Food allergy testing in eosinophilic esophagitis: what the gastroenterologist needs to know

The evolving landscape of immunotherapy for the treatment of allergic conditions

Allergic conditions, such as asthma, chronic urticaria, atopic dermatitis (AD), and eosinophilic esophagitis, have long been treated with oral and topical steroids which resulted in negative off-target effects. However, newer biologic medications are increasingly being developed and approved for treatment of these conditions. These medications have a variety of mechanisms of action to target pathophysiology specific to these diseases. As biologics become more targeted, fewer off-target effects are seen improving tolerability for patients as well as expanded options for treatment of these conditions. This review discusses monoclonal antibody therapies (omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab, tezepelumab, and tralokinumab) including their safety and use in asthma, chronic urticaria, AD, and eosinophilic esophagitis.

First Therapeutic Approval for Eosinophilic Esophagitis

Eosinophilic esophagitis (EE) is a chronic, immune-mediated or antigen-mediated esophageal disease. Treatment for patients with EE can be challenging with no previously approved medications. Current management strategies follow the four D’s paradigm of drugs, dietary elimination, dilation, and disease anxiety and hypervigilance therapy. On 20 May 2022, dupilumab was approved by FDA for EE. A dose of 300 mg dupilumab weekly significantly improved signs and symptoms of EE compared to placebo in a phase 3 trial. The approval of dupilumab will fulfill an unmet need for the increasing number of patients with EE.

Association of celiac disease with eosophageal eosinophilia and eosinophilic eosophagitis

BACKGROUND

Aim of the study was to evaluate the association between celiac disease and eosinophilic oesophagitis/oesophageal eosinophilia in children.

METHODS

A total of 278 patients with celiac disease (mean age: 7.12 ± 4.64 years, M/F: 0.77) were involved in the study. The patients were evaluated retrospectively in terms of clinical, endoscopic and histopathological findings. The association between celiac disease and eosinophilic oesophagitis/oesophageal eosinophilia was determined.

RESULTS

According to Marsh classification system 6 (2.1%) of the patients were graded type 3A, 10 (3.5%) were type 3B, 262 (94.4%) were type 3C. The histopathological examination of oesophageal biopsy specimens of the patients revealed <15 eosinophils per high power field in only 4 (1.4%) patients. Two of these patients were positive for HLA DQ8, one was DQ2, and the other one was both DQ8 and DQ2. Tissue transglutaminase IgA level was above 300 U/mL in these patients. None of them had elevated serum total IgE levels, peripheral eosinophilia and history of atopic diseases. The gastrointestinal symptoms resolved and tissue transglutaminase IgA level of the patients were declined after 3 months of gluten-free diet.

CONCLUSION

Although an association between celiac disease and eosinophilic oesophagitis/oesophageal eosinophilia have been postulated in recent years, no exact relationship was established in this study. This is the first study reporting the performance of follow-up GI endoscopy with biopsies revealing the resolution of oesophageal eosinophilia.

Eosinophilic esophagitis: an interdisciplinary clinical problem

Eosinophilic esophagitis is a newly described entity of increasing incidence. Previously thought to be a variation of gastroesophageal reflux disease, now it becomes well known among gastroenterologists, allergologists, paediatricians and pathologists. Aetiology of the disease is strongly correlated with atopic and allergic disorders but exact pathogenesis and cellular mechanisms of inflammatory process in the esophagus are still unknown. Diagnostic criteria have been described but diagnostic tools are still in the research and improvement phase. Clinical manifestation varies considerably between age groups, which causes a delay in the course of diagnosis due to improperly recognized symptoms. Since eosinophilic esophagitis is a chronic disease without a tendency to be self-limiting, delayed diagnosis may lead to complications associated with oesophageal tissue remodelling. Some forms of treatment are approved and of great therapeutical value, nevertheless clinical trials of new medications provide new possibilities. Therefore, many questions regarding eosinophilic esophagitis arise and are still unanswered.

Food-specific antibodies in oesophageal secretions: association with trigger foods in eosinophilic oesophagitis

BACKGROUND

Food antigens are clearly implicated in the induction and persistence of eosinophilic oesophagitis. Dietary elimination to identify triggers is tedious and expensive. Alternatives that can mitigate cost and improve patient quality of life during this process are needed.

AIMS

To test the hypothesis that antibodies against foods that trigger eosinophilic oesophagitis are secreted into the oesophageal lumen where they can be collected by oesophageal brushings.

METHODS

We evaluated food-specific immune responses within brushings in 68 patients undergoing endoscopy (12 controls, 13 resolved eosinophilic oesophagitis and 43 active eosinophilic oesophagitis). Seventeen participants identified their trigger foods via food elimination diets. Immunoglobulin A and immunoglobulin G4 antibodies against the four most common eosinophilic oesophagitis food triggers were measured using the ImmunoCAP assay in the oesophageal brushings. Food-specific antibody values were compared between active eosinophilic oesophagitis, resolved eosinophilic oesophagitis and controls.

RESULTS

Patients with active eosinophilic oesophagitis (>15 eosinophils/hpf) demonstrated increased immunoglobulin A and immunoglobulin G4 levels to common eosinophilic oesophagitis triggers compared to controls (327 ± 380 vs 150 ± 130 for immunoglobulin A, and 1534 ± 3346 vs 178 ± 123 for immunoglobulin G4, P < 0.003). Specific trigger foods were associated with elevated immunoglobulin A and immunoglobulin G4 responses compared to foods that did not trigger oesophageal eosinophilia (733 ± 469 vs 142 ± 64, P < 0.001 immunoglobulin A and 2620 ± 3228 vs 526 ± 1050, P < 0.001 immunoglobulin G4).

CONCLUSIONS

Food-specific antibodies are easily collected along the oesophageal lumen of eosinophilic oesophagitis patients. Further studies are needed to validate our preliminary findings to determine whether these antibodies can be used to guide elimination diet therapy.

Efficacy of Dairy Free Diet and 6-Food Elimination Diet as Initial Therapy for Pediatric Eosinophilic Esophagitis: A Retrospective Single-Center Study

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Diagnosis and treatment of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an eosinophil-rich, TH2 antigen-mediated disease of increasing pediatric and adult worldwide prevalence. Diagnosis requires greater than or equal to 15 eosinophils per high-power field on light microscopy. Symptoms reflect esophageal dysfunction, and typical endoscopic features include linear furrows, white plaques, and concentric rings. Progressive disease leads to pathologic tissue remodeling, with ensuing esophageal rigidity and loss of luminal diameter caused by strictures. Therapies include proton pump inhibitors, elimination diets, and topical corticosteroids. Effective treatment can reverse tissue fibrosis in some patients, as well as decrease the rate of food impactions. Esophageal dilation might be required to increase luminal patency. The chronic nature of EoE necessitates long-term therapy to avoid disease recurrence and complications. This review serves the function of providing the current state-of-the-art diagnostic criteria and disease management for adult and pediatric EoE.

Advancing patient care through the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR)

Recent advances in rare disease research are accelerated by the work of consortia that have been supported by the National Institutes of Health. Development of such consortia rely on multidisciplinary relationships and engagement with patient advocacy groups, as well as the National Institutes of Health and industry and academic partners. In this rostrum we present the development of such a process that focuses on eosinophilic gastrointestinal diseases. Principal investigators, patient advocacy groups, research assistants, and trainees work together to perform natural history studies that promote clinical trial readiness tools, conduct clinical trials, train a new generation of investigators, and perform innovative pilot studies.

The Microbiome and Food Allergy

The gut-associated lymphoid tissue (GALT) faces a considerable challenge. It encounters antigens derived from an estimated 1014 commensal microbes and greater than 30 kg of food proteins yearly. It must distinguish these harmless antigens from potential pathogens and mount the appropriate host immune response. Local and systemic hyporesponsiveness to dietary antigens, classically referred to as oral tolerance, comprises a distinct complement of adaptive cellular and humoral immune responses. It is increasingly evident that a functional epithelial barrier engaged in intimate interplay with innate immune cells and the resident microbiota is critical to establishing and maintaining oral tolerance. Moreover, innate immune cells serve as a bridge between the microbiota, epithelium, and the adaptive immune system, parlaying tonic microbial stimulation into signals critical for mucosal homeostasis. Dysregulation of gut homeostasis and the subsequent disruption of tolerance therefore have clinically significant consequences for the development of food allergy.

Cost-effective care in eosinophilic esophagitis

OBJECTIVE

To examine costs related to eosinophilic esophagitis (EoE), understand the source of these costs, discuss a possible approach for cost-effective care in EoE, and identify areas for future research in this topic.

DATA SOURCES/STUDY SELECTIONS

Narrative review of the literature from 1977 (first description of EoE) to March 2019, focusing on costs and cost-effectiveness analyses in EoE.

RESULTS

High costs in EoE can be related to diagnostic delays, requirement for upper endoscopy with biopsy for diagnosis and monitoring of disease activity, expensive medications currently used off-label, increased food costs related to dietary elimination treatment, frequent doctor visits with subspecialists, and complications or disease exacerbations. Provision of cost-effective care in EoE is an understudied area, and a patient-centric approach is key. There are multiple areas in which future research can make an impact. These include determining predictors of treatment response, minimally or noninvasive methods to monitor disease activity, and validation of the use of multidisciplinary care.

CONCLUSION

Eosinophilic esophagitis (EoE) is considered to be a rare disease, but the costs of care and burden of disease attributed to EoE are substantial. However, few studies examine either the costs related to EoE or the approach to cost-effective care for the EoE patient. To provide cost-effective care, a patient-centric approach and shared decision-making model are optimal. In addition, a rational strategy for EoE diagnosis and initial treatment, effective maintenance therapy for disease control and ideally to prevent complications, and appropriate long-term monitoring are all required.

Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic disorder characterized by symptoms of esophageal dysfunction and esophageal inflammation with intraepithelial eosinophils. EoE represents an important cause of upper gastrointestinal morbidity. Primary care providers are pivotal for timely and accurate recognition of symptoms of eosinophilic esophagitis, for facilitating diagnoses through specialist referrals, and for understanding management strategies. This process begins with a thorough understanding of the clinical features of EoE, its associated atopic conditions, and its evolving epidemiology.

Analysis of eosinophilic esophagitis in children with repaired congenital esophageal atresia

BACKGROUND

A high prevalence of eosinophilic esophagitis (EoE) has been preliminarily reported in patients after repair of esophageal atresia (EA), but the basis of this association is unknown.

OBJECTIVES

We aimed to (1) characterize the EoE transcriptome in patients with EA, (2) compare the EoE transcriptome in patients with EoE and EA with that in patients with EoE alone, and (3) identify transcripts that could predispose patients with EA to EoE.

METHODS

This single-center, population-based, retrospective study identified 4 EoE study cohorts: healthy control subjects, patients with EA and EoE (EA+EoE+), patients with EA without EoE (EA+EoE-), and patients with EoE without EA (EA-EoE+). Molecular signatures were assessed by using the EoE diagnostic panel, a 94-gene expression quantitative PCR array.

RESULTS

In a cohort of 110 pediatric patients with surgically repaired EA, 20 (18%) patients were given a diagnosis of EoE, representing a 364-fold enrichment of EoE in patients with EA compared with the general pediatric population. EoE diagnostic panel analyses revealed a major overlap between the EA+EoE+ and EA-EoE+ cohorts. A proportion (approximately 25%) of EoE signature genes were dysregulated in patients with EA+EoE- compared with healthy control subjects, including those involved in epithelial barrier function and type 2-associated inflammatory responses. Patients with EA+EoE+ exhibit a more severe EoE clinical phenotype than those with EA-EoE+ in terms of dysphagia and dilation need.

CONCLUSIONS

Patients with EA have increased risk of EoE. Patients with EoE with EA have a similar molecular profile compared with that of patients with EoE without EA. Dysregulated baseline epithelial barrier and type 2-associated genes in EA monomorbidity might explain the higher EoE prevalence in patients with EA.

Eosinophilic Esophagitis and the Eosinophilic Gastrointestinal Diseases: Approach to Diagnosis and Management

The eosinophilic gastrointestinal diseases (EGIDs) represent disorders of the gastrointestinal (GI) tract that result from the local infiltration and aberrant activity of eosinophils and other immune cells. Eosinophilic esophagitis (EoE) is the most well-characterized EGID and is defined by the presence of intraepithelial eosinophils in the esophagus (≥15 eosinophils per high-powered field) and clinical symptoms associated with esophageal dysfunction. The other EGIDs are rare and lack strong data regarding pathogenesis and management. The incidence and prevalence of EoE are increasing, and EoE is now a major cause of upper GI morbidity. Management is multidisciplinary, with collaboration between gastroenterologists, allergists, pathologists, and dieticians, and is aimed at amelioration of symptoms and prevention of long-term complications such as esophageal stricture. Treatment options for EoE include proton pump inhibitors, swallowed topical corticosteroids, and elimination diets. Esophageal dilation is used when esophageal strictures or fibrostenotic changes are present. Additional therapies targeting eosinophils and other mediators of Th2 inflammation are under development and are promising. Treatment options for other EGIDs typically involve corticosteroids or dietary elimination.

The Role of Allergy Testing in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is defined as a chronic, immune/antigen-mediated esophageal disease that can lead to symptoms of esophageal dysfunction. This disease is seen in both children and adults. Approximately 70% of patients with EoE have food antigen sensitization or other atopic conditions, suggesting an allergic etiology in the pathogenesis of the disease. The role of allergy testing to identify foods that lead to EoE is unclear. Three types of allergy tests currently exist: skin prick testing, atopy patch testing, and immunoassays for serum food-specific immunoglobulin E. It is important for gastroenterologists to work in conjunction with allergist colleagues in the care of patients with EoE, particularly in the management of comorbid atopic conditions.

Pathophysiology of Eosinophilic Esophagitis

Eosinophilic esophagitis is an emerging disease that is distinguished from gastroesophageal reflux disease by the expression of a unique esophageal transcriptome and the interplay of early life environmental factors with distinct genetic susceptibility elements at 5q22 (TSLP) and 2p23 (CAPN14). Rare genetic syndromes have uncovered the contribution of barrier disruption, mediated in part by defective desmosomes and dysregulated transforming growth factor beta production and signaling, to eosinophilic esophagitis pathophysiology. Experimental modeling has defined a cooperative role of activated eosinophils, mast cells, and the cytokines IL-5 and IL-13, mediated by allergic sensitization to multiple foods. Understanding these processes is opening the way to better treatment based on disrupting allergic inflammatory and type 2 cytokine-mediated responses, including anti-cytokine therapeutics and dietary therapy.

Genetic variations in the TLR3 locus are associated with eosinophilic esophagitis

Background

Eosinophilic esophagitis (EoE) is an antigen-driven disease mediated by an abnormal immune Th2 response.

Objective

The objective of this article is to investigate genes associated with regulating immune responses leading to disease susceptibility.

Methods

Twenty-seven tag single nucleotide polymorphisms (tSNPs) selected in five candidate genes (TLR3, TLR4, FOXP3, FLG and TSLP) were genotyped in 218 EoE patients and 376 controls. Skin prick tests were carried out in EoE patients with a panel of 17 aeroallergens and 22 plant- and animal-derived foods.

Results

Five tSNPs located in the TSLP locus and one tSNP located in the TLR3 locus were significantly associated with EoE. The interactions between TLR3 and TSLP loci were analyzed. TLR3+/TSLP- and TLR3-/TSLP+ individuals showed a significantly reduced susceptibility to EoE compared to TLR3-/TSLP- individuals (OR = 0.66, p = 0.036 and OR = 0.23, p = 0.00014, respectively). Likewise, TLR3+/TSLP+ individuals showed the most decreased susceptibility of developing EoE (OR = 0.16, p = 0.0001). However, the interaction gain attributed to the combination of both genes was negative (IG = -4.52%), which indicated redundancy or independent effect. Additionally, TLR3 locus was found to be associated with aeroallergen and food sensitization in EoE patients (OR = 9.67, p_c = 0.025 and OR = 0.53, p_c = 0.048, respectively).

Conclusion

TLR3 constitutes a novel genetic susceptibility locus for developing EoE, and the effects would be independent of TSLP.

Disease activity in eosinophilic esophagitis is associated with impaired esophageal barrier integrity

In eosinophilic esophagitis (EoE), the esophageal barrier integrity is impaired. Integrity can be assessed with different techniques. To assess the correlations between esophageal eosinophilia and various measures of mucosal integrity and to evaluate whether endoscopic impedance measurements can predict disease activity, endoscopies and mucosal integrity measurements were performed in adult EoE patients with active disease (≥15 eosinophils/high-power field) at baseline (n = 32) and after fluticasone (n = 15) and elemental dietary treatment (n = 14) and in controls (n = 19). Mucosal integrity was evaluated during endoscopy using electrical tissue spectroscopy (ETIS) measuring mucosal impedance and transepithelial electrical resistance (TER) and transepithelial molecule-flux through biopsy specimens in Ussing chambers. We included 61 measurements; 32 of patients at baseline and 29 after treatment, 3 patients dropped out. After treatment, 20 patients were in remission (≤15 eosinophils/high-power field) and these measurements were compared with 41 measurements of patients with active disease (at baseline or after failed treatment). All four mucosal integrity measures showed significant impairment in active EoE compared with remission. Eosinophilia was negatively correlated with ETIS and TER and positively with transepithelial molecule flux (P ≤ 0.001). The optimal ETIS cutoff to predict disease activity was 6,000 Ω·m with a sensitivity of 79% [95% confidence interval (CI) 54-94%], specificity of 84% (95% CI 69-94%), positive predictive values of 89% (95% CI 77-95%) and negative predictive values of 71% (95% CI 54-84%). In EoE patients, markers of mucosal integrity correlate with esophageal eosinophilia. Additionally, endoscopic mucosal impedance measurements can predict disease activity.NEW & NOTEWORTHY In adult patients with eosinophilic esophagitis (EoE), the mucosal integrity, measured by making use of four different parameters, correlates strongly with esophageal eosinophilia. The accuracy of endoscopically measured mucosal impedance to distinguish active disease from remission was acceptable with moderate specificity and sensitivity. Mucosal impedance measurements can predict disease activity in adult EoE patients.

Management of refractory eosinophilic oesophagitis

The goal of this Review is to discuss the clinical approach to patients who do not respond to treatment for eosinophilic oesophagitis (EoE). Refractory EoE is challenging to manage as there are limited data to guide decision-making. In this Review, refractory EoE is defined as persistent eosinophilia in the setting of incomplete resolution of the primary presenting symptoms and incomplete resolution of endoscopic findings following a PPI trial, and after treatment with either topical steroids or dietary elimination. However, this definition is controversial. This Review will examine these controversies, explore how frequently non-response is observed, and highlight potential explanations and predictors of non-response. Non-response is common and affects a large proportion of patients with EoE. It is important to systematically assess multiple possible causes of non-response, as well as consider treatment complications and an incorrect diagnosis of EoE. If non-response is confirmed, second-line treatments are required. Although the overall response rate for second-line therapy is disappointing, with only half of patients eventually responding, there are several promising agents that are currently under investigation, and the future is bright for new treatment modalities for refractory EoE.

Esophageal and Small Intestinal Mucosal Integrity in Eosinophilic Esophagitis and Response to an Elemental Diet

OBJECTIVES

The esophageal mucosal integrity is impaired in eosinophilic esophagitis (EoE) and it has been suggested that the duodenal permeability is increased. The absence of food allergens may restore the integrity. The aims of this study were to assess duodenal permeability in EoE and to evaluate the effect of an elemental diet on the esophageal and duodenal integrity.

METHODS

In this prospective study 17 adult EoE patients and 8 healthy controls (HC) were included. Esophageal biopsy specimens were sampled before and after 4 weeks of elemental diet to measure eosinophil counts and gene expression of tight junction and barrier integrity proteins. Esophageal and duodenal impedance were measured by electrical tissue impedance spectroscopy and Ussing chambers were used to measure transepithelial resistance (TER) and transepithelial molecule flux. Small intestinal permeability was measured using a test, measuring lactulose/mannitol (L/M) ratios.

RESULTS

In EoE patients, the esophageal but not the duodenal integrity was impaired, compared with HC. We observed no significant difference between L/M ratios of HC and EoE patients. After diet, eosinophil counts decreased significantly, which was paralleled by normalization of esophageal impedance and transepithelial molecule flux. The esophageal TER improved significantly, but did not reach values seen in HC. Esophageal expression of genes encoding for barrier integrity proteins filaggrin and desmoglein-1 was impaired at baseline and restored after diet.

CONCLUSIONS

An elemental diet restores esophageal integrity, suggesting that it is at least partly secondary to allergen exposure. Duodenal integrity seems not to be affected in EoE, and possibly plays a minor role in its pathophysiology.

Eosinophilic esophagitis in an octogenarian: A case report and review of the literature

INTRODUCTION

Eosinophilic esophagitis (EoE) is a chronic, immune/antigen-mediated disease characterized clinically by symptoms related to esophageal dysfunction and histologically by a marked eosinophilic infiltrate in the esophageal mucosa. What was once considered a rare disease has nowadays become one of the most frequent esophageal diseases in the Western countries, occupying a place just next to the gastroesophageal reflux disease. EoE etiology and pathogenesis remain largely unknown, although most studies consider that allergic and genetic factors play the most important role.

METHODS

We report the case of EoE in an elderly male (octogenarian), giving a brief review of the current data related to epidemiology, pathogenesis, diagnosis, and treatment of the disease.

RESULTS

Dysphagia to solid foods was the leading symptom, and endoscopic findings included white exudates, longitudinal furrows, and concentric mucosal rings, all suggestive for EoE. Diagnosis relied on histological findings in esophageal mucosal biopsies (>30 eosinophils per high power field).He was treated with topical steroids for 8 weeks, symptoms improved gradually and the patient remained in remission at the 8-month follow-up.

CONCLUSION

This case emphasizes that EoE may occur in very old patients and gastroenterologists should have a high index of suspicion of this disorder in any elderly with dysphagia and endoscopic relevant features.

Role of food and aeroallergen sensitization in eosinophilic esophagitis in adults

BACKGROUND

Evaluation of IgE-mediated food sensitivity is frequently performed for patients with eosinophilic esophagitis (EoE). However, the clinical relevance of identifying IgE-mediated sensitivity to foods in adults is unclear.

OBJECTIVE

To determine whether EoE associated with food or aeroallergen sensitivity represents a phenotype of EoE with distinct clinical or biological features.

METHODS

A medical record review identified 257 patients with a diagnosis of EoE evaluated in the adult allergy clinic at the University of Wisconsin Hospital and Clinics from 2008 to 2013. Patient records were reviewed to capture measures of disease severity, endoscopy results, pathology reports, allergy testing, medical management and patient-reported outcomes.

RESULTS

Evaluation of food sensitization with skin prick testing and/or serum IgE was performed for 93% of patients. Sensitization to at least 1 food was identified in 54% of patients who were more likely to report concomitant asthma, allergic rhinitis, eczema, and/or food allergy compared with nonfood sensitive patients. Aeroallergen sensitivity was identified in 87% of patients tested. Clinical characteristics, including EoE symptoms, disease severity, endoscopic findings, peripheral eosinophilia, and patient-reported outcomes, did not differ between food sensitive and non-food sensitive patients. However, on endoscopy, aeroallergen sensitive patients were more likely to have strictures and less likely to exhibit felinization compared with non-aeroallergen sensitized patients.

CONCLUSION

Adults with EoE and IgE-mediated food sensitivity are not phenotypically different than non-food sensitive patients. There is no clear clinical utility in identifying food sensitivity in adults with EoE. Further studies are needed to determine whether aeroallergen sensitivity represents a distinct phenotype of EoE.

Current Management of Eosinophilic Esophagitis 2015

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition characterized by esophageal dysfunction and eosinophilic infiltrate (≥15/hpf) in the esophageal epithelium and the absence of other potential causes of eosinophilia. The prevalence is increasing and is the most common cause of solid food dysphagia in children and young adults. This article will review the diagnosis and management of EoE based on consensus conferences, systematic reviews, and meta-analysis and highlights seminal studies in our evolving treatment of this disease. However, all answers are not available and I will remark about the lessons learned in my clinical practice seeing EoE patients over the last 25 years. The complicated etiology of the complaint of dysphagia in EoE patients will be reviewed. The importance of utilizing endoscopy, biopsies, and barium esophagram to help define the 2 phenotypes (inflammatory, fibrostenosis) of EoE will be highlighted. The controversy about PPI-responsive esophageal eosinophilia will be discussed and contrasted with idiopathic EoE. Finally, the 3 treatment options for EoE (drugs, diet, dilation) will be reviewed in detail and a useful clinical management algorithm presented.

Should wheat, barley, rye, and/or gluten be avoided in a 6-food elimination diet?

Eosinophilic esophagitis (EoE), a food antigen-mediated disease, is effectively treated with the dietary elimination of 6 foods commonly associated with food allergies (milk, wheat, egg, soy, tree nuts/peanuts, and fish/shellfish). Because wheat shares homologous proteins (including gluten) with barley and rye and can also be processed with these grains, some clinicians have suggested that barley and rye might also trigger EoE as a result of cross-reaction and/or cross-contamination with wheat. In this article, we discuss the theoretical risks of cross-reactivity and cross-contamination among wheat, barley, and rye proteins (including gluten); assess common practices at EoE treatment centers; and provide recommendations for dietary treatment and future studies of EoE.

Broide DH, Aceves SS. The TGFβ1 Promoter SNP C-509T and Food Sensitization Promote Esophageal Remodeling in Pediatric Eosinophilic Esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic antigen mediated disease associated with substantial esophageal remodeling and fibrosis. The functional TGFβ1 promoter SNP C-509 associates with renal fibrosis and asthma. The effect of TGFβ1 genotype and EoE severity or potential gene-environment interactions have not been previously reported in EoE.

METHODS

Genotype at TGFβ1 C-509T and remodeling was analyzed in 144 subjects with EoE. The severity of remodeling and inflammation was analyzed in the context of IgE sensitization to food antigens and C-509T genotype.

RESULTS

The TGFβ1 promoter C-509 genotypes CC, CT, and TT were 35%, 52%, and 13%, respectively. Sixty-six percent of subjects were sensitized to foods by positive skin prick test (SPT) or serum specific IgE. TT genotype subjects had significantly more TGFβ1 (CC subjects = 1300 per mm2; TT = 2250 per mm2) (p<0.05) and tryptase (CC subjects = 145 per mm2: TT = 307 per mm2) (p<0.05) positive cells and higher epithelial remodeling scores (2.4 vs 3.7, p<0.001) than CC subjects. The differences in TGFβ1 and tryptase positive cells as well as fibrosis were significantly increased when there was concurrent food sensitization. Food sensitization alone did not associate with any parameters of inflammation or remodeling.

CONCLUSIONS

Our data support a gene-environment interaction between food and genotype at C-509 that modulates disease severity in EoE. Since EoE subjects often continue to consume foods to which they are sensitized, these findings may have clinical relevance for disease management.

Recent research advances in eosinophilic esophagitis

PURPOSE OF REVIEW

Eosinophilic esophagitis (EoE) is a chronic allergic disease triggered by food allergens with an increasing prevalence. This review highlights recent research advances in EoE with a focus on the literature of the past 18 months.

RECENT FINDINGS

The incidence of EoE in the black population is higher than previously suggested. A novel locus spanning CAPN14 is associated with EoE. Diagnostic tests utilizing an analysis of EoE-specific transcriptome have been improved. Standardized EoE symptom score systems have been established. Treatment trials show the promise and limitations of allergen avoidance, antiinflammatory reagents, and anti-interleukin-13 antibodies. Insights into disease mechanisms highlight the role of invariant natural killer T cells and group 2 innate immune cells. Epithelial barrier protein desmoglein 1, bone morphogenetic protein antagonist follistatin, neurotrophic tyrosine kinase receptor type 1, and CAPN14 have been defined as new potential therapeutic targets in EoE as regulators of the inflammatory interleukin-13-axis. The role of IgG4 in the disease mechanisms has been suggested.

SUMMARY

Genetic predisposition influenced by environmental factors increases EoE susceptibility. Research identifying the critical events leading to allergen sensitization and the esophagus-specific responses that drive EoE is evolving, and will lead to a better understanding of EoE and new therapeutic approaches for the disease.

Eosinophilic Esophagitis

Once considered a rare condition, eosinophilic esophagitis is now one of the most common conditions diagnosed during the assessment of feeding problems in children and during the evaluation of dysphagia and food impaction in adults. The entity exists worldwide but has been most extensively studied in Western countries, where its prevalence has been estimated to be 0.4% among all children and adults. Whether eosinophilic esophagitis is truly a new disease or simply a recently recognized one is uncertain. In this review, we consider the diagnostic criteria, pathophysiological and clinical features, and treatment of this increasingly prevalent disease.

Elimination and elemental diet therapy in eosinophilic oesophagitis

Eosinophilic oesophagitis (EoE) is a chronic immune-mediated disorder of the oesophagus. The incidence of EoE has been raised substantially and EoE has recently become the most prevalent cause of dysphagia among the adolescents. Food and aeroallergens are believed to play a major role in the pathogenesis. Current treatment includes topical steroids and dietary therapy. Dietary therapy with elimination of causative allergens could provide a durable long-term solution. Dietary therapy in EoE consists of in elemental and empiric elimination diets. Elemental diet with amino acid-based formula is most effective in achieving disease remission but poor taste makes adherence challenging. Empiric elimination diet based on avoidance of most common food allergens offers moderate response rates, the usefulness of allergy test-directed elimination diets is questioned by low response rates. In conclusion, dietary treatments for EoE seem promising, but further refinement is required before it can become standard care.

Increased Risk of Esophageal Eosinophilia and Eosinophilic Esophagitis in Patients With Active Celiac Disease on Biopsy

BACKGROUND & AIMS

The possible association between eosinophilic esophagitis (EoE) and celiac disease is controversial because prior results have been contradictory. We aimed to determine the relationship between EoE and celiac disease among patients with concomitant esophageal and duodenal biopsies.

METHODS

We conducted a cross-sectional study in a U.S. national pathology database by using data from January 2009 through June 2012. Our primary case definition was defined by the presence of esophageal eosinophilia with ≥15 eosinophils per high-power field. The crude and adjusted (for age and sex) odds of esophageal eosinophilia for patients with active celiac disease were compared with those without celiac disease. Sensitivity analyses were performed by using more stringent case definitions and by estimating the associations between celiac disease and reflux esophagitis and celiac disease and Barrett's esophagus.

RESULTS

Of 292,621 patients in the source population, 88,517 with both esophageal and duodenal biopsies were studied. Four thousand one hundred one (4.6%) met criteria for EoE, and 1203 (1.4%) met criteria for celiac disease. Odds of EoE were 26% higher in patients with celiac disease than in patients without celiac disease (adjusted odds ratio [aOR], 1.26; 95% confidence interval [CI], 0.98-1.60). The magnitude of association varied according to EoE case definition, but all definitions showed a weak positive association between the 2 conditions. There was no association between celiac disease and reflux esophagitis (aOR, 0.95; 95% CI, 0.85-1.07) or Barrett's esophagus (aOR, 0.89; 95% CI, 0.69-1.14) and celiac disease.

CONCLUSIONS

There is a weak increase in EoE in patients with celiac disease. This association strengthened with increasingly stringent definitions of EoE and was not observed for other esophageal conditions. In patients with celiac disease, concomitant EoE should be considered in the correct clinical setting.

Eosinophils in Gastrointestinal Disorders: Eosinophilic Gastrointestinal Diseases, Celiac Disease, Inflammatory Bowel Diseases, and Parasitic Infections

The gastrointestinal (GI) tract provides an intriguing organ for considering the eosinophil's role in health and disease. The normal GI tract, except for the esophagus, is populated by eosinophils that are present throughout the mucosa, raising the possibility that eosinophils participate in innate mechanisms of defense. However, data from clinical studies associates increased numbers of eosinophils with inflammatory GI diseases, prompting concerns that eosinophils may have a deleterious effect on the gut. We present clinical features of 4 disease processes that have been associated with eosinophilia and suggest areas requiring investigation as to their clinical significance and scientific relevance.

Molecular, genetic, and cellular bases for treating eosinophilic esophagitis

Eosinophilic esophagitis (EoE) was historically distinguished from gastroesophageal reflux disease on the basis of histology and lack of responsiveness to acid suppressive therapy, but it is now appreciated that esophageal eosinophilia can respond to proton pump inhibitors. Genetic and environmental factors contribute to risk for EoE, particularly early-life events. Disease pathogenesis involves activation of epithelial inflammatory pathways (production of eotaxin-3 [encoded by CCL26]), impaired barrier function (mediated by loss of desmoglein-1), increased production and/or activity of transforming growth factor-β, and induction of allergic inflammation by eosinophils and mast cells. Susceptibility has been associated with variants at 5q22 (TSLP) and 2p23 (CAPN14), indicating roles for allergic sensitization and esophageal specific protease pathways. We propose that EoE is a unique disease characterized by food hypersensitivity; strong hereditability influenced by early-life exposures and esophageal-specific genetic risk variants; and allergic inflammation and that the disease is remitted by disrupting inflammatory and T-helper type 2 cytokine-mediated responses and through dietary elimination therapy.

Review article: the diagnosis and management of food allergy and food intolerances

BACKGROUND

Adverse reactions to food include immune mediated food allergies and non-immune mediated food intolerances. Food allergies and intolerances are often confused by health professionals, patients and the public.

AIM

To critically review the data relating to diagnosis and management of food allergy and food intolerance in adults and children.

METHODS

MEDLINE, EMBASE and the Cochrane Database were searched up until May 2014, using search terms related to food allergy and intolerance.

RESULTS

An estimated one-fifth of the population believe that they have adverse reactions to food. Estimates of true IgE-mediated food allergy vary, but in some countries it may be as prevalent as 4-7% of preschool children. The most common food allergens are cow's milk, egg, peanut, tree nuts, soy, shellfish and finned fish. Reactions vary from urticaria to anaphylaxis and death. Tolerance for many foods including milk and egg develops with age, but is far less likely with peanut allergy. Estimates of IgE-mediated food allergy in adults are closer to 1-2%. Non-IgE-mediated food allergies such as Food Protein-Induced Enterocolitis Syndrome are rarer and predominantly recognised in childhood. Eosinophilic gastrointestinal disorders including eosinophilic oesophagitis are mixed IgE- and non-IgE-mediated food allergic conditions, and are improved by dietary exclusions. By contrast food intolerances are nonspecific, and the resultant symptoms resemble other common medically unexplained complaints, often overlapping with symptoms found in functional disorders such as irritable bowel syndrome. Improved dietary treatments for the irritable bowel syndrome have recently been described.

CONCLUSIONS

Food allergies are more common in children, can be life-threatening and are distinct from food intolerances. Food intolerances may pose little risk but since functional disorders are so prevalent, greater efforts to understand adverse effects of foods in functional disorders are warranted.

Transcriptome analysis of proton pump inhibitor-responsive esophageal eosinophilia reveals proton pump inhibitor-reversible allergic inflammation

BACKGROUND

Esophageal eosinophilia can be proton pump inhibitor (PPI) resistant or responsive, representing 2 entities known as eosinophilic esophagitis (EoE) and PPI-responsive esophageal eosinophilia (PPI-REE), respectively. Although they present with similar clinical features, EoE is accepted to be an antigen-driven, TH2-associated allergic disorder, whereas the cause of PPI-REE remains a mystery.

OBJECTIVE

In this study, our aim was to investigate the pathogenesis of PPI-REE by using a recently described EoE diagnostic panel (EDP) composed of a set of 94 esophageal transcripts and to determine whether PPI therapy reverses any esophageal transcriptional abnormalities.

METHODS

We evaluated the EDP signature in biopsy samples obtained from adult and pediatric patients with PPI-REE from 4 institutions and compared the pre- and post-PPI therapy expression profiles of these subjects with those of patients with active EoE.

RESULTS

The EDP differentiated patients with EoE from control subjects with 100% accuracy among the 4 clinical sites. Bioinformatics analysis revealed largely overlapping transcriptomes between patients with PPI-REE and those with EoE, including the genes for eosinophil chemotaxis (eotaxin 3, CCL26), barrier molecules (desmoglein 1, DSG1), tissue remodeling (periostin, POSTN), and mast cells (carboxypeptidase A, CPA3). PPI monotherapy alone almost completely reversed the allergic inflammatory transcriptome of patients with PPI-REE. Furthermore, we identified a set of candidate genes to differentiate patients with EoE from those with PPI-REE before treatment.

CONCLUSION

These findings provide definitive evidence that PPI-REE is a disease entity with significant molecular overlap with EoE, suggesting that many patients with PPI-REE represent a continuum of the same pathogenic allergic mechanisms that underlie EoE and thus might constitute a subphenotype of patients with EoE. The ability of PPI therapy to nearly entirely reverse gene expression associated with PPI-REE, particularly that associated with classic features of allergic inflammation, provides new insight into potential disease etiology and management strategies for patients with significant esophageal eosinophilia.

Elimination diets in the management of eosinophilic esophagitis

Eosinophilic esophagitis, an increasingly recognized chronic inflammatory disorder isolated to the esophagus, is triggered by an abnormal allergic response to dietary antigens. Current treatment includes swallowed topical steroids and dietary modification, which aim to resolve symptoms and prevent long-term complications such as formation of strictures. The dietary approach has become more widely accepted because long-term steroid therapy is associated with potential risks. Dietary treatment includes elemental and elimination diets. An exclusive elemental diet, which requires replacement of all intact protein with amino acid-based formula, offers the best response of all available therapies, with remission in up to 96% of subjects proving it to be superior to all other available therapies including topical steroids. However, compliance with this approach is challenging because of poor taste and monotony. The high cost of formula and the associated psychosocial problems are additional drawbacks of this approach. Empiric and allergy test-directed elimination diets have gained popularity given that elimination of a limited number of foods is much easier and as such is more readily acceptable. There is a growing body of literature supporting this type of therapy in both children and adults. This paper reviews the evidence for all types of dietary therapy in eosinophilic esophagitis.

Diagnostic and therapeutic strategies for eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a recently recognized allergic disorder, characterized by eosophageal dysfunction, accumulation of ≥15 eosinophils/high-powered field, eosinophil microabssess, basal cell hyperplasia, extracellular eosinophilic granules in the esophageal epithelial mucosal biopsy and a lack of response to a 8-week proton pump inhibitor treatment. Despite the increased incidences and considerable progress made in understanding EoE pathogenesis, there are limited diagnostic and therapeutic options available for EoE. Currently, the only criterion for diagnosing EoE is repetitive esophageal endoscopic biopsies and histopathological evaluation. Antigen elimination or corticosteroid therapies are effective therapies for EoE but are expensive and have limitations, if continued in the long term. Hence, there is a great necessity for novel noninvasive diagnostic biomarkers that can easily diagnose EoE and assess effectiveness of therapy. Herein, we have provided an update on key molecules involved in the disease initiation, and progression and proposed novel noninvasive diagnostic molecules and strategies for EoE therapy.