before and after 8 weeks of therapy with budesonide (1 mg BID) were analyzed for total and antigen-specific IgG4 and IgE levels. Also, immunohistochemical analysis of total and IgG4-positive plasma cells was performed on esophageal biopsies of these patients. In total, 14 GERD patients without histologic proof of eosinophilic infiltration were taken as a control group.

RESULTS

Total IgG4 serum levels in EoE patients were significantly higher than in GERD patients (121.0 vs. 71.2 mg/dL; P=0.038) and decreased under budesonide therapy (121.0 vs. 104.2 mg/dL; P=0.019). IgE levels did not differ significantly between all groups. In EoE patients also a high number of esophageal IgG4-positive plasma cells was detected and significantly reduced under therapy (29.1 vs. 0.1 IgG4-positive cells; P<0.001). In GERD patients no relevant esophageal plasma cell infiltration could be seen.

CONCLUSIONS

In EoE patients elevated systemic IgG4 serum levels compared with GERD patients can be seen and decrease under topical steroid therapy. Also, local IgG4 plasma cells expression is high in EoE, but not in GERD patients and normalize under therapy. These findings are further proof for a possible association of EoE with IgG4.

Non-IgE Mediated Food Allergy

Food allergies, defined as an immune response to food proteins, affect as many as 8% of young children and 2% of adults in western countries, and their prevalence appears to be rising like all allergic diseases. In addition to well-recognized urticaria and anaphylaxis triggered by IgE antibody- mediated immune responses, there is an increasing recognition of cell-mediated disorders, such as eosinophilic esophagitis and food protein-induced enterocolitis. Non-IgE-Mediated gastrointestinal food allergies are a heterogeneous group of food allergies in which there is an immune reaction against food but the primary pathogenesis is not a production of IgE and activation of mast cells and basophils. Those diseases tend to affect mainly the gastrointestinal tract and can present as acute (FPIES) or chronic reaction, such as Eosinophilic Esophagitis (EoE), Food Protein-Induced Allergic Proctocolitis (FPIAP). The role of food allergy in Non-EoE gastrointestinal Eosinophilic disorders (Non- EoE EGID) is poorly understood. In some diseases like EoE, T cell seems to play a major role in initiating the immunological reaction against food, however, in FPIES and FPIAP, the mechanism of sensitization is not clear. Diagnosis requires food challenges and/or endoscopies in most of the patients, as there are no validated biomarkers that can be used for monitoring or diagnosis of Non-IgE mediated food allergies. The treatment of Non-IgE food allergy is dependent on diet (FPIES, and EoE) and/or use of drugs (i.e. steroids, PPI) in EoE and Non-EoE EGID. Non-IgE mediated food allergies are being being investigated.

High-fat diet-induced obesity worsens TH2 immune response and immunopathologic characteristics in murine model of eosinophilic oesophagitis

BACKGROUND

Eosinophilic oesophagitis (EoE) is an emergent chronic immune-mediated disease of the oesophagus, which affects both children and adults. It is clinically characterized by dysphagia, food impaction and oesophageal eosinophilia. Epidemiological studies indicate that obesity can worsen allergic symptoms; however, its effect on EoE immunopathological response has not been evaluated yet. This study aimed to assess the effect of obesity on allergic inflammation and T helper-2 profile in an EoE experimental model.

METHODS

Obesity was induced by high-fat feeding. After 7 weeks of diet, male BALB/c mice were subcutaneously sensitized and orally challenged with OVA.

RESULTS

Obesity itself induced a significant mast cell and eosinophil accumulation in the oesophagus, trachea, gut and lung. After allergy induction, this number was higher, when compared to lean-allergic mice. Moreover, obese-allergic mice showed higher remodelling area, in the oesophagus, associated with higher IL-5 and TSLP mRNA expression. In contrast, FoxP3 and IL-10 were less expressed in comparison with lean-allergic mice. In addition, the amount of CD11c⁺ MHCII⁺ PDL1⁺ dendritic cells was reduced, while the number of CD11c⁺ MHCII⁺ CD80⁺ DCs and CD3⁺ CD4⁺ GATA₃ ⁺ IL-4⁺ cells was increased in obese-allergic mice in the spleen and lymph nodes when compared to lean-allergic mice.

CONCLUSION

Obesity aggravated the immune histopathological characteristics in the EoE experimental model, which was associated with the reduction in the regulatory profile, and the increased inflammatory cells influx, related to the T_H 2 profile. Altogether, the data provide new knowledge about obesity as a risk factor, worsening EoE symptoms, and contribute for future treatment strategies for this specific profile.

Phenotypes and endotypes in eosinophilic esophagitis

OBJECTIVE

To improve understanding of the heterogeneous presentation of eosinophilic esophagitis (EoE), and its different potential phenotypes and endotypes.

DATA SOURCES

We reviewed studies addressing EoE genetics, risks, natural history, treatment, phenotype, or endotype to assess data relating to differences in the presentation of EoE in children and adults. This review was restricted to articles in the English language.

STUDY SELECTIONS

Data source abstracts, pertinent articles, and book chapters meeting the objectives were critically reviewed.

RESULTS

Data to support differing phenotypes and endotypes in EoE are emerging, but findings are based on multiple studies and therefore sometimes incomparable. Like other atopic disorders EoE is a complex disease with diverse clinical presentations (phenotypes) based on response to therapy, natural history, and association with atopic comorbidities. Different pathogenetic mechanisms (endotypes) may drive the multiple phenotypes. T Helper type 2 inflammation, epithelial barrier defects, enhanced fibrosis, and association with rare monogenetic diseases are the most described endotypes in EoE.

CONCLUSION

Eosinophilic esophagitis is an atopic disorder that is increasing in prevalence and can be difficult to treat. Better understanding of phenotypes and endotypes in EoE may enable future care to be individualized more effectively, resulting in shorter time to remission and fewer endoscopies.

The Efficacy and Safety of Epicutaneous Immunotherapy for Allergic Diseases: A Systematic Review and Meta-Analysis

OBJECTIVES

To systematically review the effect and safety of epicutaneous immunotherapy (EPIT) for allergic diseases.

METHODS

We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, CQ VIP Database, Wanfang Data, and international trial register from their inception to July 29, 2019, without language restrictions, for randomized controlled trials (RCTs) that compared EPIT versus no EPIT for allergen-triggered allergic reactions. We assessed certainty of evidence by the GRADE approach.

RESULTS

Ten RCTs with 1,085 participants (aged from 10 months to 65 years) comparing EPIT with placebo for peanut, cow milk, or grass-pollen allergy met the eligibility criteria. A substantial benefit in terms of desensitization in EPIT group was more likely for peanut or cow milk protein allergy (risk ratio [RR] 2.34, 95% CI 1.69-3.23; I2 = 0%; high certainty evidence). EPIT increased local-treatment-related adverse events (L-TRAE; RR 1.56, 95% CI 1.03-2.36; I2 = 82%; moderate certainty evidence). But there were no significantly increased risk of any TRAEs (low certainty evidence) or systemic-TRAEs (S-TRAEs; very low certainty evidence) in EPIT group. The incidence rate of serious AEs, the use of rescue medications, and anaphylactic reactions stratified by organ systems including skin and mucosa, eyes and upper respiratory, lower respiratory, and gastrointestinal system in EPIT group were similar to placebo group. In subgroup analysis, desensitization of EPIT was significantly effective in peanut allergy (RR 2.29, 95% CI 1.64-3.21; I2 = 0%) and children <12 years (RR 2.85, 95% CI 1.92-4.24; I2 = 0%) with high certainty evidence. Only epicutaneous grass-pollen immunotherapy significantly increased the risk of S-TRAE (RR 4.65, 95% CI 1.10-19.64; I2 = 0%).

CONCLUSION

The systematic review suggests that EPIT might induce desensitization in peanut allergy and an increased risk of local AEs. These findings should be interpreted with caution owing to the limited study and heterogeneity. More data in the older (children ≥12 years and adults) and other allergic diseases are needed.

The use of amino acid-based nutritional feeds is effective in the dietary management of pediatric eosinophilic oesophagitis

INTRODUCTION

Eosinophilic oesophagitis (EoE) is an immune-mediated, chronic disease characterized by eosinophilic inflammation and esophageal dysfunction. Specific food allergens including cow's milk protein, are partially causative to disease progression, and dietary management forms three main options; the elemental diet (ED), the empirical elimination diet (EED), and the targeted elimination diet (TED). The dietary choice should be individualized, however, the European Society for Pediatric Gastroenterology, Hepatology and Nutrition guidelines recommend an ED for pediatric EoE with multiple food allergies, failure to thrive, unresponsive disease or unable to follow a highly restricted diet. The aim of this narrative review was to explore the effectiveness of the ED (using amino acid formula [AAF]), in the management of pediatric EoE.

METHODS

Literature searches were performed to identify eligible studies that described outcomes including eosinophil count, clinical symptoms, growth, and medications.

RESULTS

Overall, 10 eligible studies were found, with n = 462 patients assigned to receive AAF from a total of n = 748 (average age 6.7 years), for a duration of 4 to 8 weeks. The use of AAF reduced eosinophil levels and demonstrated remission (defined as ≤10 eosinophils per high power field) in 75%-100% of children with improvements, if not resolution, in clinical symptoms. AAF was more clinically effective than the use of the EED or TED, where remission rates were 75%-81% and 40%-69%, respectively. Few studies collected growth outcomes, however where documented these were positive for those on AAF. The long-term impacts of each diet were not thoroughly explored.

CONCLUSIONS

The use of AAF is a clinically effective management option for pediatric EoE, and further research is required to guide long-term management.

Future therapies for eosinophilic gastrointestinal disorders

OBJECTIVE

To review novel therapeutics in development for treatment of eosinophilic gastrointestinal disorders (EGIDs).

DATA SOURCES

Clinical trial data (clinicaltrials.gov) and literature search on PubMed.

STUDY SELECTIONS

Studies on treatment and clinical trials in EGIDs were included in this review.

RESULTS

During the past decade, significant progress has been made in understanding disease mechanisms in EGIDs. As a result, a variety of novel therapeutics have been developed for treatment of these disorders. Several monoclonal antibodies against targets, including interleukin (IL) 4, IL-5, IL-13, integrins, and siglec-8, have shown promise in early trials. Novel formulations of corticosteroids are also in development.

CONCLUSION

The field of EGID research has advanced rapidly, and disease-modifying therapeutics are closer to clinical application.

Allergies and Eosinophilic Esophagitis-Current Updates for the Pediatric Gastroenterologist

PURPOSE OF REVIEW

The purpose of this article is to review recent developments demonstrating the role of allergies, the utility of allergy testing, and the role of the allergist in eosinophilic esophagitis (EoE) management.

RECENT FINDINGS

The majority of patients with EoE have concurrent atopic disorders including food anaphylaxis, asthma, allergic rhinitis, and eczema. An atopic population likely is at greater risk for EoE. Delayed type hypersensitivity to food antigens is the most common pathogenic mechanism. Aeroallergens and pollen-food cross-reactivity also can trigger EoE. Th2 cell-mediated adaptive and innate immunity in response to epithelial damage occurs via IL-13- and IL-4-producing T cells and innate lymphoid cells. While IgE testing for foods is insufficient to build an elimination diet, IgE-mediated allergy may play a role in EoE severity and clinical course. There is strong evidence that Th2 immunity drives EoE. Optimal EoE management should include elucidating and managing EoE triggers and concurrent atopic diatheses.

Increased number of regulatory T cells in esophageal tissue of patients with eosinophilic esophagitis in comparison to gastro esophageal reflux disease and control groups

BACKGROUND

Eosinophilic esophagitis (EoE) is a primarily polygenic allergic disorder. Although most patients have IgE sensitization, it seems that non-IgE mediated responses mainly contribute to the pathogenesis of EoE. Regulatory T cells (Tregs) may have an important role in allergies. There are limited data on the association of Tregs and EoE. In this study, we enumerated and compared T lymphocytes and Tregs in esophageal tissue of patients with EoE, gastroesophageal reflux disease (GERD) and normal controls.

METHODS

Ten patients with EoE, ten patients with GERD and eight normal controls were included. Immunohistochemistry staining was used to enumerate T lymphocytes and Tregs. CD3+ cells were considered as T cells and FOXP3+, CD3+ cells were considered as Tregs. T cells and Tregs were counted in 10 high power fields (HPF) (×400) for each patient and the average of 10 HPFs was recorded.

RESULTS

The mean±SEM of Tregs in esophageal tissue of patients with EoE (10.90±2.14cells/HPF) was significantly higher than the GERD (2.77±0.66cells/HPF) and control groups (0.37±0.08cells/HPF) (P<0.001). Additionally, the mean±SEM of T lymphocytes in esophageal tissue of patients with EoE (24.39±3.86cells/HPF) were increased in comparison to the GERD (10.07±2.65cells/HPF) and control groups (3.17±0.93cells/HPF) (P<0.001).

CONCLUSION

There is an increase in the number of esophageal T lymphocytes and regulatory T cells in patients with EoE compared to the GERD and control groups.

Eosinophilic esophagitis: Current concepts in diagnosis and treatment

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.

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.

Allergic Comorbidity in Eosinophilic Esophagitis: Mechanistic Relevance and Clinical Implications

Allergic eosinophilic esophagitis (EoE) is a chronic, allergen-mediated inflammatory disease of the esophagus, and the most common cause of prolonged dysphagia in children and young adults in the developed world. While initially undistinguished from gastroesophageal reflux disease-associated esophageal eosinophilia, EoE is now recognized as a clinically distinct entity that shares fundamental inflammatory features of other allergic conditions and is similarly increasing in incidence and prevalence. The clinical and epidemiologic associations between EoE and other allergic manifestations are well established. In addition to exaggerated rates of atopic dermatitis, IgE-mediated food allergy, asthma, and allergic rhinitis in EoE patients, each of these allergic manifestations imparts individual and cumulative risk for subsequent EoE diagnosis. As such, EoE may be a member of the "allergic march"-the natural history of allergic manifestations during childhood. Several determinants likely contribute to the relationship between these conditions, including shared genetic, environmental, and immunologic factors. Herein, we present a comprehensive review of allergic comorbidity in EoE. We discuss areas of the genome associated with both EoE and other allergic diseases, including the well-studied variants encoding thymic stromal lymphopoietin and calpain 14, among other "atopic" regions. We summarize ways that environmental factors (such as microbiome-altering pressures and aeroallergen exposure) may predispose to multiple allergic conditions including EoE. Finally, we touch on some fundamental features of type 2 inflammation, and the resulting implications for the development of multiple allergic manifestations. We conclude with an analysis of the "type 2" biologics, and how mechanistic similarities between EoE and the other allergic manifestations have important implications for screening and treatment of the allergic patient.

Avoidant/Restrictive Food Intake Disorder in Diet-treated Children With Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an inflammatory condition of the esophagus with rising incidence in children. Owed to potential adverse effects and high costs of EoE medications, strict elimination diets are often employed as a mainstay of long-term EoE therapy in children. Currently, there are no effective tests to pinpoint food protein triggers in children with EoE. Therefore, EoE elimination diets are often broad (including milk, soy, wheat, egg, fish/shellfish, and nuts) and can greatly alter a child's baseline eating habits. Herein, we describe 2 cases of avoidant/restrictive food intake disorder (ARFID) in children with remitted EoE maintained on an elimination diet. We also present comorbidity data on ARFID and diet-treated EoE from our pediatric EoE clinic. This is the first report of disordered eating associated with EoE therapy. As EoE is becoming more common, close monitoring of intake and growth in patients treated with elimination diets will be key.

Illuminating Elimination Diets: Controversies Regarding Dietary Treatment of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an immune-mediated disease triggered by food antigens for which dietary elimination treatment can induce and sustain histologic remission. Our review aims to describe the state of the art regarding dietary treatment of EoE, highlighting a number of areas of controversy related to dietary therapy in EoE, including novel modalities for determining food triggers, making the empiric dietary elimination process more efficient, issues of cross-contamination and "dosing" of how much food to avoid or add back, costs and effects on quality of life, long-term efficacy, and the risk of developing immediate IgE-type reactions after initial dietary elimination. Elemental formulas, empiric elimination diets, and targeted allergy test-directed elimination diets are well-described treatments for EoE. Although elemental diets are most efficacious, their clinical use is limited by cost and the palatability of an exclusively liquid diet. While empiric elimination is less effective than elemental formula-based diets, they are more easily implemented and often sustainable. Since the comparative effectiveness of elimination diets with proton-pump inhibitors and swallowed topical steroids remains unknown, there are multiple areas to address with future research.

Correction to: Eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an atopic condition of the esophagus that has become increasingly recognized over the last 15 years. Diagnosis of the disorder is dependent on the patient’s clinical manifestations, and must be confirmed by histologic findings on esophageal mucosal biopsies. Patients with EoE should be referred to an allergist for optimal management, which may include dietary modifications and pharmacologic agents such as proton pump inhibitors (PPI) and corticosteroids, and for the diagnosis and management of comorbid atopic conditions. Mechanical dilation of the esophagus may also be necessary. The epidemiology, pathophysiology, diagnosis, treatment, and prognosis of EoE are discussed in this review.