Contribution of T cell subsets to different food allergic diseases.

Food allergies occur due to a lack of tolerance to the proteins found in foods. While IgE- and non-IgE-mediated food allergies have different clinical manifestations, epidemiology, pathophysiology, and management, they share dysregulated T cell responses. Recent studies have shed light on the contributions of different T cell subsets to the development and persistence of different food allergic diseases. This review discusses the role of T cells in both IgE- and non-IgE-mediated food allergies and considers the potential future investigations in this context.

Systematic identification of genotype-dependent enhancer variants in eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is a rare atopic disorder associated with esophageal dysfunction, including difficulty swallowing, food impaction, and inflammation, that develops in a small subset of people with food allergies. Genome-wide association studies (GWASs) have identified 9 independent EoE risk loci reaching genome-wide significance (p < 5 × 10-8) and 27 additional loci of suggestive significance (5 × 10-8 < p < 1 × 10-5). In the current study, we perform linkage disequilibrium (LD) expansion of these loci to nominate a set of 531 variants that are potentially causal. To systematically interrogate the gene regulatory activity of these variants, we designed a massively parallel reporter assay (MPRA) containing the alleles of each variant within their genomic sequence context cloned into a GFP reporter library. Analysis of reporter gene expression in TE-7, HaCaT, and Jurkat cells revealed cell-type-specific gene regulation. We identify 32 allelic enhancer variants, representing 6 genome-wide significant EoE loci and 7 suggestive EoE loci, that regulate reporter gene expression in a genotype-dependent manner in at least one cellular context. By annotating these variants with expression quantitative trait loci (eQTL) and chromatin looping data in related tissues and cell types, we identify putative target genes affected by genetic variation in individuals with EoE. Transcription factor enrichment analyses reveal possible roles for cell-type-specific regulators, including GATA3. Our approach reduces the large set of EoE-associated variants to a set of 32 with allelic regulatory activity, providing functional insights into the effects of genetic variation in this disease.

Persistent esophageal changes after histologic remission in eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is characterized by persistent or relapsing allergic inflammation, and both clinical and histologic features of esophageal inflammation persist over time in most individuals. Mechanisms contributing to EoE relapse are not understood, and chronic EoE-directed therapy is therefore required to prevent long-term sequelae. OBJECTIVE: We investigated whether EoE patients in histologic remission have persistent dysregulation of esophageal gene expression. METHODS: Esophageal biopsy samples from 51 pediatric and 52 adult subjects with EoE in histopathologic remission (<15 eosinophils per high-power field [eos/hpf]) and control (48 pediatric and 167 adult) subjects from multiple institutions were subjected to molecular profiling by the EoE diagnostic panel, which comprises a set of 94 esophageal transcripts differentially expressed in active EoE. RESULTS: Defining remission as <15 eos/hpf, we identified 51 and 32 differentially expressed genes in pediatric and adult EoE patients compared to control individuals, respectively (false discovery rate < 0.05). Using the stringent definition of remission (0 eos/hpf), the adult and pediatric cohorts continued to have 18 and 25 differentially expressed genes (false discovery rate < 0.05). Among 6 shared genes between adults and children, CDH26 was upregulated in both children and adults; immunohistochemistry demonstrated increased cadherin 26 staining in the epithelium of EoE patients in remission compared to non-EoE controls. In the adult cohort, POSTN expression correlated with the endoscopic reference system score (Spearman r = 0.35, P = .011), specifically correlating with the rings' endoscopic reference system subscore (r = 0.53, P = .004). CONCLUSION: We have identified persistent EoE-associated esophageal gene expression in patients with disease in deep remission. These data suggest potential inflammation-induced epigenetic mechanisms may influence gene expression during remission in EoE and provide insight into possible mechanisms that underlie relapse in EoE.

Real-World Efficacy of Dupilumab in Severe, Treatment-Refractory, and Fibrostenotic Patients With Eosinophilic Esophagitis.

BACKGROUND & AIMS: Dupilumab is approved for treatment of eosinophilic esophagitis (EoE), but real-world data are lacking. We aimed to determine the real-world efficacy of dupilumab in patients with severe, treatment-refractory, and fibrostenotic EoE. METHODS: We conducted a retrospective cohort study of EoE patients prescribed dupilumab and who were treatment-refractory to standard modalities. Patient demographics, clinical characteristics, EoE history, and procedural data (including the histologically worst, predupilumab, and postdupilumab endoscopies) were extracted from medical records. Symptomatic, endoscopic, and histologic responses were assessed for the worst and predupilumab endoscopies compared with the postdupilumab endoscopy. RESULTS: We identified 46 patients with refractory fibrostenotic EoE who were treated with dupilumab. Patients showed endoscopic, histologic, and symptomatic improvement on dupilumab compared with both the worst and the predupilumab esophagogastroduodenoscopies. The peak eosinophil counts decreased markedly, and postdupilumab histologic response rates were 80% and 57% for fewer than 15 eosinophils per high-power field and 6 or fewer eosinophils per high-power field, respectively, and the Endoscopic Reference Score decreased from 5.01 to 1.89 (P < .001 for all). Although the proportion of strictures was stable, there was a significant increase in the predilation esophageal diameter (from 13.9 to 16.0 mm; P < .001). Global symptom improvement was reported in 91% (P < .001). CONCLUSIONS: In this population of severe, refractory, and fibrostenotic EoE patients, most achieved histologic, endoscopic, and symptom improvement with a median of 6 months of dupilumab, and esophageal stricture diameter improved. Dupilumab has real-world efficacy for a severe EoE population, most of whom would not have qualified for prior clinical trials.

Esophageal Distensibility Defines Fibrostenotic Severity in Pediatric Eosinophilic Esophagitis.

BACKGROUND & AIMS: Identification of fibrosis in pediatric eosinophilic esophagitis (EoE) relies on symptom assessment and endoscopy. Symptoms are highly variable, and early fibrotic remodeling may go undetected on endoscopy yet contribute to esophageal dysfunction. We aimed to assess whether esophageal distensibility has utility in defining fibrostenotic severity in a cohort of pediatric patients with EoE with symptoms of esophageal dysfunction. METHODS: We analyzed a prospectively recruited a cohort of children ages 9 to 21 years undergoing upper endoscopy and Endoscopic Functional Lumen Imaging Probe (EndoFLIP) for suspected or previously diagnosed EoE. Esophageal distensibility was evaluated by the distensibility index (DI) and esophageal diameter at the distensibility plateau. The association of esophageal distensibility to clinical, endoscopic, and histologic parameters of disease severity was assessed. Receiver operating characteristic analysis was performed to determine the utility of distensibility in defining esophageal rigidity in pediatric EoE. RESULTS: We identified 59 pediatric patients with EoE undergoing endoscopy and EndoFLIP at a single pediatric tertiary referral center. DI (mm2/mmHg) was significantly lower in patients with fibrotic as compared with inflammatory features on endoscopy (median, 3.3; interquartile range, 2.3-4.4) vs median, 5.5; interquartile range, 4.1-6.0; P = .02) and showed no correlation with eosinophil count. DI <4.5 mm2/mmHg predicted grade 2 rings on endoscopy with area under the curve of 0.81 (P = .0004). DI predicted food impaction in both unadjusted and adjusted models (fully adjusted odds ratio, 1.44; 95% confidence interval, 1.02-2.14; P = .0486). CONCLUSION: Esophageal distensibility determined by EndoFLIP is a measure of fibrostenotic severity that can be used to clinically phenotype pediatric EoE. We propose parameters of DI <4.5 mm2/mmHg for defining esophageal rigidity in pediatric patients with EoE ages 9 years and older.

Performance of an Artificial Intelligence Model for Recognition and Quantitation of Histologic Features of Eosinophilic Esophagitis on Biopsy Samples.

We have developed an artificial intelligence (AI)-based digital pathology model for the evaluation of histologic features related to eosinophilic esophagitis (EoE). In this study, we evaluated the performance of our AI model in a cohort of pediatric and adult patients for histologic features included in the Eosinophilic Esophagitis Histologic Scoring System (EoEHSS). We collected a total of 203 esophageal biopsy samples from patients with mucosal eosinophilia of any degree (91 adult and 112 pediatric patients) and 10 normal controls from a prospectively maintained database. All cases were assessed by a specialized gastrointestinal (GI) pathologist for features in the EoEHSS at the time of original diagnosis and rescored by a central GI pathologist (R.K.M.). We subsequently analyzed whole-slide image digital slides using a supervised AI model operating in a cloud-based, deep learning AI platform (Aiforia Technologies) for peak eosinophil count (PEC) and several histopathologic features in the EoEHSS. The correlation and interobserver agreement between the AI model and pathologists (Pearson correlation coefficient [rs] = 0.89 and intraclass correlation coefficient [ICC] = 0.87 vs original pathologist; rs = 0.91 and ICC = 0.83 vs central pathologist) were similar to the correlation and interobserver agreement between pathologists for PEC (rs = 0.88 and ICC = 0.91) and broadly similar to those for most other histologic features in the EoEHSS. The AI model also accurately identified PEC of >15 eosinophils/high-power field by the original pathologist (area under the curve [AUC] = 0.98) and central pathologist (AUC = 0.98) and had similar AUCs for the presence of EoE-related endoscopic features to pathologists' assessment. Average eosinophils per epithelial unit area had similar performance compared to AI high-power field-based analysis. Our newly developed AI model can accurately identify, quantify, and score several of the main histopathologic features in the EoE spectrum, with agreement regarding EoEHSS scoring which was similar to that seen among GI pathologists.

Food antigen consumption and disease activity affect food-specific IgG4 levels in patients with eosinophilic esophagitis (EoE).

INTRODUCTION: High levels of serum food-specific IgG4 (sIgG4) have been reported in patients with EoE. The objective of this study was to examine whether serum sIgG4 levels to foods and aeroallergens are higher in EoE patients than allergic controls and to investigate the association between sIgG4 and EoE clinical characteristics. METHODS: This was a case-control study nested in a prospective EoE Cohort. EoE cases were defined per consensus guidelines, and controls were individuals with symptoms who were confirmed to be EoE-negative on upper endoscopy. Demographic and clinical information was prospectively collected. Serum IgE and sIgG4 were measured to foods and aeroallergens by ImmunoCAP. Mean levels of sIgG4 were compared between cases and controls, and logistic regression models were used to examine predictors of elevated milk sIgG4 levels. RESULTS: The analysis included 123 individuals (EoE n = 93, control n = 30) with a similar distribution of allergic disease between EoE patients and controls (86% vs. 93%; p = .30). EoE patients had significantly higher sIgG4 levels to all allergens evaluated, with the exception of birch (p = .24). Milk sIgG4 levels were independently associated with milk consumption (OR 4.95; p = .01) and the presence of sIgE to milk (OR 4.23; p = .008). CONCLUSION: Serum sIgG4 levels to food and aeroallergen proteins were higher in patients with EoE than non-EoE controls, and higher levels of milk sIgG4 were independently associated with milk consumption and the presence of sIgE to milk proteins. Whether sIgG4 plays a pathogenic role in EoE or could be used as an EoE biomarker remains unknown and warrants further study.

Bulk T-cell receptor sequencing confirms clonality in pediatric eosinophilic esophagitis and identifies a food-specific repertoire.

BACKGROUND: Eosinophilic esophagitis (EoE) involves a chronic immune-mediated response to dietary antigens. Recent work identifies T-cell clonality in children with EoE, however, it is unknown whether this is true in adults or whether there is a restricted food-specific T-cell repertoire. We sought to confirm T-cell receptor (TCR) clonality in EoE and assess for differences with specific food triggers. METHODS: Bulk TCR sequencing was performed on mRNA isolated from esophageal biopsies obtained from adults and children with EoE (n = 15) who had food triggers confirmed by endoscopic evaluation. Non-EoE adult and pediatric controls (n = 10) were included. Differences in TCR clonality by disease and treatment status were assessed. Shared and similar V-J-CDR3s were assessed based on specific food triggers. RESULTS: Active EoE biopsies from children but not adults displayed decreased unique TCRα/ß clonotypes and increased relative abundance of TCRs comprising >1% of the total compared to non-EoE controls and paired inactive EoE samples. Among patients in which baseline, post diet elimination, and food trigger reintroduction samples (n = 6) were obtained, we observed ~1% of TCRs were shared only between pre-diet elimination and trigger reintroduction. Patients with a shared EoE trigger (milk) had a greater degree of shared and similar TCRs compared to patients with differing triggers (seafood, wheat, egg, soy). CONCLUSION: We confirmed relative clonality in children but not adults with active EoE and identified potential food-specific TCRs, particularly for milk-triggered EoE. Further studies are needed to better identify the broad TCR repertoire relevant to food triggers.

Food-induced immediate response of the esophagus in pediatric eosinophilic esophagitis.

BACKGROUND: Food-induced immediate response of the esophagus (FIRE) is a new phenomenon that has been described in eosinophilic esophagitis (EoE) patients. It is suspected when unpleasant symptoms occur suddenly on contact of the triggering food with the esophageal surface and recur with repeated exposures. It can often be mistaken for pollen-food allergy syndrome (PFAS) and solid food dysphagia. Data on FIRE is limited to one survey study and case reports, and there are no screening studies conducted on either adults or children with EoE. In this study, we aimed to screen children aged ≥7 years old with EoE for FIRE. METHODS: Demographic data were collected from medical records. A questionnaire about FIRE was applied to all participants. Skin prick tests were done on suspected patients to identify the triggering foods. FIRE is defined as suitable clinical symptoms with suspected food allergen exposure. RESULTS: A total of 78 patients (74.4% male, median age: 13.5 years) were included. Unpleasant and recurrent symptoms distinct from dysphagia with specific foods were reported in 16.7% of the patients, all of whom had concomitant allergic rhinitis (AR). The symptoms described by almost all patients were oropharyngeal itching and tingling (PFAS: 15.3%) excluding only one patient reporting retrosternal narrowing and pressure after specific food consumption (FIRE: 1.2%). CONCLUSIONS: Although definitive conclusions regarding the true prevalence of FIRE cannot be made, it does not seem to be common as PFAS. However, it deserves questioning particularly in the presence of concurrent AR and/or PFAS in children with EoE.

Food elimination diet is a viable alternative therapy for eosinophilic esophagitis responsive to proton pump inhibitors.

BACKGROUND: First-line treatment of eosinophilic esophagitis (EoE) includes monotherapy with proton-pump inhibitors (PPIs), food elimination diet (FED), or topical corticosteroids. Current guidelines suggest patients with EoE should continue any responsive first-line monotherapies. However, the efficacy of FED monotherapy in patients with EoE responsive to PPI monotherapy has not been well studied. Our study aimed to investigate how attempting FED monotherapy after experiencing remission of EoE after PPI monotherapy influenced long-term EoE management. METHODS: We retrospectively identified patients with EoE responsive to PPI monotherapy who trialed FED monotherapy. We then employed a mixed method approach to a prospective cohort. Selected patients were observed long term for quantitative outcomes, while qualitative results were obtained from patient surveys regarding their perspectives on the trial of FED monotherapy. RESULTS: We identified 22 patients who trialed FED monotherapy after experiencing remission of EoE following PPI monotherapy. Of these 22 patients, 13 had remission of EoE with FED monotherapy, while 9 had re-activation of EoE. Out of 22 patients, 15 were enrolled in a cohort for observation. No exacerbations of EoE occurred while on maintenance treatment. Most patients stated that they would recommend this process to others with EoE (93.33%) and that trial of FED monotherapy helped them identify a treatment plan that aligned with their lifestyle (80%). CONCLUSION: Our work shows that FED monotherapy can be an effective alternative for patients with EoE responsive to PPI monotherapy that may improve patient quality of life, suggesting alternative treatment options should be considered for monotherapy-responsive EoE.

Psychometric evaluation of the Spanish version of the Pediatric Quality of Life Eosinophilic Esophagitis Questionnaire (Peds QL-EoE Module ™).

BACKGROUND: The Paediatric Eosinophilic Oesophagitis Module (PedsQL-EoE) was developed in English as a valid and reliable questionnaire to assess health-related quality of life (HRQoL) in children with EoE. The aim of this study was to evaluate the validity and reliability of the PedsQL-EoE that was previously adapted to Spanish by our group. METHODS: This cross-sectional multicentre study was conducted in 36 paediatric gastroenterology units. Groups with and without dietary restrictions were studied separately. The PedsQL-EoE consists of 33 items divided into seven factors. Age-specific versions of the PedsQL-EoE were sent by e-mail to children and parents. Statistical analysis was used to study the questionnaire structure by means of exploratory factor analysis and interitem correlations. Confirmatory factor analysis (CFA) was applied to verify the proposed model as well as its psychometric properties through SMSR (standardized root mean square), outer loadings and R-square. To study construct validity and reliability, Cronbach´s alpha coefficient, convergent validity (AVE), discriminant validity (HTMT) and intraclass correlation coefficients (ICC) were used. RESULTS: A total of 341 children and 394 parents participated with 307 matched answers. The median age was 12 years, and 75% were male. The questionnaire structure explained 68% and 66% of the total variance for parents and children, respectively. Five items showed negative correlations and were removed from the questionnaire. CFA applied to the new model supported the following construct: SMRS was less than 0.08, outer loadings measured above 0.5, and R2 explained more than 89% of the total variance. Once the modifications were performed, good internal consistency was demonstrated, with Cronbach's alpha values > 0.7, AVE values > 0.5 and HTMT < 0.9 with good child/parent agreement (ICC = 0.80). The most robust model of the PedsQL-EoE module was formed by seven factors: Symptoms I (6 items), Symptoms II (4 items), Treatment (4 items), Worries (3 items), Communication (5 items), Food and Eating (3 items) and Food Feelings (3 items). CONCLUSIONS: The final PedsQL-EoE Module version, after the removal of five items, is a valid and reliable tool to be used in children with EoE. The Spanish validated version appears to be a useful instrument for measuring the impact of EoE on Spanish children´s quality of life.

Treatment of Pediatric Eosinophilic Esophagitis: Traditional and Novel Therapies.

PURPOSE OF REVIEW: This review presents and summarizes the existing studies on the treatment goals and options for pediatric eosinophilic esophagitis utilizing rigorous peer-reviewed literature. RECENT FINDINGS: In addition to traditional treatments, emerging biologic therapies continue to evolve the approach to treating pediatric eosinophilic esophagitis. Well defined treatment goals will aid the continued development of new therapies. Further, innovative assessment tools have changed how the clinician is able to assess the effectiveness of therapies with a trend toward less invasive options. The management of pediatric eosinophilic esophagitis continues to evolve with the advent of both novel treatment options and assessment tools. Treatment choices, with benefits and risks involved, should be presented to families upon diagnosis and tailored towards the individual patient and likelihood of adherence and success. Biologic therapy for EoE presents an exciting option for both first line therapy and escalation for those with severe or unresponsive disease.

Proton pump inhibitors in eosinophilic esophagitis (EoE) related to oral immunotherapy: is it as effective as in other EoE?

Oral immunotherapy (OIT) may induce eosinophilic esophagitis (EoE). Proton pump inhibitors (PPIs) are an effective treatment for EoE. However, the effect of PPI treatment is not well established in patients with EoE induced by OIT. Our primary aim was to compare the clinical, endoscopic, and histological response rates to PPIs in children with EoE induced by OIT (EoE+OIT) versus EoE patients without OIT (EoE-OIT). The secondary aims are to describe the clinical and histological features of EoE+OIT. Demographic, clinical, endoscopic, and histological findings of patients with EoE in the gastroenterology clinic at Shamir Medical Center between March 2015 and December 2022 were collected. Comparisons were performed between EoE+OIT and EoE-OIT patients. The study included 42 children (74% male, mean age 11.2), of whom 31 had EoE-OIT and 11 had EoE+OIT. There were no significant differences between groups regarding sex, comorbidities, symptoms, or endoscopic and histological characteristics at diagnosis. All 42 children were treated with PPIs after diagnosis with or without diet changes. The rates of any clinical response were 83.9% and 90.1% in the EoE-OIT group and EoE+OIT group, respectively (p = 1.0). The rate of any endoscopic response was 74.2% for EoE-OIT and 81.8% for EoE+OIT (p = 0.54). Histologically, PPIs were even more effective in the EoE+OIT group, where only 18.2% had no histological response at all compared to 51.6% in the EoE-OIT group (p = 0.1). CONCLUSION: PPI treatment is as effective in EoE with OIT as it is in EoE due to other etiologies. WHAT IS KNOWN: • Proton pump inhibitor (PPI) treatment is effective for achieving clinical response and histologic remission in some patients with eosinophilic esophagitis (EoE). • EoE has also been reported to be triggered by oral immunotherapy (OIT). WHAT IS NEW: • PPI treatment in EoE with OIT is as effective as treatment for EoE due to other etiologies.

Diagnostic merits of the Eosinophilic Esophagitis Diagnostic Panel from a single esophageal biopsy.

BACKGROUND: Eosinophilic esophagitis (EoE) is a histologically "patchy" disease with uneven eosinophil distribution along the esophagus, posing a dilemma for histologically analyzing endoscopic biopsy samples, especially when biopsy samples are limited to only the distal esophagus. OBJECTIVE: We investigated whether molecular mRNA profiling of a distal esophageal biopsy sample predicts eosinophilia in the proximal esophagus. METHODS: Esophageal biopsy samples (n = 507) from subjects with EoE were collected from multiple institutions, spanning adults and pediatric patients. Subjects were grouped on the basis of distinct distal (D) and proximal (P) eosinophil counts (D+P+, D+P-, D-P+, and D-P-, with + and - defined as ≥15 or <15 eosinophils/hpf, respectively). Molecular profiles were assessed by using the EoE Diagnostic Panel (EDP), a set of 96 esophageal transcripts used to derive the EDP score. RESULTS: The distal EDP score was correlated with proximal eosinophil levels (r = -0.73; P < .0001). EDP analysis of a histologically negative distal biopsy sample predicted the presence of proximal esophagitis with high sensitivity (85%). In a 2-year follow-up focusing on the cases with discordant histologic and EDP results, histologically negative patients (D-P-) had higher rates of EoE relapse when the EDP was positive than when the EDP was negative (odds ratio = 11; P = .003), indicating predictive medicine capacity. CONCLUSION: EDP analysis of a single distal esophageal biopsy sample predicts remote inflammation in patients with spatially heterogeneous eosinophilia and disease relapse in patients with histologic remission, providing diagnostic merit and predictive medicine capacity for molecular diagnosis of EoE.

A Single-Food Milk Elimination Diet Is Effective for Treatment of Eosinophilic Esophagitis in Children.

BACKGROUND & AIMS: Cow's milk protein (CMP) is the most common trigger of inflammation in children and adults with eosinophilic esophagitis (EoE). We sought to assess the clinical, endoscopic, and histologic efficacy of dietary elimination of all CMP-containing foods in EoE. METHODS: We performed a prospective observational study in children with EoE treated with the 1-food elimination diet (1FED), excluding all CMP. Children and their caretakers were educated by a registered dietitian regarding dietary elimination of all CMP-containing foods, with substitutions to meet nutritional needs for optimal growth and development, and daily meal planning. Upper endoscopy with biopsies was performed after 8 to 12 weeks of treatment. The primary end point was histologic remission, defined as fewer than 15 eosinophils per high-power field. Secondary end points were symptomatic, endoscopic, and quality-of-life (QOL) improvements. RESULTS: Forty-one children (76% male; ages, 9 ± 4 years; 88% white) underwent 1FED education and post-treatment endoscopy with biopsies. Histologic remission occurred in 21 (51%) children, with a decrease in peak eosinophils per high-power field from a median of 50 (interquartile range, 35-70) to a median of 1 (interquartile range, 0-6; P < .0001). Endoscopic abnormalities improved in 24 (59%) patients, while symptoms improved in 25 (61%). Improved symptoms included chest pain, dysphagia, and pocketing/spitting out food. Parents perceived worse QOL, while children perceived improved QOL with the 1FED. CONCLUSIONS: One-food elimination of CMP-containing foods from the diet induced histologic remission in more than 50% of children with EoE and led to significant improvement in symptoms and endoscopic abnormalities. The ease of implementation and adherence supports the 1FED as first-line dietary treatment.

Eosinophilic esophagitis: A review of the pediatric population and consideration of upcoming therapies.

Eosinophilic esophagitis (EoE) is a disease entity that has become increasingly recognized in the pediatric population over the last decade and was first recognized as early as 1990. EoE is a clinicopathologic diagnosis with signs and symptoms varying between age groups. The clinical presentation of EoE is variable ranging from milder nonspecific symptoms, such as abdominal pain, vomiting, and dyspepsia, to more severe presentations such as failure to thrive, dysphagia and even food impaction and is dependent on age of diagnosis 2. There is growing body of evidence with regards to the pathophysiology, diagnostic modalities, and treatment options for EoE in the past decade. In this review article, we aim to discuss the disease burden, pathophysiology, diagnostic strategies, and currently available treatment options for EoE based on existing literature.

Simultaneous Examination of Eosinophil Infiltration in Esophageal Mucosa and Muscle in Patients with Achalasia: Direct Biopsy of the Esophageal Muscle at Per-oral Endoscopic Myotomy.

BACKGROUND: The relationship between eosinophilic esophagitis (EoE) and achalasia is not completely understood. There have been reports of eosinophilic infiltration of all esophageal layers in patients with achalasia. However, a routine endoscopic biopsy of the muscular layer is usually not feasible. We evaluate the safety and efficacy of muscle layer biopsy during per-oral endoscopic myotomy (POEM) as well as the prevalence of eosinophilic infiltration of the esophageal mucosa and muscular layer in patients with achalasia. PATIENTS AND METHODS: All enrolled patients had diagnosed achalasia and had simultaneous biopsies of the muscular layer at the middle esophagus and distal esophageal sphincter as well as the mucosal layer of the proximal and distal esophagus during POEM. All POEM procedures took place from August 2018 to December 2018 or September 2019 to November 2019. Various demographic, disease-related, and procedure-related data were collected from chart review. Eosinophilic infiltration in the biopsy specimen was examined. KEY RESULTS: Twenty consecutive patients (65% female, age range: 21-84) with a pre-procedure Eckardt score of >6 were enrolled during the study period, with the duration of their achalasia ranging from 1 to 32 years. Eighteen patients had clinical symptomatic improvement after POEM, as defined by an Eckardt score <3. Endoscopic examination did not reveal any signs of eosinophilic esophagitis. Pathologic examination of biopsies revealed eosinophilic infiltration in three of 20 patients (15%) in the distal esophageal mucosa (all <15 eosinophils/HPF) and none in the proximal esophageal mucosa. There was no eosinophilic infiltration in the distal esophageal sphincter and the middle esophageal muscle. No complication was noted due to muscle biopsy. CONCLUSIONS AND INFERENCES: Submucosal tunneling during POEM provides a safe access for direct esophageal muscle biopsy. This is the first report of the simultaneous biopsy of the esophageal mucosa and muscle in patients with achalasia. Contrary to all previously published studies, the association of esophageal eosinophilic infiltration and achalasia was not observed in this small sample study. Based on our findings, immune or autoimmune reaction rather than direct eosinophilic infiltration in the muscle is more likely the cause of achalasia.

Needs Assessment for Eosinophilic Esophagitis Education in School Nurses.

Over the past 2 decades, eosinophilic esophagitis (EoE) has become increasingly recognized as a common cause of gastrointestinal morbidity in children. A mainstay of treatment is food avoidance, which must be implemented in both the home and school settings for school-aged children. The aim of this study is to assess school nurses' familiarity with EoE with regard to food avoidance and treatment in the school setting. We conducted a 19-question online survey of 60 school nurses (elementary through high school) recruited from Dauphin, Lebanon, and Lancaster Counties in Pennsylvania. Results indicated that 62% of respondents were familiar with EoE. However, only 22% felt comfortable distinguishing between symptoms of EoE and food-dependent anaphylaxis. Almost all respondents (97%) were interested in learning more about EoE. We report significantly increased familiarity with food-dependent anaphylaxis in comparison with EoE among school nurses. There is an interest and need for increasing education on EoE.

Tacrolimus (FK506) treatment protects allergen-, IL-5- and IL-13-induced mucosal eosinophilia.

Eosinophils are a common clinical feature associated with chronic allergic diseases, and elemental diets, systemic steroids, anti-IL-5 and anti-IL-13 treatment have shown some therapeutic promise. Herein, we present evidence that pre- and post-intraperitoneal administration of tacrolimus (FK506) is very effective in reducing CCR3/Siglec-F+ eosinophils in Aspergillus-challenged asthma and EoE, CD2-IL-5 induced global eosinophilia, and DOX regulated IL-13-induced asthma. We used flow cytometry and anti-major basic protein (MBP) immunostaining to examine eosinophils in the spleen, bone marrow, BALF, lung, oesophagus and intestine. Additionally, we also performed ELISA and Western blot analyses to show that tacrolimus treatment also reduces the levels of eosinophil-specific cytokines IL-4, IL-5, IL-13 and TGF-ß, eosinophil-specific chemokines Eotaxin-1 and Eotaxin-2, and progenitors of target RCAN1 mRNA and protein levels. Additionally, the current investigations also show that the TGF-ß-mediated oesophageal and lung fibrosis is also reduced in Aspergillus-challenged, CD2-IL-5 transgenic and DOX-responsive IL-13 mice. Mechanistically, we show that tacrolimus in vitro treatment inhibited bone marrow-derived eosinophil proliferation and viability by promoting eosinophil apoptosis that may be associated with downregulation of RCAN1. Taken together, we provide in vivo and in vitro evidence that tacrolimus ameliorates eosinophil levels and associated pathogenesis in allergen-, IL-5- and IL-13-induced EoE, EG and asthma pathogenesis. Considering tacrolimus side-effects and reactivity to several other drugs, we propose the topical use of tacrolimus for paediatric and low-dose oral for adult patients as a novel therapeutic strategy for the clinical trial to reduce mucosal eosinophilia first in steroid-refractory or elemental diet non-responsive adult EoE, EG and asthma patients.

Blood mRNA levels of T cells and IgE receptors are novel non-invasive biomarkers for eosinophilic esophagitis (EoE).

Eosinophilic esophagitis (EoE) is often misdiagnosed as GERD; therefore, the goal of the current study is to establish a non-invasive diagnostic and monitoring biomarker that differentiated GERD from EoE. Reports indicates that IL-15 responsive iNKT cells and tissue specific IgE have a critical in EoE pathogenesis, not in GERD. Therefore, we tested the hypothesis that the panel of IL-15-responsive T cell and IgE receptors may be novel non-invasive biomarkers for EoE. Accordingly, the receptors of IL-15 responsive T cells (Vα24, Jα18, γδT, αßT) and IgE (FcεRI & FcεRII) were examined. The data indicates that blood mRNA levels of Vα24, Jα18, γδ T, αß T and FcεRI are significantly reduced in EoE compared to the GERD patients and normal individuals. The ROC curve analysis indicated FcεRII, Jα18 and δ TCR are the positive predictors that discriminate EoE from GERD. Thus, these molecules will be a novel non-invasive diagnostic biomarker for EoE.