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.

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.

Helicobacter pylori infection found during upper endoscopy performed for the diagnosis of celiac, inflammatory bowel diseases, and eosinophilic esophagitis: A multicenter pediatric European study.

BACKGROUND: Helicobacter pylori may be found during upper gastrointestinal endoscopy (UGE) performed to diagnose celiac disease (CeD), inflammatory bowel disease (IBD), and eosinophilic esophagitis (EoE). We aimed to describe the frequency of H. pylori in children undergoing UGE for CeD, IBD, and EoE and the number of children receiving eradication treatment. MATERIALS AND METHODS: A retrospective multicenter study from 14 countries included pediatric patients diagnosed with CeD, IBD, and EoE between January 2019 and December 2021. DATA COLLECTED: age, gender, hematologic parameters, endoscopic, histologic, and H. pylori culture results, and information on eradication treatment. RESULTS: H. pylori was identified in 349/3890 (9%) children [167 (48%) male, median 12 years (interquartile range 8.1-14.6)]. H. pylori was present in 10% (173/1733) CeD, 8.5% (110/1292) IBD and 7.6% (66/865) EoE patients (p = NS). The prevalence differed significantly between Europe (Eastern 5.2% (28/536), Southern 3.8% (78/2032), Western 5.6% (28/513)) and the Middle East 26.6% (215/809) [odds ratio (OR) 7.96 95% confidence interval (CI) (6.31-10.1) p < 0.0001]. Eradication treatment was prescribed in 131/349 (37.5%) patients, 34.6% CeD, 35.8% IBD, and 56.1% EoE. Predictors for recommending treatment included erosions/ulcers [OR 6.45 95% CI 3.62-11.47, p < 0.0001] and nodular gastritis [OR 2.25 95% CI 1.33-3.81, p 0.003]. Treatment rates were higher in centers with a low H. pylori prevalence (<20%) [OR 3.36 95% CI 1.47-7.66 p 0.004]. CONCLUSIONS: Identifying H. pylori incidentally during UGE performed for the most common gastrointestinal diseases varies significantly among regions but not among diseases. The indications for recommending treatment are not well defined, and less than 40% of children received treatment.

Causality of Helicobacter pylori infection on eosinophilic esophagitis and potential pathogenesis: a Mendelian randomization study.

Background: Observational studies have indicated a possible connection between Helicobacter pylori (H. pylori) infection and eosinophilic esophagitis (EoE), but their causal relationship has yet to be established. To investigate the causal associations between H. pylori infection and EoE, we performed a Mendelian randomization (MR) analysis. Methods: Firstly, we conducted both univariable and multivariable Mendelian randomization (MR) analyses. Furthermore, a two-step MR was carried out to ascertain the potential underlying pathways of these associations, particularly the involvement of inflammatory cytokines. We employed the inverse-variance weighted (IVW) method as the main analysis in our MR study. To enhance the credibility of the results, we also conducted several sensitivity analyses. Results: Our study demonstrated a noteworthy correlation between genetically predicted anti-H. pylori IgG antibody levels and a reduced risk of EoE (OR=0.325, 95% CI=0.165-0.643, P value=0.004, adj p value=0.009). No significant causal associations were detected between other H. pylori antibodies and EoE in our study. When it comes to multivariable MR analysis controlling for education attainment, household income, and deprivation individually, the independent causal impact of anti-H. pylori IgG on EoE persisted. Surprisingly, the two-step MR analysis indicated that inflammatory factors (IL-4, IL-5, IL-13, IL-17, and IFN-γ) did not appear to mediate the protective effect of H. pylori infection against EoE. Conclusion: Findings suggested that among the range of H. pylori-related antibodies, anti-H. pylori IgG antibody is the sole causal factor associated with protection against EoE. Certain inflammatory factors may not be involved in mediating this association. These findings make a significant contribution to advancing our understanding of the pathogenesis of EoE and its evolving etiology.

Eosinophilic Esophagitis: A Review for the Primary Care Practitioner.

This chapter presents an overview of eosinophilic esophagitis (EoE) for the Primary Care Practitioner (PCP). The focus is on helping PCPs keep it in their differential diagnosis by discussing the spectrum of clinical presentations, how to screen for EoE in at-risk populations and subsequently manage the patient with this condition. The authors review epidemiology, risk factors and associated conditions, pathology, clinical presentation, diagnosis, and management options.

Three-Dimensional Cell Culture Models to Investigate the Epithelial Barrier in Eosinophilic Esophagitis.

The squamous epithelium of the esophagus is directly exposed to the environment, continuously facing foreign antigens, including food antigens and microbes. Maintaining the integrity of the epithelial barrier is critical for preventing infections and avoiding inflammation caused by harmless food-derived antigens. This article provides simplified protocols for generating human esophageal organoids and air-liquid interface cultures from patient biopsies to study the epithelial compartment of the esophagus in the context of tissue homeostasis and disease. These protocols have been significant scientific milestones in the last decade, describing three-dimensional organ-like structures from patient-derived primary cells, organoids, and air-liquid interface cultures. They offer the possibility to investigate the function of specific cytokines, growth factors, and signaling pathways in the esophageal epithelium within a three-dimensional framework while maintaining the phenotypic and genetic properties of the donor. Organoids provide information on tissue microarchitecture by assessing the transcriptome and proteome after cytokine stimulation. In contrast, air-liquid interface cultures allow the assessment of the epithelial barrier integrity through transepithelial resistance (TEER) or macromolecule flux measurements. Combining these organoids and air-liquid interface cultures is a powerful tool to advance research in impaired esophageal epithelial barrier conditions.

Swallowed topical steroid therapy for eosinophilic oesophagitis in children: practical, evidence-based guidance by the BSPGHAN Eosinophilic Oesophagitis Working Group.

OBJECTIVE: To develop evidence-based guidance for topical steroid use in paediatric eosinophilic oesophagitis (pEoE) in the UK for both induction and maintenance treatment. METHODS: A systematic literature review using Cochrane guidance was carried out by the British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) Eosinophilic Oesophagitis (EoE) Working Group (WG) and research leads to determine the evidence base for preparation, dosing and duration of use of swallowed topical steroid (STS) formulations in EoE. Seven themes relating to pEoE were reviewed by the WG, alongside the Cochrane review this formed the evidence base for consensus recommendations for pEoE in the UK. We provide an overview of practical considerations including treatment regimen and dosing. Oral viscous budesonide (OVB) and, if agreed by local regulatory committees, orodispersible budesonide (budesonide 1 mg tablets) were selected for ease of use and with most improvement in histology. A practical 'how to prepare and use' OVB appendix is included. Side effects identified included candidiasis and adrenal gland suppression. The use of oral systemic steroids in strictures is discussed briefly. RESULTS: 2638 citations were identified and 18 randomised controlled trials were included. Evidence exists for the use of STS for induction and maintenance therapy in EoE, especially regarding histological improvement. Using the Appraisal of Guidelines, Research and Evaluation criteria, dosing of steroids by age (0.5 mg two times per day <10 years and 1 mg two times per day ≥10 years) for induction of at least 3 months was suggested based on evidence and practical consideration. Once histological remission is achieved, maintenance dosing of steroids appears to reduce the frequency and severity of relapse, as such a maintenance weaning regimen is proposed. CONCLUSION: A practical, evidence-based flow chart and guidance recommendations with consensus from the EoE WG and education and research representatives of BSPGHAN were developed with detailed practical considerations for use in the UK.

Causal relationship between eosinophilic esophagitis and inflammatory bowel disease: a bidirectional two-sample Mendelian randomization study.

Background: Eosinophilic esophagitis (EoE) and inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis (UC), are immune-mediated gastrointestinal diseases with overlapped pathogenesis and are sometimes concurrently diagnosed, but their causal relationship remains unclear. We investigated the causal relationship between EoE and IBD and its subtypes via a two-sample bidirectional Mendelian randomization (MR) approach. Methods: MR analyses were performed using summary data of a genome-wide association study (GWAS) on individuals of European ancestry. Independent single-nucleotide polymorphisms correlated with EoE (from a GWAS meta-analysis containing 1,930 cases and 13,634 controls) and IBD (from FinnGen GWASs containing 9,083 IBD, 2,033 CD, and 5,931 UC cases, and GWASs of IBD genetic consortium containing 12,882 IBD, 6,968 UC, and 5,956 CD cases) were selected as instruments. We applied the inverse variance weighted (IVW) method as the primary analysis followed by several sensitivity analyses. For the forward MR study, estimates from IVW methods were subsequently meta-analyzed using a random-effect model. Results: Our results suggested a causal effect of EoE on IBD [pooled odds ratio (OR), 1.07; 95% confidence interval (CI), 1.02-1.13] and EoE on UC (pooled OR, 1.09, 95% CI, 1.04-1.14). No causal link between EoE and CD was observed (pooled OR, 1.05; 95% CI, 0.96-1.16). The reverse MR analyses revealed no causal effect of IBD (and its subtypes) on EoE. Sensitivity analyses confirmed the robustness of primary results. Conclusions: Our findings provided evidence of a suggestive causal effect of EoE on IBD (specifically on UC) in the European population. Increased awareness of concurrent or subsequent IBD in patients with EoE is called for. Still, the present evidence is not adequate enough and ought to be validated by further investigations.

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.

Eosinophilic esophagitis: Does age matter?

OBJECTIVES: Eosinophilic esophagitis (EoE) is often diagnosed in school-age children between 6- and 9-year-old. There is less known about those who are diagnosed with EoE that are younger than 6 years old. The objective of this study is to compare clinical presentation, comorbidities, and outcomes based on age at diagnosis of EoE. METHODS: Single-center retrospective chart review of children (<18 years) diagnosed with EoE between 2005 and 2020. We recorded demographics, clinical presentation, family history, past medical history, treatment, and endoscopic findings. Children in this cohort were classified based on age into three age groups: <2 years, 2-<6 years, and 6-<18 years. RESULTS: We identified 256 children with EoE, the mean age (SD) at the time of diagnosis was 9 (5.2) years and 184 (72%) were male. We had 164 (64%) patients with available follow-up esophagogastroduodenoscopies (EGDs) data (495 EGDs in total) of those 99/164 (60%) reached mucosal remission. In the very young children (<2 years) vomiting was the most common presentation, while poor weight gain was seen more in the 2-<6-year group in comparison to the >6-years. Food impaction and abdominal pain were most likely to present in older children 6-18 years. Combination therapy, as opposed to a single therapy, induced remission at a higher frequency in the <6-year group in comparison to the 6-<18-year group (85% vs. 66%). CONCLUSION: EoE should be considered in younger children presenting with feeding difficulty and poor weight gain. Combination therapy seems to be more effective in younger children with EoE, but further studies with bigger sample size are needed to study the efficacy of the different combination therapies.

Dupilumab in adolescent eosinophilic esophagitis: Experience with fibrostenosis and eosinophilic gastrointestinal disease with esophageal involvement.

We evaluated patients aged 12-20 on dupilumab 300 mg weekly for treatment of eosinophilic esophagitis (EoE) who had ≥1 follow-up endoscopy at a tertiary care pediatric hospital (n = 18). Fifty percent had inflammatory EoE (n = 9), 22% had fibrostenotic EoE (n = 4), and 28% had non-EoE eosinophilic gastrointestinal disease (EGID) with esophageal involvement (n = 5). Ninety-four percent discontinued topical corticosteroids (TCS) 2-4 weeks after starting dupilumab. Eighty-nine percent of inflammatory EoE patients had histological response (<15 eosinophils/high-powered field) after an average of 19.1 weeks. One hundred percent of patients with fibrostenotic disease exhibited histological response after 16.8 weeks. Of patients with non-EoE EGID, 60% achieved esophageal histological response after an average of 40.1 weeks. In a small cohort, dupilumab was very effective for adolescent inflammatory and fibrostenotic EoE despite rapid weaning of TCS. Dupilumab was also somewhat effective for non-EoE EGID with esophageal involvement; however, a longer duration of therapy was required.

Esophageal remodeling in eosinophilic esophagitis.

PURPOSE OF REVIEW: Eosinophilic esophagitis (EoE) is a Th2 immune/antigen-mediated disorder characterized by esophageal dysfunction and eosinophilic inflammation. Worsening dysphagia and food impactions are significant complications associated with esophageal remodeling and fibrostenotic disease. This review highlights the most recent research findings pertaining to mechanisms of sub-epithelial fibrosis in EoE, current diagnostic tools, and therapeutic approaches. RECENT FINDINGS: Recent studies leveraging publicly available single cell sequencing databases and comparative proteomics have furthered our understanding of the mechanisms mediating fibrosis. Fibroblast crosstalk with the extracellular matrix and with epithelial, endothelial, and T cells have been implicated, with the likely existence of multiple fibroblast sub-types. Accurate diagnosis of remodeling with biopsies remains a challenge due to inadequate depth of sampling. Web-based tools incorporating epithelial findings show promise in predicting subepithelial fibrosis. Impedance planimetry with esophageal distensibility measurements are increasingly utilized tools to assess fibrostenotic severity. Immunostaining and luminal captured proteins associated with remodeling show promise as potential molecular markers of fibrosis. Anti-inflammatory therapy may improve esophageal fibrosis and distensibility, although specific fibrosis-targeted therapy is lacking. SUMMARY: Recent studies highlight novel mechanisms of fibrosis in EoE. Improved understanding of these mechanisms may lead to novel diagnostic strategies and therapies, and thereby inform treatment decisions.

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.

Pathophysiology of Non-Esophageal Eosinophilic Gastrointestinal Disorders.

Eosinophilic gastrointestinal disorder (EGID) is an umbrella term encompassing a group of chronic, immune-mediated disorders characterized by eosinophil-rich inflammation affecting one or more segments of the gastrointestinal tract. A recent consensus in nomenclature and emerging data made possible through multi-center consortia are beginning to unravel the molecular and cellular underpinnings of EGIDs below the esophagus. These emerging findings are revealing both overarching commonalities related to a food allergen-driven, chronic, Th2-mediated immune response as well as location-specific nuances in the pathophysiology of the collective EGIDs. Altogether, these advances offer promise for improved diagnoses and more efficacious interventional strategies.

Monitoring and modulating the trajectory of eosinophilic esophagitis.

Current treatments of eosinophilic esophagitis (EoE) aim to eliminate esophageal mucosal inflammation and attenuate, stabilize, or reverse stricture formation. However, our ability to study the long-term course of esophageal strictures in patients with EoE is hampered by the short-term existence of this disease. It is unclear to what degree of control of inflammation is needed to prevent stricture formation. Additionally, identified phenotypes of EoE may ultimately dictate different levels of concern and time intervals for developing fibrosis. Currently, multiple methods are used to monitor patients' disease progression to fibrosis, as symptoms alone do not correlate with disease activity. Endoscopic findings and mucosal histology are used to monitor disease activity, but these focus on improvements in inflammation with inconsistent evaluation of underlying fibrosis. The use of functional lumen impedance planimetry, barium esophagraphy, and endoscopic ultrasound continues to expand in EoE. The rapid advancements in EoE have led to an armamentarium of measuring tools and therapies that holistically characterize disease severity and response to therapy. Nevertheless, our ability to evaluate gross esophageal fibrosis and stricture formation from a transmural rather than mucosal view should be a focus of future investigations because it is essential to monitoring and modulating the trajectory of EoE.

Eosinophilic Esophagitis: Clinical Pearls for Primary Care Providers and Gastroenterologists.

Eosinophilic esophagitis (EoE) is a chronic and progressive immune-mediated esophageal disorder. Given its increasing incidence, it is now a leading cause of dysphagia and food impaction in the United States. Eosinophilic esophagitis is most common in adult White men and has a high concurrence rate with other atopic conditions like allergic rhinitis, bronchial asthma, and eczema. The initial presentation includes symptoms of esophageal dysfunction, classically solid-food dysphagia. Without treatment, inflammation can progress to fibrosis with the formation of strictures, leading to complications such as food impaction. It is a clinicopathologic disease requiring compatible clinical symptoms and histologic evidence of eosinophil-predominant inflammation of the esophageal epithelium with more than 15 eosinophils per high-power field. The mainstay of management includes the 3 d's (diet, drugs, dilation): dietary modifications to eliminate trigger food groups; medications including proton pump inhibitors, swallowed topical glucocorticoids, and dupilumab; and esophageal dilation to manage strictures. Various elimination diets have been found to be effective, including 1-food, 2-food, 4-food, and 6-food elimination diets. Dupilumab, a humanized monoclonal antibody that regulates interleukin 4 and 13 signaling pathways, has shown promising results in clinical trials and was approved by the Food and Drug Administration in 2022 for use in EoE. Symptom alleviation, although important, is not the sole end point of treatment in EoE as persistent inflammation, even in the absence of symptoms, can lead to esophageal fibrosis and stricture formation over time. The chronic nature and high recurrence rates of EoE warrant maintenance therapy in patients with EoE after initial remission is achieved.

Endoscopic findings in children born with oesophageal atresia in an academic unit in South Africa.

BACKGROUND: Oesophageal atresia (OA) is one of the most common congenital gastrointestinal (GI) abnormalities. Due to advances in multidisciplinary care, early prognosis has improved with emphasis shifting to the long-term impact of this disease. Literature suggests a higher incidence of Barrett's and eosinophilic oesophagitis in these children, with an increased risk of oesophageal carcinoma. Guidelines for adults born with OA include routine endoscopy and lifelong screening of the upper gastrointestinal tract (GIT). Despite this, uncertainty remains regarding the necessity and frequency of endoscopic surveillance for children born with OA. We describe our endoscopic findings in children born with OA. METHODS: A prospective analytic cohort study was undertaken, which included all children born with OA, that were followed-up in our unit between 2020 and 2022. History regarding feeding and GI symptoms were documented after which an endoscopy was performed. RESULTS: During the study period, 37 endoscopies were performed in patients born with OA at a median age of 25 months. The most common clinical appearance on endoscopy was anastomotic strictures followed by oesophagitis. Twelve patients had biopsies taken, with abnormal histology in all but one patient. The most common histological finding was oesophagitis with lymphocytes and chronic gastritis. Two patients had Helicobacter Pylori infection, and one had findings suggestive of eosinophilic oesophagitis. CONCLUSION: All patients with a clinical indication for an endoscopy had abnormal clinical or histological findings, thus concurring with the literature in highlighting the need for regular endoscopy. We recommend regular clinical follow-up and endoscopic surveillance if clinically indicated for children born with OA.

Impact of STAT6 Variants on the Response to Proton Pump Inhibitors and Comorbidities in Patients with Eosinophilic Esophagitis.

Proton pump inhibitors (PPIs) are the first-line drug for eosinophilic esophagitis (EoE), although it is estimated that there is a lack of histological remission in 50% of patients. This research aimed to identify pharmacogenetic biomarkers predictive of PPI effectiveness and to study their association with disease features. Peak eosinophil count (PEC) and the endoscopic reference score (EREFS) were determined before and after an eight-week PPI course in 28 EoE patients. The impact of the signal transducer and activator of transcription 6 (STAT6), CYP2C19, CYP3A4, CYP3A5, and ABCB1 genetic variations on baseline PEC and EREFS, their reduction and histological response, and on EoE symptoms and comorbidities was analyzed. PEC reduction was higher in omeprazole-treated patients (92.5%) compared to other PPIs (57.9%, p = 0.003). STAT6 rs12368672 (g.18453G>C) G/G genotype showed higher baseline PEC values compared to G/C and C/C genotypes (83.2 vs. 52.9, p = 0.027). EREFS reduction in STAT6 rs12368672 G/G and G/C genotypes was higher than in the C/C genotype (36.7% vs. -75.0% p = 0.011). However, significance was lost after Bonferroni correction. Heartburn incidence was higher in STAT6 rs167769 (g.27148G>A) G/G patients compared to G/A (54.55% vs. 11.77%, p = 0.030). STAT6 rs12368672G>C and rs167769G>A variants might have a relevant impact on EoE status and PPI response. Further research is warranted to clarify the clinical relevance of these variants.