Primary eosinophilic gastrointestinal disorders and allergy: Clinical and therapeutic implications

Histological Outcomes of Pharmacological Interventions in Eosinophilic Esophagitis for Adults and Children: A Network Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Multiple pharmacological interventions have been studied for managing eosinophilic esophagitis (EoE). We performed a comprehensive systematic review and network meta-analysis of all available randomized controlled trials (RCT) to assess the efficacy and safety of these interventions in EoE in adults and children.

METHODS

We performed a comprehensive review of Embase, PubMed, MEDLINE OVID, Cochrane CENTRAL, and Web of Science through May 10, 2023. We performed frequentist approach network meta-analysis using random effects model. We calculated the odds ratio (OR) with 95% CI for dichotomous outcomes.

RESULTS

Our search yielded 25 RCTs with 25 discrete interventions and 2067 patients. Compared with placebo, the following interventions improved histology (using study definitions) in decreasing order on ranking: orodispersible budesonide (ODB) low dose, ODB high dose, oral viscous budesonide (OVB) high dose, fluticasone tablet 1.5 mg twice daily, fluticasone 3 mg twice daily, esomeprazole, dupilumab every 2 weeks, dupilumab weekly, OVB medium dose, fluticasone 3 mg daily, cendakimab 180 mg, prednisone, swallowed fluticasone, fluticasone tablet 1.5 mg daily, OVB low dose, reslizumab 3 mg/kg, reslizumab 1 mg/kg, and reslizumab 2 mg/kg.

CONCLUSIONS

Network meta-analysis demonstrates histological efficacy of multiple medications for EoE. Because of the heterogeneity and large effect size, we recommend more trials comparing pharmacotherapeutic interventions with each other and placebo. An important limitation of this study is absence of clinical efficacy data due to insufficient data. Other limitations include heterogeneity of operator, population, and outcome analysis.

Allergic Airway Inflammation Emerges from Gut Inflammation and Leakage in Mouse Model of Asthma

Asthma is an allergic airway inflammatory disease characterized by type 2 immune responses. Growing evidence suggests an association between allergic airways and intestinal diseases. However, the primary site of disease origin and initial mechanisms involved in the development of allergic airway inflammation (AAI) is not yet understood. Therefore, the initial contributing organs and mechanisms involved in the development of AAI are investigated using a mouse model of asthma. This study, without a local allergen challenge into the lungs, demonstrates a significant increase in intestinal inflammation with signature type-2 mediators including IL-4, IL-13, STAT6, eosinophils, and Th2 cells. In addition, gut leakage and mRNA expressions of gut leakage markers significantly increase in the intestine. Moreover, reduced mRNA expressions of tight junction proteins are observed in gut and interestingly, in lung tissues. Furthermore, in lung tissues, an increased pulmonary barrier permeability and IL-4 and IL-13 levels associated with significant increase of lipopolysaccharide-binding protein (LBP-gut leakage marker) and eosinophils are observed. However, with local allergen challenges into the lungs, these mechanisms are further enhanced in both gut and lungs. In conclusion, the primary gut originated inflammatory responses translocates into the lungs to orchestrate AAI in a mouse model of asthma.

A Practical Update on Pediatric Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an emerging atopic disease of unknown etiology limited to the esophagus. The pathogenesis is still understood and is likely characterized by type 2 inflammation. Food allergens are the primary triggers of EoE that stimulate inflammatory cells through an impaired esophageal barrier. In children and adolescents, clinical presentation varies with age and mainly includes food refusal, recurrent vomiting, failure to thrive, abdominal/epigastric pain, dysphagia, and food impaction. Upper-gastrointestinal endoscopy is the gold standard for diagnosing and monitoring EoE. EoE therapy aims to achieve clinical, endoscopic, and histological ("deep") remission; prevent esophageal fibrosis; and improve quality of life. In pediatrics, the cornerstones of therapy are proton pump inhibitors, topical steroids (swallowed fluticasone and viscous budesonide), and food elimination diets. In recent years, much progress has been made in understanding EoE pathogenesis, characterizing the clinical and molecular heterogeneity, and identifying new therapeutic approaches. Notably, clinical, molecular, endoscopic, and histological features reflect and influence the evolution of inflammation over time and the response to currently available treatments. Therefore, different EoE phenotypes and endotypes have recently been recognized. Dupilumab recently was approved by FDA and EMA as the first biological therapy for adolescents (≥12 years) and adults with active EoE, but other biologics are still under consideration. Due to its chronic course, EoE management requires long-term therapy, a multidisciplinary approach, and regular follow-ups.

When Supplemental Formula Is Essential: Overcoming Barriers to Hypoallergenic Formula Access for Patients With Food Allergies

For food-allergic patients, hypoallergenic formulas (HFs) are medically indicated, often a primary component of the diet and essential for patient safety, health, nutrition, and overall well-being. Yet, food allergy is not included among the conditions mandated for coverage under federal health programs and private health insurance. The 2022 infant formula crisis has affected many North American families and has particularly influenced patients with food allergies who rely on a limited number of safe HF brands to safely meet their nutritional needs for growth and development. The current formula shortage further highlights the longstanding difficulties faced by families with food allergies in accessing HF. Within this context, this article focuses on chronic barriers faced by patients with food allergies in accessing HF and proposes potential solutions. Legislation is desperately needed to address HF affordability through changes in insurance reimbursement and disparities in access to HF among individuals with food allergy.

A different starting line for allergic march: food protein-induced allergic proctocolitis

OBJECTIVE

The aim of this study is to investigate the long-term prognosis of food protein--induced allergic proctocolitis (FPIAP) patients, the risk of developing both allergic and gastrointestinal diseases, and to evaluate whether it leads to allergic march.

METHODS

A total of 149 children who were diagnosed with FPIAP and developed tolerance at least 5 years prior to the study and 41 children (with no history of food allergy) as a control group were enrolled. Both groups were re-evaluated for allergic diseases as well as gastrointestinal disorders.

RESULTS

The mean age of diagnosis for the FPIAP group was 4.2 ± 3.0 months, while the mean age of tolerance was 13.9 ± 7.7 months. The mean age of both FPIAP and control groups at the last visit was 101.6 ± 24.4 and 96.3 ± 24.1 months, respectively (P = 0.213). At the final evaluation of both groups, the comorbid allergic disease was significantly higher in the FPIAP group (P < 0.001). There was no significant difference between the two groups in terms of functional gastrointestinal disorders (FGIDs), eosinophilic gastrointestinal diseases, and inflammatory bowel disease (P = 0.198, 0.579, and 0.579, respectively).In the FPIAP group, the allergic disease was significantly higher at the final visit in patients with comorbid allergic disease at diagnosis (P < 0.001). In the FPIAP group, FGID was significantly higher in the group that developed allergic diseases in the future, compared to the group that did not develop allergic diseases in the future (P = 0.034). The proportion of both FGID and allergic diseases was significantly higher in subjects that developed tolerance at >18 months, compared to subjects that developed tolerance at >18 months (P < 0.001 and <0.001, respectively).

CONCLUSIONS

Patients with FPIAP may develop allergic diseases as well as FGID in the long term.

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.

Dietary Strategies in Adult Patients with Eosinophilic Esophagitis: A State-of-the-Art Review

Allergen-free diets are a specific and effective anti-inflammatory therapy for eosinophilic esophagitis. They should be carried out by a multidisciplinary team to reduce side effects and improve adherence. According to recent guidelines and expert opinions, empirical diets with a reduced number of eliminated food categories and a step-up approach are the most encouraged strategy to reduce the number of endoscopies to identify food trigger(s) and maximize clinical results and adherence. Despite the fact that allergy testing-based diets are not recommended at a population level, geographical sensitization patterns may play a role in some patients in specific areas, such as in Southern and Central Europe.

The Role of Benralizumab in Eosinophilic Immune Dysfunctions: A Case Report-Based Literature Review

In the past years, the knowledge of eosinophils playing a primary pathophysiologic role in several associated conditions has led to the development of biologics targeting therapies aiming at normalizing the immune response, reducing chronic inflammation, and preventing tissue damage. To better illustrate the potential relationship between different eosinophilic immune dysfunctions and the effects of biological therapies in this scenario, here, we present a case of a 63-year-old male first referred to our department in 2018 with a diagnosis of asthma, polyposis, and rhinosinusitis and presenting a suspicion of nonsteroidal anti-inflammatory drugs' allergy. He also had a past medical history of eosinophilic gastroenteritis/duodenitis (eosinophilia counts >50 cells/high-power field HPF). The use of multiple courses of corticosteroid therapy failed to completely control these conditions. In October 2019, after starting benralizumab (an antibody directed against the alpha chain of the IL-5 cytokine receptor) as add-on treatment for severe eosinophilic asthma, important clinical improvements were reported both on the respiratory (no asthma exacerbations) and gastrointestinal systems (eosinophilia count 0 cells/HPF). Patients' quality of life also increased. Since June 2020, systemic corticosteroid therapy was reduced without worsening of gastrointestinal symptoms or eosinophilic inflammation. This case warns of the importance of early recognition and appropriate individualized treatment of eosinophilic immune dysfunctions and suggests the conduction of further larger studies on the use of benralizumab in gastrointestinal syndromes aiming at better understanding its relying mechanisms of action in the intestinal mucosa.

Eosinophilic Gastrointestinal Diseases in Inborn Errors of Immunity

Inborn errors of immunity (IEI) are disorders mostly caused by mutations in genes involved in host defense and immune regulation. Different degrees of gastrointestinal (GI) involvement have been described in IEI, and for some IEI the GI manifestations represent the main and characteristic clinical feature. IEI also carry an increased risk for atopic manifestations. Eosinophilic gastrointestinal diseases (EGIDs) are emerging disorders characterized by a chronic/remittent and prevalent eosinophilic inflammation affecting the GI tract from the esophagus to the anus in the absence of secondary causes of intestinal eosinophilia. Data from the U.S. Immunodeficiency Network (USIDNET) reported that EGIDs are more commonly found in patients with IEI. Considering this element, it is reasonable to highlight the importance of an accurate differential diagnosis in patients with IEI associated with mucosal eosinophilia to avoid potential misdiagnosis. For this reason, we provide a potential algorithm to suspect an EGID in patients with IEI or an IEI in individuals with a diagnosis of primary EGID. The early diagnosis and detection of suspicious symptoms of both conditions are fundamental to prevent clinically relevant complications.

"Tickle me pink": update in eosinophilic gastrointestinal disorders

PURPOSE OF REVIEW

Eosinophilic gastrointestinal diseases (EGIDs) outside of the esophagus have been previously enigmatic and rare diagnoses. Fortunately, increasing research over the past few decades has led to an improved understanding of disease pathophysiology and epidemiology. This has been foundational for developing accurate nomenclature, diagnostic criteria, and therapeutics.

RECENT FINDINGS

This article will review recent updates in nonesophageal EGIDs. Accurate disease classification and nomenclature developed from international consensus are now available, as well as data challenging the notion that abnormal endoscopic findings are rare in this population. Studies on natural history, outcomes, and impact on patient quality of life are reviewed. Lastly, retrospective studies and clinical trials on EGID therapies are summarized.

SUMMARY

With a standardized nomenclature system for EGIDs now established, formal diagnostic guidelines and criteria for nonesophageal EGIDs are in active development. While management remains challenging compared with eosinophilic esophagitis, research and development of effective, steroid-sparing therapies (primarily through biologics and dietary therapy) remain underway. In eosinophilic colitis, the rarest EGID, research remains focused on illuminating pathophysiology. Ongoing research will continue to improve understanding of natural history, outcomes, and therapeutic options for these diseases.