An allergist's perspective to the evaluation of Eosinophilic Esophagitis

Amino Acid Profiling Identifies Disease-Specific Signatures in IgE-Mediated and Non-IgE-Mediated Food Allergy in Pediatric Patients with Atopic Dermatitis

An IgE-mediated food allergy (FA) in atopic dermatitis (AD) children should be easily differentiated from other immune-mediated adverse effects related to food. Specific IgEs for particular protein components has provided additional diagnostic value. However, component-resolved diagnostics (CRD) has not solved all diagnostic problems either. We analysed the serum profile of 42 amino acids (AAs) in 76 AD children aged 2-60 months with an IgE-mediated FA (n = 36), with a non-IgE-mediated FA (n = 15) and without an FA (n = 25) using high-performance liquid chromatography coupled with mass spectrometry (LC-MS/MS) and an aTRAQ kit. We identified homocitrulline (Hcit), sarcosine (Sar) and L-tyrosine (Tyr) as features that differentiated the studied groups (one-way ANOVA with least significant difference post hoc test). The Hcit concentrations in the non-IgE-mediated FA group were significantly decreased compared with the IgE-mediated FA group (p = 0.018) and the control group (p = 0.008). In AD children with a non-IgE-mediated FA, the Tyr levels were also significantly reduced compared with the controls (p = 0.009). The mean concentration of Sar was the highest in the non-IgE-mediated FA group and the lowest in the IgE-mediated FA group (p = 0.047). Future studies should elucidate the involvement of these AAs in the molecular pathway of IgE- and non-IgE-mediated allergic responses.

Primary eosinophilic gastrointestinal disorders and allergy: Clinical and therapeutic implications

Primary eosinophilic gastrointestinal disorders (EGID) are increasingly prevalent, immune‐mediated, chronic conditions which primarily affect pediatric and young adult patients, leading to substantial disease burden, and poor quality of life. EGID may either involve single portions of the gastrointestinal tract (i.e., esophagus, stomach, small bowel, and colon) or a combination. Their strong association with allergic disorders has been recently recognized, and although their shared pathophysiological basis remains partly elusive, this feature greatly impacts the diagnostic and treatment work‐up. We herein critically discuss the current knowledge on the association of EGID and allergic disorders, including atopic dermatitis, allergic rhinitis, allergic asthma, and food or drug allergy. In particular, we reviewed the literature focusing on their epidemiology, pathophysiological basis and mechanisms, and diagnostic strategies. Finally, we discuss the currently ongoing clinical trials targeting EGID and allergic diseases, including, among others the monoclonal antibodies dupilumab, mepolizumab, benralizumab, and lirentelimab.

Bidirectional associations between eosinophils, basophils, and lymphocytes with atopic dermatitis: A multivariable Mendelian randomization study

Background

Despite being prone to reverse causation and having unmeasured confounding factors, many clinical observational studies have highlighted the critical association between basophils, eosinophils, and lymphocytes and atopic dermatitis (AD). Whether these cells play a causal role in AD development remains uncertain.

Methods

Data were obtained from the UK Biobank and the Blood Cell Consortium, from a large publicly available genome-wide association study (GWAS) with more than 500,000 subjects of European ancestry and for AD from three independent cohorts with more than 700,000 subjects of European ancestry. We performed single-variable Mendelian randomization (SVMR), followed by multivariable Mendelian randomization (MVMR) to assess the total and direct effects of immune cell counts on AD risk.

Results

SVMR estimates showed that genetically predicted higher eosinophil [odds ratio (OR): 1.23, 95% confidence interval (CI): 1.17-1.29, p = 5.85E-16] and basophil counts (OR: 1.11, 95% CI: 1.03-1.19, p = 0.004) had an adverse effect on the risk of AD, while a higher lymphocyte count (OR: 0.93, 95% CI: 0.89-0.98, p = 0.006) decreased the risk. Reverse MR analysis showed higher basophil (beta: 0.04, 95% CI: 0.01-0.07, p = 0.014) and lower lymphocyte counts (beta: -0.05, 95% CI: -0.09 to -0.01, p = 0.021) in patients with AD. In MVMR, the effects of eosinophils (OR: 1.19, 95% CI: 1.09-1.29, p = 8.98E-05), basophils (OR: 1.19, 95% CI: 1.14-1.24, p = 3.72E-15), and lymphocytes (OR: 0.93, 95% CI: 0.89-0.98, p = 0.006) were still significant.

Discussion

Mendelian randomization (MR) findings suggest that an increase in the eosinophil and basophil counts and a decrease in the lymphocyte counts are potential causal risk factors for AD. These risk factors are independent of each other.

Review of eosinophilic oesophagitis in children and young people

Eosinophilic oesophagitis is a relapsing inflammatory disorder involving oesophagus identified over 30 years ago. Diagnosis is made by upper gastrointestinal endoscopy and oesophageal biopsies. There is huge variation in management practices across the globe. Therapeutic options include the use of proton pump inhibitors, topical steroids, and elimination diet. Biologics and immunomodulator drugs are being explored but not yet recommended in children. Long-term treatment may be required to control symptoms and to prevent complications such as fibrosis/stricture.Conclusion: Even though clinicians have better understanding of eosinophilic oesophagitis, further research is warranted in exploring the unmet needs of developing a highly sensitive non-invasive biomarker for its diagnosis and response to treatment along with a robust and easily deliverable therapeutic option. What is Known: •Incidence of eosinophilic oesophagitis has increased over the recent years. •Diagnostic confirmation requires upper gastrointestinal endoscopy and therapeutic options include elimination diet and/or topical steroids. What is New: •There is a lack of consensus ion management strategy with wide variation across the globe. •There is a need to develop a highly reliable and non-invasive biomarker to diagnose eosinophilic oesophagitis and to monitor the response to treatment.

Eosinophilic esophagitis during sublingual and oral allergen immunotherapy

PURPOSE OF REVIEW

The aim of this review is to discuss the current evidence regarding the development of eosinophilic esophagitis (EoE) in individuals undergoing oral and sublingual immunotherapy (SLIT) for both food and environmental allergens. Cumulative incidence of EoE in patients on allergen immunotherapy for peanut, milk, and egg is estimated.

RECENT FINDINGS

De novo development of EoE in patients undergoing oral and SLIT has been demonstrated on the scale of case reports and prospective randomized trials. However, few individuals with EoE-like symptoms during immunotherapy undergo endoscopy, and the long-term outcomes of immunotherapy-associated EoE are unknown.

SUMMARY

Evidence exists to suggest that allergen immunotherapy could place individuals at risk for the development of EoE, the true incidence of which may vary depending on antigen exposure and methods used to define the condition.

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.

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.

Eosinophilic esophagitis incidence in New Zealand: high but not increasing

Background and aim

Eosinophilic esophagitis (EoE) is an immune-mediated inflammatory condition of the esophagus. Recent literature has shown an increasing incidence of the disease. However, no epidemiological data exist regarding New Zealand rates of EoE. The disease is associated with atopy, and New Zealand's high rate of atopic disease means the disease may be important in our population. We carried out a retrospective study to describe the incidence of EoE in the Wellington region of New Zealand, as well as key histological and clinical factors associated with the disease.

Method

A search was made of laboratory and endoscopic databases in the Wellington region to identify all diagnosed cases in the five years between January 1, 2011, and December 31, 2015. Case notes were examined to determine the key demographic and clinical parameters in the cases. Incidence rates were calculated for each year, and the effects of age group and sex on the incidence rates were analyzed.

Result

We found 152 cases of EoE in the Wellington region with an annual incidence of 6.95 per 100,000 person/years. We found no evidence of a significant difference in incidence rates by year in our study population. There was a significantly lower incidence rate in those aged <16 compared to those aged ≥16 (RR=0.26). Males had a higher incidence rate than females with an estimated rate ratio of 2.45 (p<0.05).

Conclusion

Our results are in contrast to previous reports of increasing incidence rates and may reflect a leveling off of incidence. Further research is needed to determine whether the low incidence in our pediatric age group is due to ascertainment bias or due to a real difference in the epidemiology of EoE in NZ compared to other countries.

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.

Eosinophilic esophagitis in pediatric age, state of the art and review of the literature

Eosinophilic esophagitis (EoE) is a chronic immune-mediated relapsing disease caused by eosinophilic infiltration of the esophageal mucosa which is normally lacking these cells. EoE belongs to the group of the so called Eosinophilic Gastrointestinal Disorders (EGIDs). From a rare and unusual disease, EoE has become an emerging entity and in recent years its incidence and prevalence have increased all over the world, also in children. The pathogenesis is very complex and still not completely clear. Esophageal disfunction symptoms (e.g. dysphagia and food impaction) represent the typical manifestation of EoE and this condition could be difficult to recognize, more in pediatric age than in adults. Moreover, symptoms can often overlap with those of gastro-esophageal reflux disease (GERD), leading to a delayed diagnosis. EoE is often related to atopy and an allergological evaluation is recommended. Untreated EoE could provoke complications such as strictures, esophageal rings, narrowing of the esophagus. Diagnosis is confirmed by the demonstration in biopsy specimens obtained through upper endoscopy of eosinophilic inflammation (>15 for high powered field) of the esophageal mucosa and other histological features. Other tests could be useful not specifically for the diagnosis, but for the characterization of the subtype of EoE. Since EoE incidence and knowledge about physiopathology and natural history have increased, the goal of the review is to provide some helpful tools for the correct management in pediatric age together with an overview about epidemiology, pathogenesis, clinical, diagnosis and treatment of the disease.

Early Infant Risk Factors for Pediatric Eosinophilic Esophagitis

OBJECTIVES

Eosinophilic esophagitis (EoE) is an inflammatory, atopic disease of the esophagus without a clear etiology. Our objective was to identify exposures and conditions in early infancy associated with the development of EoE.

METHODS

A case-control study was performed using the Military Health System Database. Subjects diagnosed with EoE from October 2008 to September 2015 were matched 1:2 on age and sex. Early infant risk factors from the first 6 months of life were investigated.

RESULTS

A total of 1410 cases with EoE were matched to 2820 controls. The median (interquartile range) age at diagnosis of EoE was 4.2 years (2.1-7.2) and 68.7% were boys. Proton pump inhibitors (adjusted odds ratio [aOR], 2.73; 95% confidence interval [CI] 1.93-3.88), histamine-2 receptor antagonists (aOR, 1.64; 95% CI 1.27-2.13), and antibiotics (aOR, 1.31; 95% CI 1.10-1.56) were associated with EoE. Prematurity (aOR, 1.46; 95% CI 1.12-1.89) and early manifestations of atopic disease such as milk protein allergy (aOR, 2.37; 95% CI 1.26-4.44) and eczema (aOR, 1.97; 95% CI 1.64-2.36) were related to increased odds for EoE. Erythema toxicum in infancy was strongly associated with a diagnosis of EoE (aOR 3.52; 95% CI 1.03-12.04). Infants with feeding difficulty (aOR, 1.45; 95% CI 1.18-1.77) and gastroesophageal reflux disease (aOR, 1.79; 96% CI 1.43-2.26) were also at increased risk for EoE.

CONCLUSIONS

Acid-blocking medications and antibiotics during infancy were associated with later diagnosis of EoE. Erythema toxicum neonatorum, an eosinophilic immune phenomenon, was strongly associated with EoE. Identifying early infant risk factors for EoE may help to risk stratify the need for endoscopy.

Pediatric Eosinophilic Esophagitis Endotypes: Are We Closer to Predicting Treatment Response?

Eosinophilic esophagitis (EoE) is a chronic, food antigen-driven gastrointestinal disease that is characterized by esophageal eosinophilia. Currently, there are no Food and Drug Administration (FDA)-approved treatments for EoE, but the two most commonly prescribed therapies include topical corticosteroids and food elimination diets. Clinical trials have revealed a significant proportion of cases that are resistant to topical corticosteroids, and although we define EoE as a food antigen-driven disease, not all patients with EoE respond to elimination diets or even elemental diets. The varied response to treatments highlights the heterogeneity of EoE and the need for new treatment strategies. Despite the clinical differences in treatment response, predicting the outcome remains difficult since factors including age, histologic severity at diagnosis, atopic history, and anthropometrics are not predictive of treatment response. In our practice at an academic pediatric referral center, we observe distinct clinical EoE phenotypes, including cases with atopy, connective tissue disorders, or responsiveness to a proton pump inhibitor. Similar to the work in progress with asthma, stratification of patients with EoE by clinical phenotypes and/or molecular endotypes will likely assist with therapy selection and prediction of natural history. Molecular analysis with gene expression panels also shows promise in helping us classify patients based on molecular endotypes. In additional to the clinical and molecular classifications, more accurate histologic diagnostic criteria for EoE may help us tease out small differences between patient cohorts. Despite the leaps in knowledge over the past decade regarding EoE pathogenesis, it remains a challenge to predict the response to treatment. Future studies focused on molecular, genetic, and immunologic analyses of larger patient cohorts are needed to assist in identifying EoE phenotypes and endotypes as we attempt to improve patient outcomes in pediatric EoE.

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 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.

An algorithm for the classification of mRNA patterns in eosinophilic esophagitis: Integration of machine learning

BACKGROUND

Diagnostic evaluation of eosinophilic esophagitis (EoE) remains difficult, particularly the assessment of the patient's allergic status.

OBJECTIVE

This study sought to establish an automated medical algorithm to assist in the evaluation of EoE.

METHODS

Machine learning techniques were used to establish a diagnostic probability score for EoE, p(EoE), based on esophageal mRNA transcript patterns from biopsies of patients with EoE, gastroesophageal reflux disease and controls. Dimensionality reduction in the training set established weighted factors, which were confirmed by immunohistochemistry. Following weighted factor analysis, p(EoE) was determined by random forest classification. Accuracy was tested in an external test set, and predictive power was assessed with equivocal patients. Esophageal IgE production was quantified with epsilon germ line (IGHE) transcripts and correlated with serum IgE and the T_h2-type mRNA profile to establish an IGHE score for tissue allergy.

RESULTS

In the primary analysis, a 3-class statistical model generated a p(EoE) score based on common characteristics of the inflammatory EoE profile. A p(EoE) ≥ 25 successfully identified EoE with high accuracy (sensitivity: 90.9%, specificity: 93.2%, area under the curve: 0.985) and improved diagnosis of equivocal cases by 84.6%. The p(EoE) changed in response to therapy. A secondary analysis loop in EoE patients defined an IGHE score of ≥37.5 for a patient subpopulation with increased esophageal allergic inflammation.

CONCLUSIONS

The development of intelligent data analysis from a machine learning perspective provides exciting opportunities to improve diagnostic precision and improve patient care in EoE. The p(EoE) and the IGHE score are steps toward the development of decision trees to define EoE subpopulations and, consequently, will facilitate individualized therapy.

Integrin αM activation and upregulation on esophageal eosinophils and periostin-mediated eosinophil survival in eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an increasingly recognized allergic disease associated with dysphagia and esophageal fibrosis. We aimed to determine expression patterns of specific eosinophil integrins that promote eosinophilic infiltration of the esophageal epithelium, and to determine how key EoE-related cytokines influence eosinophil activation and survival. Esophageal and peripheral eosinophils were isolated from 20 adult subjects with EoE for immunophenotyping and integrin profiling using multicolor flow cytometry and immunohistochemistry. Expression signatures of eosinophil integrins were further assessed by immunohistochemistry using serial sections of esophageal biopsy specimens. Purified eosinophils were used to assess the effect of EoE-relevant cytokines and recombinant periostin on expression of known eosinophil integrins and eosinophil survival and activation. We found that resting eosinophils express high levels of the β2-pairing integrins αL and αM, and lower levels of α4, α6 and α4β7. The migration of peripheral eosinophils to the esophagus is characterized by the specific induction of αM, and a significant increase in the proportion of αM in high-activity conformation. Periostin, a secreted extracellular matrix protein that is significantly overexpressed in EoE, enhances eosinophil survival, and this effect is mediated by αM interaction. Integrin αM is a specific marker of activated tissue eosinophils in EoE, and promotes eosinophil survival through interactions with periostin. The ability of αMβ2 to mediate eosinophil tissue residency via periostin represents a key mechanism for disease development and a potential therapeutic target in EoE.

Eosinophilic Esophagitis Is an Underlying Cause for Gastrointestinal Concerns in Children

Eosinophilic esophagitis (EoE) is a chronic immune antigen-mediated disorder characterized by symptoms of esophageal dysfunction in combination with dense esophageal eosinophilia. The clinical presentation of EoE can vary depending on children's age and their ability to report symptoms, therefore a high index of suspicion for EoE is required because children and teenagers may develop coping strategies around eating. The development of symptoms measurement tools in EoE assists in not only assessing symptoms, but also coping strategies children may have developed. While the diagnosis of EoE requires endoscopic evaluation with histologic assessment of esophageal mucosal biopsy samples, several emerging methods to assess and survey the esophageal mucosa have been developed. Advances in the field to better understand the natural history, clinical and molecular features of phenotypes in EoE will be important in considering novel therapeutic options and assessing outcomes.

Microbiome and its impact on gastrointestinal atopy

The prevalence of allergic conditions has continuously increased in the last few decades in Westernized countries. A dysbiotic gut microbiome may play an important role in the development of allergic diseases. Genetic, environmental, and dietary factors may alter the commensal microbiota leading to inflammatory dysregulation of homeostasis. Murine and human studies have begun to elucidate the role of the microbiota in the pathogenesis of atopic diseases including asthma, atopic dermatitis, and food allergies. However, the role of the microbiome in most eosinophilic gastrointestinal diseases (EGIDs) is not yet known. This review provides an overview of what is currently known about the development of tolerance from both molecular and clinical standpoints. We also look at the gut-specific microbiome and its role in atopic conditions with the hope of applying this knowledge to the understanding, prevention, and treatment of EGIDs, particularly EoE.

Eosinophilic esophagitis: published evidences for disease subtypes, indications for patient subpopulations, and how to translate patient observations to murine experimental models

Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder of the esophagus and commonly classified as a Th2-type allergy. Major advances in our understanding of the EoE pathophysiology have recently been made, but clinicians struggle with highly unpredictable therapy responses indicative of phenotypic diversity within the patient population. Here, we summarize evidences for the existence of EoE subpopulations based on diverse inflammatory characteristics of the esophageal tissue in EoE. Additionally, clinical characteristics of EoE patients support the concept of disease subtypes. We conclude that clinical and experimental evidences indicate that EoE is an umbrella term for conditions that are unified by esophageal eosinophilia but that several disease subgroups with various inflammatory esophageal patterns and/or different clinical features exist. We further discuss strategies to study the pathophysiologic differences as observed in EoE patients in murine experimental EoE. Going forward, models of EoE that faithfully mimic EoE subentities as defined in humans will be essential because mechanistic studies on triggers which regulate the onset of diverse EoE subpopulations are not feasible in patients. Understanding how and why different EoE phenotypes develop will be a first and fundamental step to establish strategies that integrate individual variations of the EoE pathology into personalized therapy.