Eosinophilic Esophagitis: Pathophysiology and Definition

Eosinophilic esophagitis: Current concepts in diagnosis and management

ABSTRACT

Eosinophilic esophagitis is an antigen-mediated chronic inflammatory disorder that has risen in incidence and prevalence over the past 2 decades. The clinical presentation is variable and consists of mainly esophageal symptoms such as dysphagia, heartburn, food impaction, and vomiting. Current management relies on dietary elimination, proton-pump inhibitors, and topical corticosteroids with different response rates and relapses after treatment discontinuation. With a better understanding of the underlying pathophysiology, many molecules emerged recently as targeted treatment including dupilumab (IL4/IL13 blocker), as the first FDA-approved biological treatment, which has changed the management paradigm.

The Cellie Coping Kit for children with Eosinophilic Esophagitis: Feasibility, acceptability, and preliminary outcomes

Children with eosinophilic esophagitis (EoE) are faced with ongoing treatments that can impact their wellbeing. There are no evidence-based resources that families can implement independently to cope with EoE-related stressors. This study aimed to examine acceptability, feasibility, and preliminary outcomes of the newly developed Cellie Coping Kit for Children with EoE intervention. Forty child-caregiver dyads completed a baseline assessment (T1) and initiated the intervention; 30 (75%) child participants and 33 (82.5%) caregivers were retained to follow-up (T2). Of those who completed the T2 assessment, most reported that the intervention was easy to use (>90%) and would recommend the intervention to others (>90%). The intervention was feasible: >70% used the kit, and most indicated they would use it again (>75%). More than half of families reported learning new information and/or coping strategies. No statistically significant changes were identified in comparing T1 and T2 coping and health-related quality of life. These findings suggest that the Cellie Coping Kit for Children with EoE is a promising intervention in that it was well accepted, feasible, and helped many families learn novel strategies on how to manage EoE challenges. Future research should examine how to strengthen the intervention to achieve longer-term targeted outcomes.

New Indications of Biological Drugs in Allergic and Immunological Disorders: Beyond Asthma, Urticaria, and Atopic Dermatitis

Asthma, chronic urticaria, and atopic dermatitis are some of the most numerous allergic diseases affecting children. Recent advances in the understanding of their specific intracellular molecular pathways have led to the approval of monoclonal antibodies targeting definite inflammatory molecules in order to control symptoms and improve quality of life. Less is known about other allergic and immunologic disorders such as rhinosinusitis with nasal polyps, eosinophilic esophagitis, anaphylaxis, and food allergy undergoing allergen immunotherapy. The increasing evidence of the molecular mechanisms underlying their pathogeneses made it possible to find in children new indications for known biological drugs, such as omalizumab and dupilumab, and to develop other ones even more specific. Promising results were recently obtained, although few are currently approved in the pediatric population. In this review, we aim to provide the latest evidence about the role, safety, and efficacy of biologic agents to treat allergic and immunologic diseases in children.

Nonatopic Eosinophilic Esophagitis in an Adult

Eosinophilic esophagitis (EoE) is an inflammatory condition limited to the esophagus, predominantly consisting of eosinophils, and triggered by hypersensitivity reactions. Recurrent dysphagia secondary to EoE is uncommon in patients with no history of asthma and/or atopic conditions. We are presenting a case of a 48-year-old male suffering from dysphagia for 10 years that worsened over a six-month period. The patient reported no known food and drug allergies, asthma, and other atopic conditions. On esophagogastroduodenoscopy (EGD), the patient fulfilled all five endoscopic reference score (EREFS) criteria, granting a final diagnosis of eosinophilic esophagitis with a score of 6. Biopsy confirmed eosinophilic esophagitis, revealing 20 eosinophils/high-power fields. Skin prick testing was negative. His symptoms had improved at the office follow-up after three weeks after esophageal dilation and proton pump inhibitor (PPI) but did not completely resolve. The patient was then started on fluticasone 440 mcg two times a day. After eight weeks, the patient was symptom-free by taking dual therapy of PPI and fluticasone. The patient was advised to continue taking the daily PPI and then a six-week course of fluticasone if he experienced an exacerbation in his symptoms. In this report, symptom improvement with esophageal dilation, PPI, and fluticasone suggested a successful treatment regimen for EoE in the setting of no known atopy in our patient. Our case highlights EoE in an adult with no known asthma and allergies. The report identifies the importance of a prompt clinical diagnosis and appropriate combination treatment due to the progressive pain and its worsening associated with eosinophilic esophagitis.

Induction of Severe Eosinophilic Esophagitis and Multi-Organ Inflammation by Airborne Allergens is Associated with IL-4/IL-13 and CCL11 but Not IgE in Genetic Susceptible Mice

Background

Eosinophilic Esophagitis (EoE) is an increasingly common chronic inflammatory disease. The pathological mechanisms underlying EoE are largely unknown.

Objective

We sought to understand the mechanisms underlying aeroallergen-induced EoE in Sharpin gene deficient (Sharpin-/-) mice that is prone to inflammatory response.

Methods

Sharpin-/-mice were exposed with Aspergillus fumigatus and ovalbumin intranasally every alternate day for 4 weeks. Wild type (WT) naïve mice, WT exposed, and un-exposed Sharpin-/- mice were controls. Histopathological analysis was performed by H&E, trichrome and major basic protein staining. Total and specific IgE, IgG, and IgA levels were measured by ELISA and Th2 cytokine and CCL11 chemokine gene expression were determined.

Results

Airborne allergen exposed Sharpin-/- mice showed severe eosinophilic inflammation in the esophagus (p < 0.001), and markedly increased epithelial thickening (p < 0.0001) compared to WT normal controls, whereas airborne allergen exposed WT mice and unexposed Sharpin-/- mice only showed mild eosinophilic inflammation in the esophagus. These exposed Sharpin-/- mice also showed over 7-fold increase in blood eosinophils (p < 0.0001), 60-fold increase in eosinophils in bronchoalveolar lavage fluid (p < 0.0001) and 4-fold increase in eosinophils in the skin (p < 0.0001) compared to normal controls. Surprisingly, exposed Sharpin-/- mice did not show elevation of serum total or antigen-specific IgE levels but reduced total IgA and IgG levels than normal controls There was a marked increase in IL-4, IL-13 and CCL11 gene expression in esophageal tissue (p < 0.001) in exposed Sharpin-/- mice compared to WT normal mice.

Conclusion

Th2 cytokines and chemokines, but not IgE may play an important pathologic role in aeroallergen-induced EoE. This study may provide insight into new therapeutics for EoE.

Gene expression and clinical outcomes after dietary treatment for eosinophilic esophagitis: a prospective study

BACKGROUND

Eosinophilic esophagitis (EoE) is an allergen-mediated disease and elimination diets have proven to be effective to obtain clinical and histological remission. However, the effect of elimination diets on specific EoE transcripts and their clinical correlates is relatively unknown. The main aim of the study was to evaluate the effect of dietary treatment (four-food elimination diet [FFED]) with or without addition of amino acid-based formula (AAF) on a variety of pro-/anti-inflammatory, epithelial/barrier function and remodeling/fibrosis-related markers of disease activity and clinical correlates (eosinophils, symptoms, and endoscopic signs) in adult EoE patients.

METHODS

We conducted an analysis of biopsy samples and data collected during a randomized controlled trial with an elimination diet in adult patients with active EoE (≥15 eosinophils [eos] per high-power field [hpf]). Demographics, symptoms (SDI-score), endoscopic signs (EREFS) and peak eosinophil counts/hpf were recorded at baseline and after 6 weeks of treatment. Transcripts of 10 indicated genes were measured (qPCR) and compared to clinical correlates at baseline and after treatment.

KEY RESULTS

Forty patients (pooled FFED + FFED + AAF) (60% male, age 34.5 (interquartile range [IQR] 29-42.8 years) completed the diet. Peak eosinophil counts/hpf, symptoms and endoscopic signs were significantly decreased after 6 weeks dietary treatment. DSG-1 levels were significantly upregulated from baseline to week 6, whereas IL-13, CAPN-14, IL-5, IL-10, CCL-26, POSTN, TSLP, CPA-3, and TGF-β were significantly downregulated after 6 weeks of diet (all; <0.01). Prior to treatment, upregulation of CAPN-14 and lower levels of DSG-1 were associated with clinical fibrotic phenotypes, whereas upregulation of IL-10 was linked to food impaction phenotypes.

CONCLUSION

These findings strongly suggest that elimination diets, besides a clinical and histological response, are associated with a broad transcriptional response at the level of the esophageal epithelium.

Eosinophilic Disorders of the Gastrointestinal Tract and Associated Abdominal Viscera: Imaging Findings and Diagnosis

Eosinophilic gastrointestinal disorders (EGIDs) are inflammatory conditions of the gastrointestinal tract that are characterized by tissue eosinophilia and end-organ dysfunction or damage. Primary EGIDs are associated with atopy and other allergic conditions, whereas secondary EGIDs are associated with underlying systemic diseases or hypereosinophilic syndrome. Within the spectrum of EGIDs, eosinophilic esophagitis is the most prevalent. Eosinophilic gastroenteritis and eosinophilic colitis are relatively uncommon. Eosinophilic infiltration of the liver, biliary tree, and/or pancreas also can occur and mimic other inflammatory and malignant conditions. Although endoscopic evaluation is the method of choice for eosinophilic esophagitis, radiologic evaluation of the esophagus plays an important role in the assessment of disease severity. CT and MR enterography are the modalities of choice for demonstrating specific forms of eosinophilic gastroenteritis. CT and MRI are important in the detection of abdominal visceral involvement in EGIDs. Diagnosis is often challenging and relies on symptoms, imaging findings, histologic confirmation of tissue eosinophilia, and correlation with peripheral eosinophilia. Imaging is crucial for identifying characteristic organ-specific findings, although imaging findings are not specific. When promptly treated, EGIDs usually have a benign clinical course. However, a delayed diagnosis and associated surgical interventions have been associated with morbidity. Therefore, a radiologist's knowledge of the imaging findings of EGIDs in the appropriate clinical settings may aid in early diagnosis and thereby improve patient care. An overview of the clinical features and imaging findings of EGIDs and the eosinophilic disorders of associated abdominal viscera is provided. Online supplemental material is available for this article. ^©RSNA, 2022.

Clinicopathological Differences between Eosinophilic Esophagitis and Asymptomatic Esophageal Eosinophilia

Objective According to consensus guidelines, eosinophilic esophagitis (EoE) is defined as a clinicopathological entity whose symptoms and histology must always be considered together. However, endoscopic findings typical of EoE are often seen in asymptomatic esophageal eosinophilia (aEE). We aimed to clarify the clinicopathological features of aEE. Methods We retrospectively compared cases of aEE and those of symptomatic EoE. Materials We reviewed 146 patients who underwent upper gastrointestinal endoscopy and were confirmed histopathologically to have esophageal eosinophil infiltration of at least 15 eosinophils per high-power field. They were divided into the aEE group (n=75) and the EoE group (n=71). Patients' clinicopathological findings were then collected and examined. Results The EoE group experienced dysphagia (47.9%), heartburn (40.8%), food impaction (40.8%), chest pain (16.9%), and other symptoms (8.5%). There was no significant difference between the two groups with regard to age, sex, current smoking status, or alcohol consumption. The aEE group had a significantly higher body mass index (p<0.01) and significantly lower frequency of concurrent allergic diseases (p<0.01) than the EoE group. No significant differences were found between the two groups with regard to the mean peripheral blood eosinophil count, non-specific immunoglobulin E concentration, peak eosinophil infiltration in the biopsy specimens, EoE histology scoring system, phenotype and location of typical endoscopic findings of EoE, or thickness of the esophagus wall or the mucosal and submucosal layer as measured by endoscopic ultrasonography. Two patients in the aEE group who were followed up without treatment subsequently developed esophageal symptoms. Conclusion aEE and EoE may have the same clinicopathological features.

Eosinophilic Esophagitis and IgG4: Is There a Relationship?

Our knowledge of the pathophysiology of eosinophilic esophagitis is constantly evolving. There is significant association between eosinophilic esophagitis and atopy; however, multiple studies have refuted the role of IgE in its pathogenesis. Instead, new data have demonstrated an elevated IgG4 level in patients with eosinophilic esophagitis. We review the current understanding of eosinophilic esophagitis pathogenesis and highlight the increasing evidence for the role of IgG4.

Pediatric eosinophilic esophagitis: a review for the clinician

Eosinophilic esophagitis (EoE) is a chronic clinical-pathologic disease characterized by eosinophilic infiltration of the esophageal epithelium with esophageal dysfunction symptoms.EoE can occur at any age and has different clinical manifestations depending on the age onset.To date, esophago-gastroduodenal endoscopy (EGD) with biopsy is the gold-standard for EoE diagnosis.According to the recent consensus guidelines, proton pump inhibitors, corticosteroids and elimination diets could be a first-line therapy option. The aim of the treatment is clinical and histological remission for preventing long-lasting untreatable fibrosis.A multidisciplinary approach (allergist, gastroenterology, dietitian, and pathologist) is recommended for managing patients affected by EoE, given the complexity of its treatment.This review will provide a practical guide to assist pediatricians treating children with EoE.Moreover, it highlights the unmet needs in diagnosis and treatment that require urgent attention from the scientific community in the aim of improving the management of patients with EoE.

Association of eosinophil-mediated inflammatory biomarkers with the presence of the Schatzki ring

PURPOSE

The study aimed to assess the level of inflammatory biomarkers related to eosinophilia: interleukins 5 (IL-5) and 13 (IL-13), eotaxin 3, major basic protein (MBP) and transforming growth factor β1 (TGF-β1) in patients with dysphagia and Schatzki ring (SR), as well as the characteristics of this group of patients in terms of the features differentiating gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EoE).

PATIENTS AND METHODS

We analyzed 42 patients with dysphagia, each of whom underwent panendoscopy with an assessment of the occurrence of SR, retrospectively assessed EoE Endoscopic Reference Score (EREFS) total, inflammatory and fibrostenotic and serum concentrations of IL-5 and 13, TGF-β1, eotaxin 3 and MBP. All of them completed a symptom and comorbid questionnaire. Patients diagnosed with SR constituted the SR group (n ​= ​8), the rest - the non-SR group. The quantification of the biomarkers was performed by enzyme immunoassay (ELISA). In the data analysis, p ​≤ ​0.05 was considered statistically significant.

RESULTS

We demonstrated a significant increase in terms of exceeding the reference values of TGF-β1 (37.5% vs 8.8%) and MBP (75% vs 35.3%) in patients with SR compared to the non-SR group (qualitative analysis). There was also a statistically significant increase in the concentration of each of the determined biomarkers (quantitative analysis) in the SR group.

CONCLUSIONS

The increase in TGF-β1 and MBP concentrations indicates the inflammatory and probably fibrostenotic pathogenesis of SR. Obtained results do not allow for an unequivocal classification of SR as a complication typical only for GERD or EoE.

Eosinophils in Eosinophilic Esophagitis: The Road to Fibrostenosis is Paved With Good Intentions

Eosinophilic esophagitis (EoE) is an antigen-driven disease associated with epithelial barrier dysfunction and chronic type 2 inflammation. Eosinophils are the defining feature of EoE histopathology but relatively little is known about their role in disease onset and progression. Classically defined as destructive, end-stage effector cells, eosinophils (a resident leukocyte in most of the GI tract) are increasingly understood to play roles in local immunity, tissue homeostasis, remodeling, and repair. Indeed, asymptomatic esophageal eosinophilia is observed in IgE-mediated food allergy. Interestingly, EoE is a potential complication of oral immunotherapy (OIT) for food allergy. However, we recently found that patients with peanut allergy may have asymptomatic esophageal eosinophilia at baseline and that peanut OIT induces transient esophageal eosinophilia in most subjects. This is seemingly at odds with multiple studies which have shown that EoE disease severity correlates with tissue eosinophilia. Herein, we review the potential role of eosinophils in EoE at different stages of disease pathogenesis. Based on current literature we suggest the following: (1) eosinophils are recruited to the esophagus as a homeostatic response to epithelial barrier disruption; (2) eosinophils mediate barrier-protective activities including local antibody production, mucus production and epithelial turnover; and (3) when type 2 inflammation persists, eosinophils promote fibrosis.

Effectiveness of allergy testing in milk induced eosinophilic esophagitis. Description and follow-up of patients

INTRODUCTION

Eosinophilic esophagitis (EoE) is a chronic, local immune-mediated esophageal disease that has been on the increase lately. There is currently enough evidence to conclude that EoE is an allergic disorder triggered by food allergens, with cow's milk (CM) being the most frequent. Dietary intervention is the first-line approach. This study aimed to assess the clinical characteristics, the diagnostic method, and the prognosis of patients whose culprit food was CM, as opposed to other triggers.

METHODS

Children with EoE evaluated in our pediatric Allergy Department were retrospectively studied from 2004 to 2017. We collected clinical variables, diagnostic protocol, treatment, and follow-up data. We compared patients whose culprit food was CM and patients with EoE due to other causative agents.

RESULTS

We analyzed 31 children with EoE and found the causative food to be cow's milk in 14 (45%). Clinical characteristics were similar in patients with EoE due to milk or any other cause. Eight of 14 patients with milk-induced EoE (57.14%) presented positive skin prick test results against cow's milk. All patients had positive IgE against cow's milk. None of the patients had any other food as the trigger. The median follow-up was 2.68 years (6 months to 9 years) with initial remission of 100%.

CONCLUSION

Testing-based elimination diets effectively treated all of the patients with milk-induced EoE. The advantage of this diagnostic protocol is that it required a mean of only two foods to be tested, significantly smaller number than in empiric diets.

Pathogenesis of Eosinophilic Esophagitis: A Comprehensive Review of the Genetic and Molecular Aspects

Eosinophilic esophagitis (EoE) is a relatively new condition described as an allergic-mediated disease of the esophagus. Clinically, it is characterized by dysphagia, food impaction, and reflux-like symptoms. Multiple genome-wide association studies (GWAS) have been conducted to identify genetic loci associated with EoE. The integration of numerous studies investigating the genetic polymorphisms in EoE and the Mendelian diseases associated with EoE are discussed to provide insights into the genetic risk of EoE, notably focusing on CCL26 and CAPN14. We focus on the genetic loci investigated thus far, and their classification according to whether the function near the loci is known. The pathophysiology of EoE is described by separately presenting the known function of each cell and molecule, with the major contributors being eosinophils, Th2 cells, thymic stromal lymphopoietin (TSLP), transforming growth factor (TGF)-β1, and interleukin (IL)-13. This review aims to provide detailed descriptions of the genetics and the comprehensive pathophysiology of EoE.

Management of Eosinophilic Esophagitis: Dietary and Nondietary Approaches

Eosinophilic esophagitis (EoE) is an allergen-driven chronic inflammatory condition, characterized by symptoms related to esophageal dysfunction and confirmed histologically by esophageal mucosal eosinophilia. Since its first description in the 1990s, the incidence and prevalence of EoE have been on the rise. It is known to affect all ages of various ethnic backgrounds and both sexes; however, it is most seen in White males. Children with EoE often present with abdominal pain, nausea, vomiting, and failure to thrive, whereas adults with EoE typically present with dysphagia and food impaction. Diagnosis of EoE requires histologic confirmation of elevated esophageal eosinophils in a symptomatic patient, and only after secondary causes have been excluded. Because EoE is a chronic and progressively fibrostenotic disease, treatment goals include resolution of symptoms, induction and maintenance of disease remission, and prevention and possibly reversal of fibrostenotic complications, while minimizing treatment-related adverse effects and improving quality of life. Treatment strategies include the "3 D's"-drugs, diet, and dilation. Standard drug therapies include proton-pump inhibitors and topical corticosteroids. Dietary therapies include elemental diet, allergy testing-directed elimination diet, and empiric elimination diets. Endoscopic esophageal dilation for EoE strictures can alleviate esophageal symptoms but has no effect on mucosal inflammation. Recent progress in EoE research has made possible evidence-based clinical guidelines. Ongoing pharmacologic trials show promise for novel biologic agents in the treatment of refractory EoE.

Challenges and updates in the management of eosinophilic esophagitis

Eosinophilic esophagitis (EE) is a chronic T helper cell-2 mediated inflammatory condition and is considered as a primary cause of dysphagia and foregut symptoms. There are many challenges regarding the treatment options of EE. Different therapeutic approaches are best at meeting different endpoints. There are unresolved questions such as whether the goal for treatment should be to control esophageal eosinophilia and inflammation or to achieve symptomatic improvement. Still, proton pump inhibitors are used in differential diagnosis, along with their anti-inflammatory and anti-acid properties. Conducted trials continue to recommend the use of topical corticosteroids and empiric food elimination diets as first-line therapeutic modalities. The growing knowledge on the pathogenesis of EE has allowed further progression of encouraging targeted biologic therapies. However, the guidelines for EE management should be updated accordingly in the coming years, including fast evolving data on non-invasive diagnostic strategies, new treatment modalities, and the long-term prognosis of the disease.

Eosinophilic esophagitis: Current concepts in diagnosis and treatment

Eosinophilic esophagitis is an immune-allergic pathology of multifactorial etiology (genetic and environmental) that affects both pediatric and adult patients. Its symptoms, which include heartburn, regurgitation, and esophageal stenosis (with dysphagia being more frequent in eosinophilic esophagitis in young adults and children), are similar to those of gastroesophageal reflux disease, causing delays in diagnosis and treatment. Although endoscopic findings such as furrows, esophageal mucosa trachealization, and whitish exudates may suggest its presence, this diagnosis should be confirmed histologically based on the presence of more than 15 eosinophils per high-power field and the exclusion of other causes of eosinophilia (parasitic infections, hypereosinophilic syndrome, inflammatory bowel disease, among others) for which treatment could be initiated. Currently, the 3 “D”s (“Drugs, Diet, and Dilation”) are considered the fundamental components of treatment. The first 2 components, which involve the use of proton pump inhibitors, corticosteroids, immunosuppressants and empirical diets or guided food elimination based on allergy tests, are more useful in the initial phases, whereas endoscopic dilation is reserved for esophageal strictures. Herein, the most important aspects of eosinophilic esophagitis pathophysiology will be reviewed, in addition to evidence for the various treatments.

A Case of Eosinophilic Esophagitis Associated with Herpes Esophagitis in a Pediatric Patient

Eosinophilic esophagitis is a rare disease in Asian countries, but its incidence is growing rapidly in Western countries. The main pathophysiology of eosinophilic esophagitis is esophageal epithelial barrier dysfunction; disruption of the esophageal epithelial barrier easily induces antigen sensitization to foods and aeroallergens, which leads to subsequent esophageal inflammation as a result of eosinophil recruitment. Here we report a case of an 11-year-old Korean boy who suffered from fever, odynophagia, dysphagia, and chest pain. His upper endoscopic findings showed longitudinal ulcers with a volcano-like appearance at the distal esophagus. Polymerase chain reaction test results and biopsy specimens were positive for herpes simplex virus type 1. He was treated with acyclovir and a proton pump inhibitor, but his follow-up endoscopy showed typical patterns of eosinophilic esophagitis, and the biopsy specimens were compatible with the diagnostic criteria for eosinophilic esophagitis. Therefore, we report a very rare case of eosinophilic esophagitis after herpes esophagitis in a Korean child with normal immunity.

Pediatric eosinophilic esophagitis: updates for the primary care setting

PURPOSE OF REVIEW

Eosinophilic esophagitis (EoE) is a multifactorial, non-IgE-mediated inflammatory disorder of the esophagus and is the most common cause of food impaction in the pediatric population. The purpose of this review is to describe the current recommendations for diagnosis and management of EoE.

RECENT FINDINGS

New data has associated EoE with other allergic disorders of the atopic march as well as several risk factors, which predispose to allergic conditions. A subset of patients with esophageal eosinophilia respond to proton pump inhibitor (PPI) therapy with a partial or complete resolution of esophageal eosinophilia. Therefore, some patients can be treated with PPI alone. If this is unsuccessful, dietary elimination and swallowed steroid therapy are recommended for long-term management. There is a growing appreciation that untreated esophageal inflammation can lead to complications of fibrosis and stricture formation.

SUMMARY

The current review will focus on the diagnosis and management of EoE in the pediatric population. Identification and diagnosis of pediatric patients with EoE is critical to prevent long-term esophageal complications.

A Distinct Esophageal mRNA Pattern Identifies Eosinophilic Esophagitis Patients With Food Impactions

Eosinophilic esophagitis (EoE), a Th2-type allergic immune disorder characterized by an eosinophil-rich esophageal immune infiltrate, is often associated with food impaction (FI) in pediatric patients but the molecular mechanisms underlying the development of this complication are not well understood. We aim to identify molecular pathways involved in the development of FI. Due to large variations in disease presentation, our analysis was further geared to find markers capable of distinguishing EoE patients that are prone to develop food impactions and thus expand an established medical algorithm for EoE by developing a secondary analysis that allows for the identification of patients with food impactions as a distinct patient population. To this end, mRNA patterns from esophageal biopsies of pediatric EoE patients presenting with and without food impactions were compared and machine learning techniques were employed to establish a diagnostic probability score to identify patients with food impactions (EoE+FI). Our analysis showed that EoE patients with food impaction were indistinguishable from other EoE patients based on their tissue eosinophil count, serum IgE levels, or the mRNA transcriptome-based p(EoE). Irrespectively, an additional analysis loop of the medical algorithm was able to separate EoE+FI patients and a composite FI-score was established that identified such patients with a sensitivity of 93% and a specificity of 100%. The esophageal mRNA pattern of EoE+FI patients was typified by lower expression levels of mast cell markers and Th2 associated transcripts, such as FCERIB, CPA3, CCL2, IL4, and IL5. Furthermore, lower expression levels of regulators of esophageal motility (NOS2 and HIF1A) were detected in EoE+FI. The EoE+FI -specific mRNA pattern indicates that impaired motility may be one underlying factor for the development of food impactions in pediatric patients. The availability of improved diagnostic tools such as a medical algorithm for EoE subpopulations will have a direct impact on clinical practice because such strategies can identify molecular inflammatory characteristics of individual EoE patients, which, in turn, will facilitate the development of individualized therapeutic approaches that target the relevant pathways affected in each patient.

Eosinophilic Esophagitis: Review and Update

Background: Eosinophilic esophagitis (EoE) was first described in the 1990s, showing an increasing incidence and prevalence since then, being the leading cause of food impaction and the major cause of dysphagia. Probably, in a few years, EoE may no longer be considered a rare disease. Methods: This article discusses new aspects of the pathogenesis, symptoms, diagnosis, and treatment of EoE according to the last published guidelines. Results: The epidemiological studies indicate a multifactorial origin for EoE, where environmental and genetic factors take part. EoE affects both children and adults and it is frequently associated with atopic disease and IgE-mediated food allergies. In patients undergoing oral immunotherapy for desensitization from IgE-mediated food allergy the risk of developing EoE is 2.72%. Barrier dysfunction and T-helper 2 inflammation is considered to be pathogenetically important factors. There are different patterns of clinical presentation varying with age and can be masked by adaptation habits. Besides, symptoms do not usually correlate with histologic disease activity. The diagnostic criteria for EoE has evolved but mainly requires symptoms of esophageal dysfunction with histologic evidence of a peak value of at least 15 eosinophils per high-power field. Endoscopies have to be repeated in order to diagnose, monitor, and treat EoE. Treatment of EoE can be started either by drugs (PPIs and topical corticosteroids) or elimination diets. The multistage step-up elimination diet management approach of EoE is promising. Endoscopic dilation is used for patients with severe dysphagia/food impaction with inadequate response to anti-inflammatory treatment. Conclusions: Research in recent years has contributed to a better understanding of EoE's pathogenesis, genetic background, natural history, allergy workup, standardization in assessment of disease activity, evaluation of minimally invasive diagnostic tools, and new therapeutic approaches. However, several unmet needs are to be solved urgently, as finding a non-invasive disease-monitoring methods and biomarkers for routine practice, the development or new therapies, novel food allergy testing to detect triggering foods, drug, and doses required for initial therapy and safety issues with long-term maintenance therapy, amongst others. Besides, multidisciplinary management units of EoE, involving gastroenterologists, pediatricians, allergists, pathologists, dietitians, and ENT specialists are needed.