The Role of the Environment in Eosinophilic Esophagitis

Climate Change and Food Allergy

The role of environmental factors including climate change and consequent influences of air pollution on food allergy remains less explored compared with impacts on allergic rhinitis and asthma. In this review, we discuss the epithelial barrier hypothesis as a proposed mechanism of food allergy development that may be relevant in this context. We also discuss existing studies that provide insight into the intricate relationship between food allergy and climate-related environmental factors.

Food allergy: cause or consequence of pediatric eosinophilic esophagitis? Potential implications of ultraprocessed foods in prevention and management

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated disease characterized by eosinophilic infiltration, leading to esophageal dysfunction, inflammation, and fibrotic remodeling. In the last few decades, there has been an increased prevalence of EoE at an alarming rate in the pediatric age. The pathogenesis of EoE is still largely undefined, and this limits the definition of effective strategies for the prevention and management of this condition. EoE is considered a multifactorial disease arising from a negative interaction between environmental factors and genetic background, causing an impaired esophageal epithelial barrier with subsequent abnormal allergen exposure activating type 2 (Th2) inflammation. Food antigens have been suggested as key players in Th2 inflammation in pediatric patients with EoE, but emerging evidence suggests a potential role of other dietary factors, including ultraprocessed foods, as possible triggers for the occurrence of EoE. In this paper, we discuss the potential role of these dietary factors in the development of the disease, and we propose a new approach for the management of pediatric patients with EoE.

Differences between childhood- and adulthood-onset eosinophilic esophagitis: An analysis from the EoE connect registry

BACKGROUND

Direct comparisons of childhood- and adulthood-onset eosinophilic esophagitis (EoE) are scarce.

AIM

To compare disease characteristics, endoscopic and histological features, allergic concomitances and therapeutic choices across ages.

METHODS

Cross-sectional analysis of the EoE CONNECT registry.

RESULTS

The adulthood-onset cohort (those diagnosed at ≥18y) comprised 1044 patients and the childhood-onset cohort (patients diagnosed at <18 y), 254. Vomiting, nausea, chest and abdominal pain, weight loss, slow eating and food aversion were significantly more frequent in children; dysphagia, food bolus impaction and heartburn predominated in adults. A family history of EoE was present in 16% of pediatric and 8.2% of adult patients (p<0.001). Concomitant atopic diseases did not vary across ages. Median±IQR diagnostic delay (years) from symptom onset was higher in adults (2.7 ± 6.1) than in children (1 ± 2.1; p<0.001). Esophageal strictures and rings predominated in adults (p<0.001), who underwent esophageal dilation more commonly (p = 0.011). Inflammatory EoE phenotypes were more common in children (p = 0.001), who also presented higher eosinophil counts in biopsies (p = 0.015) and EREFS scores (p = 0.017). Despite PPI predominating as initial therapy in all cohorts, dietary therapy and swallowed topical corticosteroids were more frequently prescribed in children (p<0.001).

CONCLUSIONS

Childhood-onset EoE has differential characteristics compared with adulthood-onset, but similar response to treatment.

Mechanisms and clinical management of eosinophilic oesophagitis: an overview

Since the first description of eosinophilic oesophagitis (EoE) less than three decades ago, we have observed a striking increase in the number of patients diagnosed with EoE and the understanding of its clinical and immunopathogenic background. Nonetheless, a plethora of open questions await elucidation. In this Review, we discuss the current state of knowledge regarding the underlying mechanisms, particularly environmental factors and their interaction with genetic susceptibility. Subsequently, we discuss how to translate these factors into the diagnostic and therapeutic management of this chronic, immune-mediated disorder. Finally, we dissect the still long list of unmet needs, such as reasons for and handling refractory EoE and atypical clinical presentations. These open questions can guide us through future research steps and potentially foster reconsideration of the diagnostic guidelines of EoE.

IgG4+ cells are increased in the gastrointestinal tissue of pediatric patients with active eosinophilic gastritis and duodenitis and decrease in remission

BACKGROUND

Recent studies have shown that IgG4 is increased in the esophageal tissue of eosinophilic esophagitis patients, including the presence of IgG4+ plasma cells.

AIMS

Our aim was to determine whether IgG4 is elevated in the gastric or duodenal tissue of pediatric patients with eosinophilic gastritis or duodenitis (EoG or EoD).

METHODS

This was a retrospective single center study. Pediatric patients were characterized as having active EoG, EoD, or as controls based on clinical symptoms and histologic features. Immunohistochemistry for IgG4 was performed in gastric and duodenal tissue, and peak IgG4+ cells were compared between groups and after treatment.

RESULTS

The frequency of IgG4+ cells was significantly higher in patients with EoG and EoD compared to controls in the stomach [EoG 6.5 cells/hpf (3.6-10.9), control 0 cells/hpf (0-0.7), p<0.0001] and duodenum [EoD 7.5 cells/hpf (2.8-37), control 0.5 cells/hpf (0.3-1.3), p<0.001)] respectively, and positively correlated with eosinophil counts (stomach: r 0.74, p<0.0001; duodenum: r 0.57, p<0.0001). The amount of tissue IgG4 was significantly decreased in patients in remission but not in persistently active disease.

CONCLUSIONS

These data suggest local tissue production of IgG4 may be a universal feature of eosinophilic gastrointestinal disease that tracks with disease activity.

Breaking down the complex pathophysiology of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic and progressive immune-mediated disease of the esophagus associated with antigen-driven type 2 inflammation and symptoms of esophageal dysfunction. Our understanding of EoE pathophysiology has evolved since its initial recognition more than 20 years ago and has translated into diagnostic and novel therapeutic approaches that are affecting patient care. The mechanisms underlying disease development and progression are influenced by diverse factors, such as genetics, age, allergic comorbidities, and allergen exposures. Central to EoE pathophysiology is a dysregulated feed-forward cycle that develops between the esophageal epithelium and the immune system. Allergen-induced, type 2-biased immune activation by the esophageal epithelium propagates a cycle of impaired mucosal barrier integrity and allergic inflammation, eventually leading to tissue remodeling and progressive organ dysfunction. Herein, we review the current understanding of fundamental pathophysiological mechanisms contributing to EoE pathogenesis.

Environmental Pollutants Are Associated With Irritable Bowel Syndrome in a Commercially Insured Cohort of California Residents

BACKGROUND AND AIMS

Prior studies have linked environmental pollutants with gastrointestinal (GI) diseases. Here, we quantify the relationships between 7 pollutants and the zip code-level incidence of irritable bowel syndrome (IBS), functional dyspepsia, inflammatory bowel diseases (IBDs), and eosinophilic esophagitis (EoE) in California.

METHODS

Claims in Optum's Clinformatics Data Mart were linked with environmental exposures in California, derived from CalEnviroScreen 3.0. We identified adult patients with new diagnoses of each GI disease, and estimated claims-derived, zip code-level disease incidence rates. Two study periods were considered: 2009-2014 (International Classification of Diseases-Ninth Revision era) and 2016-2019 (International Classification of Diseases-Tenth Revision [ICD-10] era). Multivariable negative binomial regression models were used to test associations between 7 pollutants (ozone, particulate matter <2.5 μm [PM2.5], diesel emissions, drinking water contaminants, pesticides, toxic releases from industrial facilities, traffic density) and zip code-level incidence of the GI diseases along with a negative control outcome, adjusting for numerous potential confounders.

RESULTS

Zip code-level IBS incidence was associated with PM2.5 (P < .001 in both eras) and airborne toxic releases from facilities (P < .001 in both eras). An increase of 1 μg/m³ in PM2.5 or 1% in toxic releases translates to an increase in the IBS incidence rate of about 0.02 cases per 100 person-years. Traffic density and drinking water contaminant exposures were also associated with increasing IBS incidence, but these associations were not significant in both eras. Similarly, exposure to PM2.5, drinking water contaminants and airborne toxic releases from facilities were associated with functional dyspepsia incidence, though not in both eras. No significant associations were noted between pollutants and IBD or EoE incidence.

CONCLUSION

Exposure to PM2.5 and airborne toxic releases from facilities are associated with higher IBS incidence among a cohort of commercially insured Californians. Environmental pollutant exposure was not associated with the incidence of IBDs and EoE in this cohort.

Characterization of Eosinophilic Esophagitis From the European Pediatric Eosinophilic Esophagitis Registry (pEEr) of ESPGHAN

OBJECTIVES

Few pediatric data on phenotypic aspects of eosinophilic esophagitis (EoE) are available. The pEEr registry was developed to prospectively characterize children with EoE from Europe and Israel.

METHODS

pEEr is an ongoing prospective registry enrolling children with esophageal eosinophilia (≥15 eos/HPF). Anonymized data were collected from 19 pediatric centers. Data regarding demographics, clinical manifestations, endoscopy, histology, and therapies were collected.

RESULTS

A total of 582 subjects (61% male) were analyzed. The median age at diagnosis was 10.5 years [interquartile range (IQR): 5.7-17.7], whereas the age at symptom onset was 9.2 years (IQR: 4.3-16.4), resulting in a median diagnostic delay of 1.2 years (IQR: 0.7-2.3). The diagnostic delay was longer below age <6 years. Shorter diagnostic delays were associated with the presence of food allergy or a family history for EoE. Symptoms varied by age with dysphagia and food impaction more common in adolescents, while vomiting and failure to thrive more common in younger children ( P < 0.001). Among endoscopic findings, esophageal rings were more common in adolescents, whereas exudates were more frequent in younger children( P < 0.001). Patients who responded to proton pump inhibitors (PPIs) were more likely to be older, males, and less often presented severe endoscopic findings. Patients unresponsive to PPIs received topical steroids (40%), elimination diet (41%), or a combined therapy (19%).

CONCLUSIONS

EoE findings vary according to age in pediatric EoE. Young children are commonly characterized by non-specific symptoms, atopic dermatitis, food allergy, and inflammatory endoscopic lesions. Adolescents usually have dysphagia or food impaction, fibrostenotic lesions, and a better PPI response.

Refractory eosinophilic esophagitis: what to do when the patient has not responded to proton pump inhibitors, steroids and diet

PURPOSE OF REVIEW

Management for patients with refractory eosinophilic esophagitis (EoE) remains a clinical challenge. This review aims to define refractory EoE, explore rates and reasons for nonresponse, and discuss the evidence that informs the approach to these patients.

RECENT FINDINGS

Many patients will fail first-line therapies for EoE. Longer duration of therapy can increase response rates, and initial nonresponders may respond to alternative first-line therapies. There are ongoing clinical trials evaluating novel therapeutics that hold promise for the future of EoE management. Increasingly, there is recognition of the contribution of oesophageal hypervigilance, symptom-specific anxiety, abnormal motility and oesophageal remodelling to ongoing clinical symptoms in patients with EoE.

SUMMARY

For refractory EoE, clinicians should first assess for adherence to treatment, adequate dosing and correct administration. Extending initial trials of therapy or switching to an alternative first-line therapy can increase rates of remission. Patients who are refractory to first-line therapy can consider elemental diets, combination therapy or clinical trials of new therapeutic agents. Patients with histologic remission but ongoing symptoms should be evaluated for fibrostenotic disease with EGD, barium esophagram or the functional luminal imaging probe (FLIP) and should be assessed for the possibility of oesophageal hypervigilance.

Accurate and timely diagnosis of Eosinophilic Esophagitis improves over time in Europe. An analysis of the EoE CONNECT Registry

Background

Poor adherence to clinical practice guidelines for eosinophilic esophagitis (EoE) has been described and the diagnostic delay of the disease continues to be unacceptable in many settings.

Objective

To analyze the impact of improved knowledge provided by the successive international clinical practice guidelines on reducing diagnostic delay and improving the diagnostic process for European patients with EoE.

Methods

Cross‐sectional analysis of the EoE CONNECT registry based on clinical practice. Time periods defined by the publication dates of four major sets of guidelines over 10 years were considered. Patients were grouped per time period according to date of symptom onset.

Results

Data from 1,132 patients was analyzed and median (IQR) diagnostic delay in the whole series was 2.1 (0.7‐6.2) years. This gradually decreased over time with subsequent release of new guidelines (p < 0.001), from 12.7 years up to 2007 to 0.7 years after 2017. The proportion of patients with stricturing of mixed phenotypes at the point of EoE diagnosis also decreased over time (41.3% vs. 16%; p < 0.001), as did EREFS scores. The fibrotic sub‐score decreased from a median (IQR) of 2 (1‐2) to 0 (0‐1) when patients whose symptoms started up to 2007 and after 2017 were compared (p < 0.001). In parallel, symptoms measured with the Dysphagia Symptoms Score reduced significantly when patients with symptoms starting before 2007 and after 2012 were compared. A reduction in the number of endoscopies patients underwent before the one that achieved an EoE diagnosis, and the use of allergy testing as part of the diagnostic workout of EoE, also reduced significantly over time (p = 0.010 and p < 0.001, respectively).

Conclusion

The diagnostic work‐up of EoE patients improved substantially over time at the European sites contributing to EoE CONNECT, with a dramatic reduction in diagnostic delay.

Pathophysiology of Non-IgE-Mediated Food Allergy

Non-IgE-mediated food allergies are a group of disorders characterized by subacute or chronic inflammatory processes in the gut. Unlike IgE mediated food allergies that may result in multi-organ system anaphylaxis, the non-IgE mediated food allergies primarily affect the gastrointestinal tract. This review outlines the clinical manifestations, epidemiology, pathophysiology, and management of non-IgE-mediated food allergies. An updated literature search of selected non-IgE-mediated food allergies was conducted for this review using PubMed database to the current year (2021). Reviewed disorders include food protein-induced enterocolitis syndrome (FPIES), food-protein enteropathy (FPE), food protein-induced allergic proctocolitis (FPIAP), and eosinophilic gastrointestinal disorders (EGIDs) such as eosinophilic esophagitis (EoE). While extensive gains have been made in understanding FPIES, FPIAP, FPE, and EoE, more information is needed on the pathophysiology of these food allergies. Similarities among them include involvement of innate immunity, T-lymphocyte processes, alteration of the intestinal lumen at the cellular level with the appearance of inflammatory cells and associated histologic changes, and specific cytokine profiles suggesting food-specific, T-cell, and immune-mediated responses. While FPIES and FPIAP typically resolve in early childhood, EGIDs typically do not. Emerging new therapies for EoE offer promise of additional treatment options. Further studies identifying the immunopathogenesis, associated biomarkers, and mechanisms of tolerance are needed to inform prevention, diagnosis and management.

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.