Eosinophilic oesophagitis endotype classification by molecular, clinical, and histopathological analyses: a cross-sectional study

Future of therapy and monitoring for eosinophilic esophagitis and eosinophilic gastrointestinal diseases

Eosinophilic gastrointestinal disorders, including eosinophilic esophagitis, are chronic TH2-mediated diseases. Establishing a diagnosis and initiating treatment are crucial to limit disease progression that may lead to tissue remodeling and the development of strictures that significantly affect patients' quality of life. Expert consensus guidelines provide a framework for treating eosinophilic esophagitis with diet elimination, proton pump inhibitors, swallowed topical steroids, or dupilumab, and for monitoring with sedated endoscopy for gross and histologic evaluation. Although this provides an established algorithm for treating and monitoring eosinophilic esophagitis, there is less established research for the rarer eosinophilic gastrointestinal disorders (eosinophilic gastritis, enteritis, and colitis). Research advancements continue rapidly to emerge, identifying potential biomarkers, therapeutic targets, and monitoring strategies. In this article, we review the currently accepted methods for treating and monitoring eosinophilic gastrointestinal disorders with a focus on eosinophilic esophagitis, assess methods currently under investigation, and provide an aspirational vision for future disease management with a streamlined algorithm of personalized medicine and less invasive monitoring.

The Modulation of Cell Plasticity by Budesonide: Beyond the Metabolic and Anti-Inflammatory Actions of Glucocorticoids

The synthetic cortisol analog budesonide (BUD) is an essential drug employed to manage chronic inflammatory diseases in humans, mainly those involving gastroenteric and airway mucosa, such as rhinitis, laryngitis, bronchitis, esophagitis, gastritis, and colitis, with high levels of success. As a glucocorticoid, BUD prevents the expression of pro-inflammatory cytokines/chemokines and the recruitment of immune cells into the inflamed mucosa. However, emerging evidence indicates that BUD, unlike classical glucocorticoids, is also a potent modulator of stem and cancer cell behavior/plasticity. Certainly, BUD stabilizes cell-cell adhesions, preventing embryonic stem cell differentiation and inhibiting the development of 3D gastruloids. In addition, BUD inhibits the motile/invasive propensity of different cancer cells, including breast, lung, and pancreatic cancer. Finally, it prevents the infection of positive single-stranded human-infecting RNA viruses such as SARS-CoV-2. At a molecular level, BUD induces epigenetic changes and modifies the transcriptome of epithelial, stem, and cancer cells, providing molecular support to the immune cell-independent activity of BUD. Here, we performed an in-depth review of these unexpected activities of BUD, identified by unbiased drug screening programs, and we emphasize the molecular mechanisms modulated by this efficacious drug that deserve further research.

Interleukin-13-mediated alterations in esophageal epithelial mitochondria contribute to tissue remodeling in eosinophilic esophagitis

Background

The significance of mitochondria in EoE pathobiology remains elusive.

Objective

To determine the impact of EoE inflammatory mediators upon mitochondrial biology in esophageal epithelium, the mechanisms mediating these effects, and their functional significance to EoE pathobiology.

Methods

Mitochondria were evaluated in human biopsies, MC903/Ovalbumin-induced murine EoE, and human esophageal keratinocytes. Esophageal keratinocytes were treated with EoE-relevant cytokines and JAK/STAT inhibitor ruxolitinib. To deplete mitochondria, 3D organoids generated from TFAM loxp/loxp mice were subjected ex vivo to Cre or siRNA against Transcription factor A, mitochondria (TFAM) was transfected into esophageal keratinocytes. Mitochondrial respiration, membrane potential, and superoxide levels were measured.

Results

We find evidence of increased mitochondria in esophageal epithelium of patients with EoE and mice with EoE-like inflammation. In esophageal keratinocytes, IL-4 and IL-13 increase mitochondrial mass. IL-13 increases mitochondrial biogenesis in a JAK/STAT-dependent manner. In 3D organoids, IL-13 limits squamous cell differentiation (SCD), and this is blunted upon TFAM depletion. IL-13 decreases mitochondrial respiration and superoxide level, although mitochondria remain intact. IL-13-mediated suppression of superoxide was abrogated upon TFAM depletion in esophageal keratinocytes.

Conclusions

We report that increased mitochondrial mass is a feature of EoE. Among EoE-relevant cytokines, IL-13 is the primary driver of increased mitochondrial mass in esophageal keratinocytes by promoting mitochondrial biogenesis in a JAK/STAT-dependent manner. IL-13-mediated accumulation of mitochondria impairs SCD in esophageal keratinocytes and also suppresses oxidative stress, a factor that is known to induce SCD. These findings identify a novel mechanism through which IL-13 promotes EoE-associated epithelial remodeling.

Clinical Implication

These findings further lay a foundation for exploration of level of esophageal epithelial mitochondria as a predictive biomarker for response to dupilumab.

Capsule summary

IL-13 promotes mitochondrial biogenesis in esophageal epithelium, contributing to impaired squamous cell differentiation.

Eosinophilic oesophagitis in adults: from symptoms to therapeutic options

Eosinophilic oesophagitis (EoE) is a chronic and progressive immune-mediated condition, typically affecting young atopic male adults and potentially leads to organ dysfunction and fibrosis. The clinical spectrum widely varies -from non-troublesome dysphagia to food impaction- and hence the rate of misdiagnosis and diagnostic delay are high, especially when presenting with minor symptoms, such as heartburn and acid regurgitation. There have been several major therapeutic breakthroughs for the management of EoE in recent years. Highly effective conventional agents with oesophagus-specific formulations (i.e. orodispersible budesonide) and a biological agent (i.e. dupilumab) now have a formal indication. Oesophageal dilation may be indicated in case of strictures, which are more common in longstanding and untreated disease. Therefore, the early diagnosis of this disorder and specialist referral is if of great importance. The evaluation of alarm signs and typical presentation patterns should allow a more straightforward recognition. The emergency and internal medicine doctors should actively be involved in this process and take part to the multidisciplinary care of patients with EoE, to allow better patient care and clinical outcomes.

Insights into the natural history and disease course of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated disease marked by eosinophilic inflammation and esophageal dysfunction, with a significant impact on morbidity, quality of life, and health care utilization. Once considered rare, EoE has become increasingly prevalent, with global estimates exceeding 140 cases per 100,000 individuals. This rise highlights the need to better understand the natural history and disease course to inform diagnosis and management strategies. Evidence suggests that EoE is a progressive condition, such that untreated inflammation contributes to esophageal remodeling and fibrotic complications over years to decades. Patients can develop esophageal food impactions, leading to emergency department utilization and the need for emergent endoscopy. In addition, patients with fibrostenotic disease can require serial dilations. Long-term management, including dietary therapy, proton pump inhibitors, topical corticosteroids, and newer therapies such as dupilumab, demonstrate promise in altering the disease course. However, variability exists in the strength of evidence regarding each therapy's ability to halt or reverse fibrosis. Knowledge gaps persist, particularly in defining fibrosis, identifying phenotypes prone to progression, and tailoring therapies to individual patients. Addressing these gaps will require continued research into understanding fibrosis progression and how therapies alter this trajectory. These efforts are poised to significantly improve clinical care and enhance outcomes for patients with EoE.

Worsening Disease Severity as Measured by I-SEE Associates With Decreased Treatment Response to Topical Steroids in Eosinophilic Esophagitis Patients

BACKGROUND & AIMS

The Index of Severity for Eosinophilic Esophagitis (I-SEE) grades eosinophilic esophagitis (EoE) severity across several domains. We assessed associations between EoE features and severity by I-SEE at diagnosis, and baseline I-SEE and outcomes following topical corticosteroids (tCS).

METHODS

We conducted a retrospective cohort study of newly diagnosed EoE patients. Data were extracted to complete the I-SEE at diagnosis. Disease activity was categorized as mild (I-SEE 1-6), moderate (I-SEE 7-14), or severe (I-SEE ≥15). We compared baseline characteristics by I-SEE category. We assessed if baseline I-SEE associated with treatment response in patients treated with tCS.

RESULTS

Of 1312 patients, there were 657 (50%), 461 (35%), and 194 (15%) with mild, moderate, and severe disease by I-SEE, respectively. Baseline scores were similar for children (8.5 ± 6.6) and adults (8.8 ± 6.5) (P = .37). Compared with mild or moderate disease, patients with severe disease were younger (23.8 ± 19.8 years for severe vs 28.0 ± 19.7 years for mild vs 30.3 ± 17.0 years for moderate; P < .001), had lower body mass index (21.6 ± 7.1 kg/m2 vs 24.4 ± 7.0 kg/m2 vs 25.7 ± 6.8 kg/m2; P < .001), and had longer symptom length preceding diagnosis (9.3 ± 10.5 years vs 5.9 ± 7.5 years vs 7.2 ± 7.9 years; P < .001). The baseline category associated with tCS response, with severe patients less likely to have histologic response (49% vs 55% vs 64%; P = .03 for <15 eosinophils per high-power field) and symptomatic responses, while also having the highest post-treatment eosinophilic esophagitis endoscopic reference scores.

CONCLUSIONS

I-SEE correlated with baseline features in a large EoE cohort, performed similarly in children and adults, and associated with post-treatment responses to tCS. These data support that I-SEE provides prognostic data and suggest that severe disease may benefit from intensive upfront management.

Exploring the Link Between Atopic Dermatitis and Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) and atopic dermatitis (AD) are two known and sometimes comorbid type 2 helper cell-mediated diseases. EoE shares clinical features, immunologic pathways, susceptibility loci, and risk with atopic conditions including food allergies (food allergies), asthma, allergic rhinitis (AR), and AD. These conditions share an impaired immunological response against a range of antigens or allergens, leading to CD4+ Th2 differentiation and overproduction of immunoglobulin E (IgE). The emerging coexistence of EoE and AD presents a compelling area of study. Both diseases manifest on stratified squamous epithelium along the skin-gut continuum and have overlapping treatment algorithms that include avoidance of triggers, topical steroids, and dupilumab. This narrative review highlights the clinical and immunologic nuances underlying these two conditions and sheds light on potential new research and therapeutic avenues.

Distinct roles for thymic stromal lymphopoietin (TSLP) and IL-33 in experimental eosinophilic esophagitis

Rationale

Thymic stromal lymphopoietin (TSLP) and IL-33 are alarmins implicated in EoE pathogenesis by activating multiple cells including mast cells (MCs). Whether TSLP or IL-33 have a role in EoE and whether their activities are distinct requires further investigation.

Methods

Experimental EoE was induced in wild type (WT) Il33 -/- and Crlf2 -/- mice. TSLP or IL-5 were neutralized using antibodies. Esophageal histopathology was determined by H&E, anti-Ki67, anti-CD31 and anti-MBP staining. Esophageal RNA was subjected to RNA sequencing. Bone marrow-derived MCs were activated with TSLP and IL-13 was determined (ELISA).

Results

TSLP and IL-33 were overexpressed in human and experimental EoE. Human and mouse esophageal MCs displayed the highest level of Crlf2 (TSLPR) compared to other immune cells. Crlf2 -/- mice were nearly-completely protected from EoE, and TSLP neutralization resulted in decreased basal cell proliferation, eosinophilia, lamina propria thickening and vascularization. Induction of experimental EoE in Il33 -/- mice resulted in reduced eosinophilia but no alterations in tissue remodeling were observed compared to WT mice. RNA sequencing revealed that TSLP regulates the expression of key genes associated with human EoE (e.g. eotaxins, Il19, Klk5, Flg, Il36rn, Il1r2) and suggest a role for TSLP in regulating IL-1 signaling, barrier integrity and epithelial cell differentiation. Experimental EoE was characterized by a MC-associated gene signature and elevated MCs. Activation of MCs with TSLP resulted in secretion of IL-13.

Conclusion

TSLP and IL-33 have non-redundant functions in experimental EoE. This study highlights TSLP as an upstream regulator of IL-13 and a potential therapeutic target for EoE.

CSF1-dependent macrophage support matrisome and epithelial stress-induced keratin remodeling in Eosinophilic esophagitis

Atopic diseases such as Eosinophilic Esophagitis (EoE) often progress into fibrosis (FS-EoE), compromising organ function with limited targeted treatment options. Mechanistic understanding of FS-EoE progression is confounded by the lack of preclinical models and the heavy focus of research on eosinophils themselves. We found that macrophage accumulation precedes esophageal fibrosis in FS-EoE patients. We developed a FS-EoE model via chronic administration of oxazalone allergen, in a transgenic mouse over-expressing esophageal epithelial hIL-5 (L2-IL5OXA). These mice display striking histopathologic features congruent with that found in FS-EoE patients. Unbiased proteomic analysis, using a unique extracellular-matrix (ECM) focused technique, identified an inflammation-reactive provisional basal lamina membrane signature and this was validated in two independent EoE patient RNA-sequencing/proteomic cohorts, supporting model significance. A wound healing signature was also observed involving hemostasis-associated molecules previously unnoted in EoE. We further identified the ECM glycoprotein, Tenascin-C (TNC), and the stress-responsive keratin-16 (KRT16) as IL-4 and IL-13 responsive mediators, acting as biomarkers of FS-EoE. To mechanistically address how the immune infiltrate shapes FS-EoE progression, we phenotyped the major immune cell subsets that coalesce with fibrosis in both the L2-IL5OXA mice and in FS-EoE patients. We found that macrophage are required for matrisome and cytoskeletal remodeling. Importantly, we show that macrophage accumulation precedes esophageal fibrosis and provide a novel therapeutic target in FS-EoE as their depletion with anti-CSF1 attenuated reactive matrisome and cytoskeletal changes. Thus, macrophage-based treatments and the exploration of TNC and KRT16 as biomarkers may provide novel therapeutic options for patients with fibrostenosis.

Diagnosing eosinophilic esophagitis in pediatric patients

INTRODUCTION

Eosinophilic esophagitis (EoE) is an increasingly common disease that can present in children with the symptoms of feeding dysfunction, abdominal pain, vomiting, reflux-like symptoms, dysphagia, or food impaction. Diagnostically, children must have symptoms, dense esophageal eosinophilia, and other potential causes of these findings ruled out. Diagnostic recognition is critical to avoid food impactions and potential esophageal stricture development.

AREAS COVERED

In this review, a PubMed search using the search terms eosinophilic esophagitis, pediatric, and diagnosis were used to cover the last 10 years (2013-2023) of literature.

EXPERT OPINION

Early detection of EoE in children depends on increased recognition of diagnostic clues by many specialties. As increasing efforts to publicize the importance of EoE in children continues, our understanding of the molecular underpinnings of EoE is making rapid advances. Increasing growth of this knowledge base will provide more personalized diagnostic approaches, targeted interventions, and innovative treatments.

Treatment Preference Archetypes in Eosinophilic Esophagitis and Their Implications for Therapy

INTRODUCTION

Little is known about how patients make decisions about and prioritize therapies and disease management in eosinophilic esophagitis (EoE). We aimed to systematically identify and characterize patient perspectives and attitudes that influence decision making for EoE management.

METHODS

To understand the diverse attitudes and values of patients with EoE, we designed a study using the Q-method. We iteratively developed 31 statements related to EoE disease management. Participants sorted statements by ranking from +4 (most agree) to -4 (most disagree). By-person factor analysis, using 2-factor and 3-factor rotation, revealed distinct preference archetypes.

RESULTS

Thirty-four adults with EoE (mean age 40.9 years, 51.4% male, 82.9% White) were recruited from gastroenterology and allergy clinics from a single center. We identified 2 treatment-centered archetypes: Medication preference, driven by symptoms and the desire to minimize risk of complications and Natural treatment preference , focusing on identifying trigger foods and diet adherence. Three-factor analysis revealed an additional archetype: Treatment ambivalent, a view of EoE as a mild and episodic (not chronic) disease with low priority to treat. Comparison by factor revealed 54% of those in the natural preference archetype were recategorized as treatment ambivalent , suggesting that they see natural treatment as a less complicated or milder strategy and may be at risk of nonadherence and reduced treatment uptake.

DISCUSSION

We identified 3 distinct treatment preference archetypes among individuals with EoE, underscoring the need for personalized treatment strategies, especially for those favoring natural approaches but masking ambivalence, and may be at risk of nonadherence or loss to follow-up.

Understanding tissue injury and remodelling in eosinophilic oesophagitis: development towards personalised medicine

Eosinophilic oesophagitis (EoE) is a chronic, immune-mediated condition characterised by eosinophilic infiltration of the oesophagus, leading to significant morbidity due to oesophageal dysfunction. The pathogenic course of EoE begins with tissue injury, marked by the intricate interplay of oesophageal barrier dysfunction and T helper 2-mediated inflammation. In response to tissue damage, a subsequent phase of tissue remodelling features a complex interaction between epithelial cells and stromal cells, aimed at tissue repair. The persistence of inflammation drives these mechanisms towards oesophageal fibrostenosis, mainly through the transforming growth factor-dependent, myofibroblast-driven accumulation of the extracellular matrix. Currently, treatment options for EoE are limited, with dietary intervention, proton pump inhibitors and oral steroids serving as first-line therapies. Dupilumab, an antiinterleukin (IL) 4/IL-13 agent, is the only biologic that has been approved by European and American regulatory authorities. However, emerging OMIC technologies significantly advance our understanding of EoE pathogenesis, revealing novel cellular and molecular mechanisms driving the disease. This progress has accelerated the identification of new therapeutic targets and agents, some already under clinical investigation, potentially expanding our therapeutic arsenal and paving the way for more personalised approaches. In this evolving landscape, artificial intelligence (AI) has shown great potential to further elaborate on the complexities of EoE heterogeneity, offering standardised tools for diagnosis, disease phenotyping, and prediction of treatment response. Though still in their early stages, integrating OMICs and AI marks a pivotal step towards precision medicine in EoE.

Nonepithelial Gene Expression Correlates With Symptom Severity in Adults With Eosinophilic Esophagitis

BACKGROUND

The mechanistic basis of the variable symptomatology seen in eosinophilic esophagitis (EoE) remains poorly understood.

OBJECTIVE

We examined the correlation of a validated, patient-reported outcome metric with a broad spectrum of esophageal transcripts to uncover potential symptom pathogenesis.

METHODS

We extracted data from 146 adults with EoE through the Consortium of Eosinophilic Gastrointestinal Disease Researchers. Patients were subgrouped by esophageal dilation history. We compared a validated patient-reported outcome metric, the EoE Activity Index (EEsAI), with a set of transcripts expressed in the esophagus of patients with EoE, the EoE Diagnostic Panel (EDP). We used single-cell RNA sequencing data to identify the cellular source of EEsAI-related EDP genes and further analyzed patients with mild and severe symptoms.

RESULTS

The EEsAI correlated with the EDP total score, especially in patients without recent esophageal dilation (r = -0.31; P = .003). We identified 14 EDP genes that correlated with EEsAI scores (r ≥ 0.3; P < .05). Of these, 11 were expressed in nonepithelial cells and three in epithelial cells. During histologic remission, only four of 11 nonepithelial genes (36%) versus all three epithelial genes (100%) had decreased expression to less than 50% of that in active EoE. Fibroblasts expressed five of 11 nonepithelial EEsAI-associated EDP genes (45%). A subset of nonepithelial genes (eight of 11; 73%), but not EoE-representative genes (none of four; 0%; CCL26, CAPN14, DSG1, and SPINK7), was upregulated in patients with EoE with the highest versus lowest symptom burden.

CONCLUSION

The correlation of symptoms and nonepithelial esophageal gene expression substantiates that nonepithelial cells (eg, fibroblasts) likely contribute to symptom severity.

Impact of Atopic Status on Clinical Presentation and Treatment Response in Pediatric Patients With Eosinophilic Esophagitis

BACKGROUND

Nearly 80% of patients with eosinophilic esophagitis (EoE) have coexisting atopic disease, yet a subset do not. It is unclear if this lack of atopy impacts presentation or response to therapy.

OBJECTIVES

To characterize the presentation and response to therapy in atopic versus nonatopic pediatric patients with EoE.

METHODS

A case-control study of patients with EoE aged 6 months to 18 years (between 2018 and 2021) was performed. Patients were eligible if they had allergy testing, assessment of atopic history, and at least 1 endoscopy after initiation of treatment. Patients were considered nonatopic if they had negative allergy testing and no history of significant atopy. Response to therapy was classified as complete (peak eosinophils [eos] <15/high power field [hpf]), partial (≥15 eos/hpf but at least a 50% reduction in peak eos), or nonresponse.

RESULTS

A total of 168 participants were enrolled. The majority were White (n = 141, 84%), male (n = 124, 74%), and non-Hispanic (n = 158, 95%). The mean age at diagnosis was 9.4 years (standard deviation: ±4.8 years). A total of 123 participants (73.2%) were atopic, and 45 (26.8%) were nonatopic. There was no significant difference between atopic and nonatopic for most demographics or presenting symptoms. Nonatopic participants were younger than atopic participants (8.14 vs 9.8 years, P = .046). Swallowed topical corticosteroids (STC) and food elimination diets (FED) were used at a similar rate. There were no differences in treatment response between atopic/nonatopic participants in regard to STC, FED, or STC+FED.

CONCLUSIONS

Atopic status does not significantly impact presentation or response to treatment in pediatric EoE, but a lack of atopy may be a risk for earlier onset of disease.

Real world treatment patterns in patients with eosinophilic esophagitis in Japan

The management of eosinophilic esophagitis (EoE) has not been completely established yet. There is a controversy over the universal maintenance therapy for EoE to prevent esophageal fibrostenotic complications. Using an employer-based insurance claim database from January 2005 to September 2022, we investigated the treatment patterns of EoE and the occurrence of esophageal complications. The treatment patterns were analyzed at a 6-month interval from the diagnosis of EoE. The time to treatment discontinuation of proton pump inhibitor (PPI)/potassium-competitive acid blocker (P-CAB) was evaluated by the Kaplan-Meier method. Of 15,200,895 individuals, 615 patients with EoE were ultimately analyzed with the median follow-up time from the index date of 700 days. PPI/P-CAB and swallowed topical steroids accounted for 80% and 4.6% of the initial therapy, respectively. PPI/P-CAB use rapidly decreased by 40% in the first 6 months and afterwards reinitiation was rarely seen. The median time to treatment discontinuation were 172 days (95% CI 147-206 days) for PPI/P-CAB. Only 1 EoE patient developed esophageal fibrostenotic complications after the diagnosis. With the low incidence of esophageal complications, the universal maintenance therapy may not be necessary for mild EoE patients often seen in Japan.

Eosinophil specialization is regulated by exposure to the esophageal epithelial microenvironment

Distinct subsets of eosinophils are reported in inflammatory and healthy tissues, yet the functions of uniquely specialized eosinophils and the signals that elicit them, particularly in eosinophilic esophagitis, are not well understood. Herein, we report an ex vivo system wherein freshly isolated human eosinophils were cocultured with esophageal epithelial cells and disease-relevant proinflammatory (IL-13) or profibrotic (TGF-β) cytokines. Compared with untreated cocultures, IL-13 increased expression of CD69 on eosinophils, whereas TGF-β increased expression of CD81, CD62L, and CD25. Eosinophils from IL-13-treated cocultures demonstrated increased secretion of GRO-α, IL-8, and macrophage colony-stimulating factor and also generated increased extracellular peroxidase activity following activation. Eosinophils from TGF-β-treated cocultures secreted increased IL-6 and exhibited increased chemotactic response to CCL11 compared with eosinophils from untreated or IL-13-treated coculture conditions. When eosinophils from TGF-β-treated cocultures were cultured with fibroblasts, they upregulated SERPINE1 expression and fibronectin secretion by fibroblasts compared with eosinophils that were cultured with granulocyte macrophage colony-stimulating factor alone. Translational studies revealed that CD62L was heterogeneously expressed by eosinophils in patient biopsy specimens. Our results demonstrate that disease-relevant proinflammatory and profibrotic signals present in the esophagus of patients with eosinophilic esophagitis cause distinct profiles of eosinophil activation and gene expression.

Advances in omics data for eosinophilic esophagitis: moving towards multi-omics analyses

Eosinophilic esophagitis (EoE) is a chronic, allergic inflammatory disease of the esophagus characterized by eosinophil accumulation and has a growing global prevalence. EoE significantly impairs quality of life and poses a substantial burden on healthcare resources. Currently, only two FDA-approved medications exist for EoE, highlighting the need for broader research into its management and prevention. Recent advancements in omics technologies, such as genomics, epigenetics, transcriptomics, proteomics, and others, offer new insights into the genetic and immunologic mechanisms underlying EoE. Genomic studies have identified genetic loci and mutations associated with EoE, revealing predispositions that vary by ancestry and indicating EoE's complex genetic basis. Epigenetic studies have uncovered changes in DNA methylation and chromatin structure that affect gene expression, influencing EoE pathology. Transcriptomic analyses have revealed a distinct gene expression profile in EoE, dominated by genes involved in activated type 2 immunity and epithelial barrier function. Proteomic approaches have furthered the understanding of EoE mechanisms, identifying potential new biomarkers and therapeutic targets. However, challenges in integrating diverse omics data persist, largely due to their complexity and the need for advanced computational methods. Machine learning is emerging as a valuable tool for analyzing extensive and intricate datasets, potentially revealing new aspects of EoE pathogenesis. The integration of multi-omics data through sophisticated computational approaches promises significant advancements in our understanding of EoE, improving diagnostics, and enhancing treatment effectiveness. This review synthesizes current omics research and explores future directions for comprehensively understanding the disease mechanisms in EoE.

Advances and ongoing challenges in eosinophilic gastrointestinal disorders presented at the CEGIR/TIGERs Symposium at the 2024 American Academy of Allergy, Asthma & Immunology meeting

The Consortium of Eosinophilic Gastrointestinal disease Researchers (CEGIR) and The International Gastrointestinal Eosinophil Researchers (TIGERs) organized a daylong symposium at the 2024 annual meeting of the American Academy of Allergy, Asthma & Immunology. The symposium featured new discoveries in basic and translational research as well as debates on the mechanisms and management of eosinophilic gastrointestinal diseases. Updates on recent clinical trials and consensus guidelines were also presented. We summarize the updates on eosinophilic gastrointestinal diseases presented at the symposium.

Insights into the clinical, immunologic, and genetic underpinnings of food allergy

The last few decades have seen striking changes in the field of food allergy. The prevalence of the disease has risen dramatically in many parts of the globe, and management of the condition has undergone major revision. While delayed introduction of common allergenic foods during infancy was advised for many years, the learning early about peanut allergy (LEAP) trial and other studies led to a major shift in infant feeding practices, with deliberate early introduction of these foods now recommended. Additionally, the Food and Drug Administration approved the first treatment for food allergy in 2020-a peanut oral immunotherapy (OIT) product that likely represents just the beginning of new immunotherapy-based and other treatments for food allergy. Our knowledge of the environmental and genetic factors contributing to the pathogenesis of food allergy has also undergone transformational advances. Here, we will discuss our efforts to improve the clinical care of patients with food allergy and our understanding of the immunological mechanisms contributing to this common disease.

Losartan Treatment Reduces Esophageal Eosinophilic Inflammation in a Subset of Eosinophilic Esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic, food antigen-driven esophageal disorder. Connective tissue disorders (CTDs) and esophageal connective tissue alterations are associated with EoE. Therefore, angiotensin II type 1 receptor blockade with losartan, an accepted CTD treatment, is a potential EoE treatment.

OBJECTIVE

We evaluated losartan's effects on esophageal pathology, symptoms, and safety in patients with EoE with and without a CTD in an open-label, non-placebo controlled multisite study.

METHODS

Fifteen participants with EoE, aged 5 to 23 years, underwent treatment with per-protocol titrated doses of losartan in an open-label, 16-week pilot trial. Losartan was added to standard of care therapy and 14 patients completed the study. Eosinophil counts served as the primary end point, whereas we also assessed the EoE Histology Scoring System, Endoscopic Reference Scores, EoE Diagnostic Panel, and patient-reported outcomes.

RESULTS

Esophageal eosinophilia was not reduced after losartan. The peak eosinophil count was not reduced for the proximal (median [interquartile range]: -3 [-22 to 3]; P = .49) and distal esophagus (median [interquartile range]: -18 [-39 to -1]; P = .23). There were no differences in losartan response in EoE with or without CTD (n = 7 and 8, respectively). Regardless, in a small subset of four participants esophageal eosinophilia was resolved with a concomitant reduction in EoE Histology Scoring System score and Endoscopic Reference Score. Across all subjects, the Pediatric EoE Symptom Score, Pediatric Quality of Life Inventory EoE Module, and EoE Diagnostic Panel improved after losartan (P < .05).

CONCLUSIONS

Losartan treatment was associated with improved patient-reported outcome scores and EoE Diagnostic Panel biomarkers although without a reduction in esophageal eosinophilia overall. A subset of patients demonstrated improved histopathologic and endoscopic features that could not be tied to a specific feature predicting response to treatment.

Clinical and molecular correlates of the Index of Severity for Eosinophilic Esophagitis

BACKGROUND

The Index of Severity for Eosinophilic Esophagitis (I-SEE) is a new expert-defined clinical tool that classifies disease severity of eosinophilic esophagitis (EoE).

OBJECTIVE

We aimed to determine whether I-SEE is associated with patient characteristics, molecular features of EoE, or both.

METHODS

We analyzed a prospective cohort of patients with EoE from the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR). Associations between I-SEE and clinical and molecular features (assessed by an EoE diagnostic panel [EDP]) were assessed.

RESULTS

In 318 patients with chronic EoE (209 adults, 109 children), median total I-SEE score was 7.0, with a higher symptoms and complications score in children than adults (4.0 vs 1.0; P < .001) and higher inflammatory and fibrostenotic features scores in adults than children (3.0 vs 1.0 and 3.0 vs 0, respectively; both P < .001). Total I-SEE score had a bimodal distribution with the inactive to moderate categories and severe category. EDP score correlated with total I-SEE score (r = -0.352, P < .001) and both inflammatory and fibrostenotic features scores (r = -0.665, P < .001; r = -0.446, P < .001, respectively), but not with symptoms and complications scores (r = 0.047, P = .408). Molecular severity increased from inactive to mild and moderate, but not severe, categories. Longitudinal changes of modified I-SEE scores and inflammatory and fibrostenotic features scores reflected histologic and molecular activity.

CONCLUSIONS

I-SEE score is associated with select clinical features across severity categories and with EoE molecular features for nonsevere categories, warranting further validation.

Diagnosis and management of eosinophilic esophagitis in children: An update from the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN)

INTRODUCTION

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus characterized by symptoms of esophageal dysfunction and histologically by predominantly eosinophilic infiltration of the squamous epithelium. European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) published a guideline in 2014; however, the rapid evolution of knowledge about pathophysiology, diagnostic criteria, and therapeutic options have made an update necessary.

METHODS

A consensus group of pediatric gastroenterologists from the ESPGHAN Working Group on Eosinophilic Gastrointestinal Diseases (ESPGHAN EGID WG) reviewed the recent literature and proposed statements and recommendations on 28 relevant questions about EoE. A comprehensive electronic literature search was performed in MEDLINE, EMBASE, and Cochrane databases from 2014 to 2022. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess the quality of evidence and formulate recommendations.

RESULTS

A total of 52 statements based on the available evidence and 44 consensus-based recommendations are available. A revision of the diagnostic protocol, options for initial drug treatment, and the new concept of simplified empiric elimination diets are now available. Biologics are becoming a part of the potential armamentarium for refractory EoE, and systemic steroids may be considered as the initial treatment for esophageal strictures before esophageal dilation. The importance and assessment of quality of life and a planned transition to adult medical care are new areas addressed in this guideline.

CONCLUSION

Research in recent years has led to a better understanding of childhood EoE. This guideline incorporates the new findings and provides a practical guide for clinicians treating children diagnosed with EoE.

Animal models of eosinophilic esophagitis

Eosinophilic esophagitis is a chronic inflammatory disorder of the esophagus. Over the past 25 yr, great strides have been made toward understanding its pathogenesis, in part due to studies in several types of animal models. The vast majority of these models have been characterized in mice. In this review, we summarize the histopathological features of eosinophilic esophagitis recapitulated by these animal models, as well as discuss their strengths and weaknesses.

Novel transcriptomic panel identifies histologically active eosinophilic oesophagitis

BACKGROUND AND AIMS

Eosinophilic oesophagitis (EoE) is characterised by symptoms of esophageal dysfunction and oesinophil tissue infiltration. The EoE Diagnostic Panel (EDP) can distinguish between active and non-active EoE using a set of 77 genes. Recently, the existence of distinct EoE variants featuring symptoms similar to EoE, such as oesophageal dysfunction but lacking eosinophil infiltration, had been determined.

METHODS

We used oesophageal biopsies from patients with histologically active (n=10) and non-active EoE (n=9) as well as from healthy oesophageal controls (n=5) participating in the Swiss Eosinophilic Esophagitis Cohort Study (SEECS) and analysed the gene expression profile in these biopsies by total RNA-sequencing (RNA-seq). Moreover, we employed the publicly accessible RNA-seq dataset (series GSE148381) as reported by Greuter et al, encompassing a comprehensive genomic profile of patients presenting with EoE variants.

RESULTS

A novel, diagnostic gene expression panel that can effectively distinguish patients with histologically active conventional EoE from patients with EoE in histological remission and control individuals, and from three newly discovered EoE variants was identified. Histologically Active EoE Diagnostic Panel (HAEDP) consists of 53 genes that were identified based on differential expression between histologically active EoE, histological remission and controls (p≤0.05). By combining the HAEDP with EDP, we expanded our knowledge about factors that may contribute to the inflammation in EoE and improved our understanding of the underlying mechanisms of the disease. Conversely, we suggested a compact group of genes common to both HAEDP and EDP to create a reliable diagnostic tool that might enhance the accuracy of EoE diagnosis.

CONCLUSION

We identified a novel set of 53 dysregulated genes that are closely associated with the histological inflammatory activity of EoE. In combination with EDP, our new panel might be a valuable tool for the accurate diagnosis of patients with EoE as well as for monitoring their disease course.

Triggers for eosinophilic esophagitis (EoE): The intersection of food allergy and EoE

Eosinophilic esophagitis and IgE-mediated food allergy are both food-triggered diseases that are increasing in prevalence. They share many clinical links, including significant comorbidity and similar food triggers, and as atopic diseases, they likely share upstream mechanisms related to barrier function and signals leading to TH2 skewing. In this review, we focus on links between eosinophilic esophagitis and IgE-mediated food allergy with an emphasis on what insights may be derived from overlapping food triggers and immune phenotypes. Through further investigation of these connections, we may be able to better understand not only IgE-mediated food allergy and eosinophilic esophagitis but also general atopic response to food proteins and evolution of allergic response to food.

Development and dysfunction of structural cells in eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a disorder characterized by dysfunction and chronic local inflammation of the esophagus. The incidence and prevalence of EoE are increasing worldwide. The mechanisms responsible are poorly understood, and effective treatment options are limited. From the lumen outward, the esophagus comprises stratified squamous epithelium, lamina propria, and muscle. The tissue-specific nature of EoE strongly suggests that structural cells in the esophagus are involved in the EoE diathesis. Epithelial basal cell hyperplasia and dilated intercellular spaces are cardinal features of EoE. Some patients with EoE develop lamina propria fibrosis, strictures, or esophageal muscle dysmotility. Clinical symptoms of EoE are only weakly correlated with peak eosinophil count, implying that other cell types contribute to EoE pathogenesis. Epithelial, endothelial, muscle, and fibroblast cells can each initiate inflammation and repair, regulate tissue resident immune cells, recruit peripheral leukocytes, and tailor adaptive immune cell responses. A better understanding of how structural cells maintain tissue homeostasis, respond to cell-intrinsic and cell-extrinsic stressors, and exacerbate and/or resolve inflammatory responses in the esophagus is needed. This knowledge will facilitate the development of more efficacious treatment strategies for EoE that can restore homeostasis of both hematopoietic and structural elements in the esophagus.

Diagnosis, management and therapeutic options for eosinophilic esophagitis

PURPOSE OF REVIEW

Eosinophilic esophagitis is a chronic and commonly evolving condition leading to relevant and potentially irreversible burden in terms of tissue damage and related functional impairment, thus significantly impacting on quality of life. The aim of the present review is to summarize the recent advances in terms of diagnostic work-up and pharmacological and nonpharmacological management of the disease, under the broader perspective of type 2 inflammation.

RECENT FINDINGS

Two major novelties have prompted an innovative approach to EoE. In terms of diagnosis, it has been proposed to dissect the disease heterogeneity in three endotypes, independent from tissue eosinophil number: EoEe1, characterized by normal appearing oesophagus; EoEe2, associated with type 2 inflammation and steroid-refractoriness; EoEe3, whose features include adult onset, a more fibro-stenotic aspect and loss of epithelial gene expression. Concerning treatment, two recently licensed drugs for EoE, oro-dispersible budesonide and dupilumab represent the first treatment options specifically developed for EoE and addressing EoE-related peculiar pathobiological features.

SUMMARY

In the era of precision medicine, managing EoE according to a phenotype-driven approach might be helpful in defining the best treatment options in the different disease forms or stages. In addition, exploring the coexistence or the previous occurrence of other type 2 conditions may suggest the opportunity to specifically target type 2 inflammation through biologic therapy. The complex EoE pathobiology combining inflammatory and functional features, both at organ and systemic level, requires a multidimensional approach relying on the strict integration of gastroenterologists and allergist-immunologists.

Histopathology of Eosinophilic Esophagitis

Microscopic examination of esophageal biopsies is essential to diagnose eosinophilic esophagitis (EoE). Eosinophil inflammation is the basis for the diagnosis, but additional abnormalities may contribute to persistent symptoms and epithelial barrier dysfunction. Both peak eosinophil count and assessments of additional features should be included in pre-therapy and post-therapy pathology reports. Pathologic abnormalities identified in esophageal biopsies of EoE are reversible in contrast to esophageal strictures.

Minimally Invasive Approaches to Diagnose and Monitor Eosinophilic GI Diseases

PURPOSE OF REVIEW

This review seeks to understand novel avenues for eosinophilic GI disease management. Biomarkers offer a unique and non-invasive approach to tracking EoE disease progression. While no biomarkers have definitively met the diagnostic criteria for eosinophilic GI diseases, some biomarkers have been shown to be associated with disease activity. Here, we examine the potential of recently studied biomarkers.

RECENT FINDINGS

Current research shows advancements in blood, luminal fluid, and breath testing. Particular areas of interest include mRNA analyses, protein fingerprinting, amplicon sequence variants (ASVs), T cells and IgE receptors, eosinophilic cationic proteins, cytokines, and nitric oxide exhalation. Preliminary results showed that mucosal biomarkers, directly captured from the esophagus, may reflect the best representation of biopsy-based results, in contrast to biomarkers obtained from indirect or peripheral (blood, breath) methods. However, this is based on limited clinical studies without sufficient numbers to evaluate true diagnostic accuracy. Large-scale randomized trials are needed to fully ascertain both the optimal sampling technique and the specific biomarkers that reflect diagnostic status of the disease.

Pathophysiology and Clinical Impact of Esophageal Remodeling and Fibrosis in Eosinophilic Esophagitis

Most of the major clinical signs and consequences of eosinophilic esophagitis seem to be related to tissue remodeling. Important data on remodeling activity in patients with eosinophilic esophagitis are provided by a range of current and new biologic markers and diagnostics. To completely clarify the possible advantages and restrictions of therapeutic approaches, clinical studies should take into consideration the existence and reversibility of esophageal remodeling. The degree of mucosal or submucosal disease activity may not be reflected by epithelial eosinophilic inflammation, which is used to define one criterion of disease activity".

An esophagus cell atlas reveals dynamic rewiring during active eosinophilic esophagitis and remission

Coordinated cell interactions within the esophagus maintain homeostasis, and disruption can lead to eosinophilic esophagitis (EoE), a chronic inflammatory disease with poorly understood pathogenesis. We profile 421,312 individual cells from the esophageal mucosa of 7 healthy and 15 EoE participants, revealing 60 cell subsets and functional alterations in cell states, compositions, and interactions that highlight previously unclear features of EoE. Active disease displays enrichment of ALOX15+ macrophages, PRDM16+ dendritic cells expressing the EoE risk gene ATP10A, and cycling mast cells, with concomitant reduction of TH17 cells. Ligand-receptor expression uncovers eosinophil recruitment programs, increased fibroblast interactions in disease, and IL-9+IL-4+IL-13+ TH2 and endothelial cells as potential mast cell interactors. Resolution of inflammation-associated signatures includes mast and CD4+ TRM cell contraction and cell type-specific downregulation of eosinophil chemoattractant, growth, and survival factors. These cellular alterations in EoE and remission advance our understanding of eosinophilic inflammation and opportunities for therapeutic intervention.

Proton-Pump Inhibitors in Eosinophilic Esophagitis: A Review Focused on the Role of Pharmacogenetics

Proton-pump inhibitors (PPIs) are the most administered first-line treatment for eosinophilic esophagitis (EoE). However, only around half of EoE patients respond histologically to a double dosage of PPI. In addition, 70% of responders maintain EoE in remission after tapering the PPI dose. In order to avoid endoscopy with biopsies-the only accurate method of assessing PPI response-efforts have been made to identify PPI responder patients. The clinical or endoscopic features and biomarkers evaluated so far, however, have not proven to be sufficient in predicting PPI response. Although new approaches based on omics technologies have uncovered promising biomarkers, the specialized and complex procedures required are difficult to implement in clinical settings. Alternatively, PPI pharmacogenetics based on identifying variations in CYP2C19 and STAT6 genes have shown promising results in EoE, and could easily be performed in most laboratories. Other genetic variations have also been associated with PPI response and may explain those cases not related to CYP2C19 or STAT6. Here, we provide an overview of PPI treatment in EoE and evidence of how genetic variations in CYP2C19 and other genes could affect PPI effectiveness, and also discuss studies evaluating the role of pharmacogenetics in predicting PPI response in patients with EoE.

Epithelial-Fibroblast Crosstalk in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an emerging form of food allergy that exerts a significant clinical and financial burden worldwide. EoE is clinically characterized by eosinophil-rich inflammatory infiltrates in esophageal mucosa and esophageal dysfunction. Remodeling events in esophageal epithelium and lamina propria also frequently occur in patients with EoE. Because subepithelial fibrosis is associated with esophageal stricture, the most severe consequence of EoE, there exists an urgent need for a deeper understanding of the molecular mechanisms mediating fibrosis in EoE. Here, we review emerging evidence from experimental model systems that implicates crosstalk between esophageal epithelial cells and underlying stromal cells in EoE fibrosis. We further discuss implications for epithelial-stromal interaction with regard to EoE patient care and propose future directions that may be pursued to further the understanding of epithelial-stromal crosstalk in EoE pathobiology.

Identification of CXC Chemokine Receptor 2 (CXCR2) as a Novel Eosinophils-Independent Diagnostic Biomarker of Pediatric Eosinophilic Esophagitis by Integrated Bioinformatic and Machine-Learning Analysis

Background

Eosinophilic esophagitis (EoE) is a complex allergic condition frequently accompanied by various atopic comorbidities in children, which significantly affects their life qualities. Therefore, this study aimed to evaluate pivotal molecular markers that may facilitate the diagnosis of EoE in pediatric patients.

Methods

Three available EoE-associated gene expression datasets in children: GSE184182, GSE 197702, GSE55794, along with GSE173895 were downloaded from the GEO database. Differentially expressed genes (DEGs) identified by "limma" were intersected with key module genes identified by weighted gene co-expression network analysis (WGCNA), and the shared genes went through functional enrichment analysis. The protein-protein interaction (PPI) network and the machine learning algorithms: least absolute shrinkage and selection operator (LASSO), random forest (RF), and XGBoost were used to reveal candidate diagnostic markers for EoE. The receiver operating characteristic (ROC) curve showed the efficacy of differential diagnosis of this marker, along with online databases predicting its molecular regulatory network. Finally, we performed gene set enrichment analysis (GSEA) and assessed immune cell infiltration of EoE/control samples by using the CIBERSORT algorithm. The correlations between the key diagnostic biomarker and immune cells were also investigated.

Results

The intersection of 936 DEGs and 1446 key module genes in EoE generated 567 genes, which were primarily enriched in immune regulation. Following the construction of the PPI network and filtration by machine learning, CXCR2 served as a potential diagnostic biomarker of pediatric EoE with a perfect diagnostic efficacy (AUC = ~1.00) in regional tissue/peripheral whole blood samples. Multiple infiltrated immune cells were observed to participate in disrupting the homeostasis of esophageal epithelium to varying degrees.

Conclusion

The immune-correlated CXCR2 gene was proved to be a promising diagnostic indicator for EoE, and dysregulated regulatory T cells (Tregs)/neutrophils might play a crucial role in the pathogenesis of EoE in children.

Clinical Features and Treatment Response to Topical Steroids in Ethnic and Racial Minority Patients With Eosinophilic Esophagitis

INTRODUCTION

Differences in eosinophilic esophagitis (EoE) presentation and outcomes by ethnicity or race remain understudied. We aimed to determine whether EoE patients of Hispanic/Latinx ethnicity or non-White race have differences in presentation at diagnosis or response to topical corticosteroid (tCS) treatment.

METHODS

This retrospective cohort study included subjects of any age with a new diagnosis of EoE and documentation of ethnicity or race. For those who had treatment with tCS and follow-up endoscopy/biopsy, we assessed histologic response (<15 eosinophils/hpf), global symptom response, and endoscopic response. Hispanic EoE patients were compared with non-Hispanics at baseline and before and after treatment. The same analyses were repeated for White vs non-Whites.

RESULTS

Of 1,026 EoE patients with ethnicity data, just 23 (2%) were Hispanic. Most clinical features at presentation were similar to non-Hispanic EoE patients but histologic response to tCS was numerically lower (38% vs 57%). Non-White EoE patients (13%) were younger at diagnosis and had less insurance, lower zip code-level income, shorter symptom duration, more vomiting, less dysphagia and food impaction, fewer typical endoscopic features, and less dilation. Of 475 patients with race data treated with tCS, non-Whites had a significantly lower histologic response rate (41% vs 59%; P = 0.01), and odds of histologic response remained lower after controlling for potential confounders (adjusted odds ratio 0.40, 95% confidence intervals: 0.19-0.87).

DISCUSSION

Few EoE patients at our center were Hispanic, and they had similar clinical presentations as non-Hispanics. The non-White EoE group was larger, and presentation was less dysphagia-specific. Non-White patients were also less than half as likely to respond to tCS.

Barriers to Timely Diagnosis of Eosinophilic Gastrointestinal Diseases

Although eosinophilic gastrointestinal diseases, including eosinophilic esophagitis, have been described over the past 2 to 3 decades, barriers to diagnosis and treatment are common and compounded by issues related to social determinants of health, race, ethnicity, and access to care. These barriers contribute to delays in diagnosis, resulting in persistent inflammation in the gastrointestinal tract, which can have significant consequences, including fibrostenotic complications in adults, failure to thrive in children, and decreased quality of life in all affected patients. In this commentary, we summarize gaps in knowledge regarding the epidemiology of eosinophilic gastrointestinal diseases, highlight barriers to diagnosis, discuss potential approaches based on best practices in other atopic and chronic gastrointestinal diseases, and provide recommendations for reducing barriers to timely diagnosis of eosinophilic gastrointestinal diseases in underserved populations.

Increasing Age at the Time of Diagnosis and Evolving Phenotypes of Eosinophilic Esophagitis Over 20 Years

BACKGROUND

The presentation of eosinophilic esophagitis (EoE) is heterogeneous, but trends over time are not known.

AIM

To determine whether clinical and endoscopic phenotypes at EoE diagnosis have changed over the past 2 decades.

METHODS

In this retrospective cohort study, adults and children with newly diagnosed EoE were phenotyped as follows: (1) inflammatory vs fibrostenotic vs mixed on endoscopy; (2) atopic vs non-atopic; (3) age at symptom onset; (4) age at diagnosis; (5) presence of autoimmune or connective tissue disease; and (6) responsive to steroids. The prevalence of different phenotypes was categorized by 5-year intervals. Multivariate analysis was performed to assess for changes in patient features over time.

RESULTS

Of 1187 EoE patients, age at diagnosis increased over time (from 22.0 years in 2002-2006 to 31.8 years in 2017-2021; p < 0.001) as did the frequency of dysphagia (67% to 92%; p < 0.001). Endoscopic phenotypes were increasingly mixed (26% vs 68%; p < 0.001) and an increasing proportion of patients had later onset of EoE. However, there were no significant trends for concomitant autoimmune/connective tissue disease or steroid responder phenotypes. On multivariate analysis, after accounting for age, dysphagia, and food impaction, the increase in the mixed endoscopic phenotype persisted (aOR 1.51 per each 5-year interval, 95% CI 1.31-1.73).

CONCLUSION

EoE phenotypes have changed over the past two decades, with increasing age at diagnosis and age at symptom onset. The mixed endoscopic phenotype also increased, even after controlling for age and symptomatology. Whether this reflects changes in provider recognition or disease pathophysiology is yet to be elucidated.

The New Therapeutic Frontiers in the Treatment of Eosinophilic Esophagitis: Biological Drugs

Eosinophilic esophagitis (EoE) is a multifaceted disease characterized by a wide heterogeneity of clinical manifestations, endoscopic and histopathologic patterns, and responsiveness to therapy. From the perspective of an effective approach to the patient, the different inflammatory mechanisms involved in the pathogenesis of EoE and biologics, in particular monoclonal antibodies (mAbs), targeting these pathways are needed. Currently, the most relevant is dupilumab, which interferes with both interleukin (IL)-4 and IL-13 pathways by binding IL-4 receptor α, and is the only mAb approved by the European Medicine Agency and US Food and Drug Administration for the treatment of EoE. Other mAbs investigated include mepolizumab, reslizumab, and benralizumab (interfering with IL-5 axis), cendakimab and dectrekumab (anti-IL-13s), tezepelumab (anti-TSLP), lirentelimab (anti-SIGLEG-8), and many others. Despite the undeniable economic impact of biologic therapies, in the near future, there will be room for further reflection about the opportunity to prescribe biologic agents, not only as a last-line therapy in selected cases such as patients with comorbidities involving common pathways. Although recent findings are very encouraging, the road to permanent success in the treatment of EoE is still long, and further studies are needed to determine the long-term effects of mAbs and to discover new potential targets.

Fibrous Remodeling in Eosinophilic Esophagitis: Clinical Facts and Pathophysiological Uncertainties

Eosinophilic esophagitis (EoE) is a chronic, progressive, type 2 inflammatory disease with increasing global prevalence. An eosinophil-predominant inflammation that permeates the epithelium and deeper esophageal layers characterizes the disease. Several cytokines, mainly derived from inflammatory T-helper 2 (Th2) cells and epithelial cells, are involved in perpetuating inflammatory responses by increasing surface permeability and promoting tissue remodeling characterized by epithelial-mesenchymal transition (EMT) and collagen deposition. This leads to esophageal strictures and narrow caliber esophagi, which are proportional a patient's age and untreated disease length. Pathophysiological mechanisms leading to EoE have been described in recent years, and transforming growth factor beta (TGF)-beta have been involved in fibrotic phenomena in EoE. However, evidence on the dependence of these phenomena on TGF-beta is scarce and contradictory. This review provides state-of-the art knowledge on intimate mechanisms of esophageal fibrosis in EoE and its clinical consequences.

Retrospective cohort study: Effect of age as a barrier to diagnosis of eosinophilic oesophagitis

BACKGROUND

Prior work suggests eosinophilic oesophagitis (EoE) is rare in those aged over 65 years. However, elderly patients with EoE experience a substantial diagnostic delay from symptom onset to diagnosis.

AIMS

To assess if age predicted whether oesophageal biopsies were obtained in patients with EoE symptoms, what clinical features predict EoE in the elderly, and if EoE phenotype differs between elderly and non-elderly patients.

METHODS

We conducted a retrospective cohort study utilising the University of North Carolina (UNC) electronic medical record, EoE clinicopathologic database and UNC endoscopy software from July 2008 to April 2021. A sample of 193 elderly and non-elderly patients with dysphagia, chest pain and/or heartburn were assembled. Patients with EoE were newly diagnosed per contemporaneous guidelines. Patient demographics, clinical characteristics and procedural data were extracted. Summary statistics, bivariate and multivariate analyses were performed.

RESULTS

Of 193 patients, we included 91 elderly (47%) and 102 non-elderly (53%). Age independently predicted the odds of biopsies (adjusted odds ratio (aOR): 0.44 elderly vs. non-elderly; 95% CI: 0.21-0.92). Endoscopic features of EoE, but not symptoms, were more common in elderly than non-EoE elderly patients. Elderly patients with EoE differed from non-elderly only by time to diagnosis (aOR per year of symptoms preceding diagnosis: 1.08, 95% CI: 1.04-1.11).

CONCLUSIONS

Elderly patients with EoE have <50% the odds of oesophageal biopsies. There were no significant differences between elderly and non-elderly EoE patients, although endoscopic features helped discriminate the two groups. Our findings suggest that older age represents a barrier to EoE diagnosis.

Joint ESPGHAN/NASPGHAN Guidelines on Childhood Eosinophilic Gastrointestinal Disorders Beyond Eosinophilic Esophagitis

INTRODUCTION

Eosinophilic gastrointestinal disorders beyond eosinophilic esophagitis (non-EoE EGIDs) are rare chronic inflammatory disorders of the gastrointestinal (GI) tract. Diagnosis is based on clinical symptoms and histologic findings of eosinophilic inflammation after exclusion of a secondary cause or systemic disease. Currently, no guidelines exist for the evaluation of non-EoE EGIDs. Therefore, the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) formed a task force group to provide consensus guidelines for childhood non-EoE EGIDs.

METHODS

The working group was composed of pediatric gastroenterologists, adult gastroenterologists, allergists/immunologists, and pathologists. An extensive electronic literature search of the MEDLINE, EMBASE, and Cochrane databases was conducted up to February 2022. General methodology was used in the formulation of recommendations according to the Appraisal of Guidelines for Research and Evaluation (AGREE) II and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to meet current standards of evidence assessment.

RESULTS

The guidelines provide information on the current concept of non-EoE EGIDs, disease pathogenesis, epidemiology, clinical manifestations, diagnostic and disease surveillance procedures, and current treatment options. Thirty-four statements based on available evidence and 41 recommendations based on expert opinion and best clinical practices were developed.

CONCLUSION

Non-EoE EGIDs literature is limited in scope and depth, making clear recommendations difficult. These consensus-based clinical practice guidelines are intended to assist clinicians caring for children affected by non-EoE EGIDs and to facilitate high-quality randomized controlled trials of various treatment modalities using standardized, uniform disease definitions.

IL-13-induced STAT3-dependent signaling networks regulate esophageal epithelial proliferation in eosinophilic esophagitis

BACKGROUND

Basal zone hyperplasia (BZH) and dilated intercellular spaces (DISs) are thought to contribute to the clinical manifestations of eosinophilic esophagitis (EoE); however, the molecular pathways that drive BZH remain largely unexplored.

OBJECTIVE

We sought to define the role of IL-13-induced transcriptional programs in esophageal epithelial proliferation in EoE.

METHODS

We performed RNA sequencing, bioinformatics, Western blot, reverse transcriptase quantitative PCR, and histologic analyses on esophageal biopsies from healthy control and patients with EoE, primary esophageal cells derived from patients with EoE, and IL-13-stimulated esophageal epithelial keratinocytes grown at the air-liquid interface (EPC2-ALI). Genetic (shRNA) and pharmacologic (proteolysis-targeting chimera degrader) approaches and in vivo model of IL-13-induced esophageal epithelial remodeling (Krt5-rtTA x tetO-IL-13Tg) were used to define the role of signal transducer and activator of transcription 3 (STAT3) and STAT6 and secreted frizzled-related protein 1 (SFRP1) in esophageal epithelial proliferation.

RESULTS

RNA-sequencing analysis of esophageal biopsies (healthy control vs EoE) and EPC2-ALI revealed 82 common differentially expressed genes that were enriched for putative STAT3 target genes. In vitro and in vivo analyses revealed a link between IL-13-induced STAT3 and STAT6 phosphorylation, SFRP1 mRNA expression, and esophageal epithelial proliferation. In vitro studies showed that IL-13-induced esophageal epithelial proliferation was STAT3-dependent and regulated by the STAT3 target SFRP1. SFRP1 mRNA is increased in esophageal biopsies from patients with active EoE compared with healthy controls or patients in remission and identifies an esophageal suprabasal epithelial cell subpopulation that uniquely expressed the core EoE proinflammatory transcriptome genes (CCL26, ALOX15, CAPN14, ANO1, and TNFAIP6).

CONCLUSIONS

These studies identify SFRP1 as a key regulator of IL-13-induced and STAT3-dependent esophageal proliferation and BZH in EoE and link SFRP1+ esophageal epithelial cells with the proinflammatory and epithelial remodeling response in EoE.

Breakthroughs in understanding and treating eosinophilic gastrointestinal diseases presented at the CEGIR/TIGERs Symposium at the 2022 American Academy of Allergy, Asthma & Immunology Meeting

The Consortium of Eosinophilic Gastrointestinal Diseases and The International Gastrointestinal Eosinophil Researchers organized a day-long symposium at the 2022 Annual Meeting of the American Academy of Allergy, Asthma & Immunology. The symposium featured a review of recent discoveries in the basic biology and pathogenesis of eosinophilic gastrointestinal diseases (EGIDs) in addition to advances in our understanding of the clinical features of EGIDs. Diagnostic and management approaches were reviewed and debated, and clinical trials of emerging therapies were highlighted. Herein, we briefly summarize the breakthrough discoveries in EGIDs.

Race and Gender Influences the Presentation of Eosinophilic Esophagitis

Our understanding of the influence of race and gender on the presentation of eosinophilic esophagitis (EoE) is incomplete. To address this gap, we examined the effect of race and gender on the presentation of EoE. In this retrospective study, we reviewed the medical records of 755 EoE patients and recorded their demographic, clinical, endoscopic, and histologic information. Descriptive statistics were used to characterize the cohort. Multivariate logistic regression was used to identify predictors of race and gender after accounting for potential confounders. There was a bimodal distribution for age at diagnosis of EoE. Approximately 43% had pediatric onset EoE, while 57% had adult onset EoE. Male (68%) predominance was observed. Dysphagia (57%) and abdominal pain (20%) were among the most common presenting symptoms. Multivariate analysis revealed that African Americans (AAs) were diagnosed earlier [aOR: 0.96 (95% CI: 0.95-0.99); P = 0.01] and had significantly lower odds of manifesting furrows [aOR: 0.30 (95% CI: 0.12-0.77); P = 0.01] as compared with Whites. Males were diagnosed earlier [aOR 0.98 (0.97-0.99; P = 0.04] and had higher odds of having abnormal endoscopic findings [aOR: 1.43 (1.05-1.97); P = 0.02] when compared with females. Race and gender influence the presentation of EoE. Future studies aimed at investigating the interplay between race, gender, and molecular mechanisms of EoE are warranted.

Histological Phenotyping in Eosinophilic Esophagitis: Localized Proximal Disease Is Infrequent but Associated with Less Severe Disease and Better Disease Outcome

INTRODUCTION

It is still unknown whether eosinophilic esophagitis (EoE) patients with localized disease are different from those with extended disease.

METHODS

We evaluated prospectively included patients in the Swiss EoE cohort. Data on all patients with active disease at baseline, no concomitant gastroesophageal reflux disease, no strictures at baseline, and at least one follow-up visit were analyzed. We compared patients with histologically localized proximal versus distal versus extended (=proximal and distal) disease with regard to patient, disease characteristics, disease presentation, and development of complications.

RESULTS

We included 124 patients with a median of 2.5 years of follow-up (73.4% males, median age 35.0 years). Ten patients had proximal (8.1%), 46 patients had distal (37.1%), and 68 patients had extended disease (54.8%). Patients with proximal disease were significantly more often females (80%) compared with patients with distal (26.1%, p = 0.002) or extended disease (19.1%, p < 0.001) and reported less severe symptoms (VAS 0 vs. VAS 1, p = 0.001). Endoscopic and histological disease was less pronounced in the proximal esophagus of proximal EoE compared to extended disease (EREFS 1.0 vs. 3.0, p = 0.001; 27.0 eos/hpf vs. 52.5 eos/hpf, p = 0.008). Patients with proximal disease were less likely to undergo dilation compared to patients with distal disease in the follow-up (3.3% vs. 23.3%, p = 0.010). In a multivariate Cox regression model, proximal eosinophilia was less likely to be associated with treatment failure compared to distal eosinophilia.

CONCLUSION

Although isolated proximal EoE is infrequent, it is associated with less severe disease and better disease outcome. Proximal disease appears to present a unique EoE phenotype.