Eosinophilic esophagitis phenotypes: Ready for prime time?

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.

Allergic phenotype identified on allergen testing is associated with proton pump inhibitor nonresponse in eosinophilic esophagitis

BACKGROUND AND AIM

Food/environmental allergens have been associated with eosinophilic esophagitis (EoE); however, the correlation between allergy profiles and disease responsiveness to proton pump inhibitor (PPI) therapy remains unclear. We aimed to assess the association between food/environmental allergies identified on allergen testing and histologic response to PPI in patients with treatment-naive EoE.

METHODS

Adults with newly diagnosed EoE who underwent formal testing for food/environmental allergies at a tertiary center were included. All patients underwent twice-daily PPI for 8 weeks with subsequent repeat endoscopy and biopsy to assess histologic response. Patients with <15 eosinophils/hpf on post-PPI mucosal biopsies were classified as responders (PPI-r-EoE), while those with ≥15 eosinophils/hpf were nonresponders (PPI-nr-EoE).

RESULTS

Sixty-one patients met inclusion criteria (21 PPI-r-EoE vs 40 PPI-nr-EoE). Demographic, clinical, and endoscopic finding variables were similar between groups. Positive food allergen test was more prevalent among PPI-nr-EoE patients (82.5% vs 42.9%, P = 0.003). On multivariable analysis, positive food allergen testing remained an independent predictor for PPI nonresponse (aOR 0.15, CI: 0.04-0.58, P = 0.0006). Positive environmental allergen testing was highly prevalent, with no significant differences between groups (77.5% vs 95.2%, P = 0.14). However, higher number of positive environmental allergens (23.3% [≥5 allergens] vs 73.3% [<5 allergens], P = 0.003) and specific aeroallergens correlated with PPI-nr-EoE.

CONCLUSION

Positive food allergy testing and increased environmental allergens predicted lower likelihood of histologic response to PPI in EoE. Our findings support an allergic phenotype of EoE that may less likely respond to PPI therapy. Formal allergen testing may play a role in therapy selection and tailored management in EoE.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

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

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Newly Proposed Severity Index for Eosinophilic Esophagitis is Associated With Baseline Clinical Features and Successful Treatment Response

BACKGROUND AND AIMS

The Index of Severity for EoE (I-SEE) was recently developed. We aimed to determine the relationship between features of eosinophilic esophagitis and disease severity, and assess change in disease severity with topical corticosteroid treatment, using I-SEE.

METHODS

We performed a post hoc analysis of an 8-week randomized trial comparing 2 topical corticosteroid formulations in newly diagnosed patients with eosinophilic esophagitis. I-SEE was calculated at baseline and posttreatment, and patients were classified as mild (1-6 points), moderate (7-14 points), severe (≥15 points), or inactive (0 points). We analyzed clinical, endoscopic, and histologic features at baseline by disease severity, and examined the change in severity before and after treatment, and by histologic response (<15 eosinophils per high-power field).

RESULTS

Of 111 subjects randomized, 20 (18%) were classified as mild, 75 (68%) as moderate, and 16 (14%) as severe at baseline. Increasing severity was associated with lower body mass index (30 for mild, 27 for moderate, 24 for severe; P = .01), longer duration of dysphagia symptoms before diagnosis (9 years for mild, 9 for moderate, and 20 for severe; P < .001), and decreasing esophageal diameter (15 mm for mild, 13 for moderate, and 10 for severe; P < .001). Mean severity score decreased after treatment (11 vs 4; P < .001), with lower scores in histologic responders compared with nonresponders (2 vs 9; P < .001). The severity score at baseline predicted need for dilation at follow-up (C statistic, 0.81).

CONCLUSIONS

The newly developed I-SEE correlates with many clinical features at diagnosis, and severity improves with successful topical corticosteroid treatment. Additional investigations in other populations can further confirm its utility.

A PhysioMechanical Model of Esophageal Function in Eosinophilic Esophagitis

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is characterized by eosinophilic inflammation, but also heterogeneous presentations involving fibrostenotic esophageal remodeling and esophageal dysmotility. We aimed to define and evaluate phenotypes of EoE using functional lumen imaging probe (FLIP) panometry (ie, a PhysioMechanical classification of EoE).

METHODS

Patients with EoE who completed FLIP during endoscopy were included in a cross-sectional study. FLIP studies were analyzed for distensibility plateau and compliance of the esophageal body, maximum esophagogastric junction diameter, and contractile response pattern. These FLIP features were then applied to define PhysioMechanical classifications.

RESULTS

A total of 215 patients with EoE (mean [standard deviation] age 38 [12] years; 31% female) were included. Seven PhysioMechanical classifications were identified that differed by various clinical characteristics, including symptom duration (P < .001) and Endoscopic EoE Reference Scores (EREFS) (P < .001). In particular, patients with "nonreactive fibrostenosis" (n = 14), had greater symptom duration (median [interquartile range] 20 [10-30] years) and more frequently had EREFS grade 2 or 3 ring scores (14 of 14 patients) than patients with a "normal" PhysioMechanical classification (symptom duration: 3 [1-8] years; 4 of 50 [8%] had EREFS grade 2 or 3 rings). In addition, among patients off treatment at cross-sectional evaluation (n = 46), there was a difference between PhysioMechanical classifications in future proton pump inhibitor (PPI) response rates (ie, achieving peak mucosal eosinophil count <15 per high-powered field after PPI treatment); P = .009. PPI response ranged from 87% (13 of 15 patients) with "isolated esophagogastric junction outflow obstruction" to 11% (1 of 9 patients) with "spastic-reactive fibrostenosis."

CONCLUSIONS

Classifying PhysioMechanical esophageal function in EoE based on FLIP panometry features may facilitate defining disease severity and directing management in EoE.

A New Tool to Assess Disease Severity in Eosinophilic Esophagitis

The presentation of eosinophilic esophagitis (EoE) is heterogeneous with varied clinical, endoscopic, and histologic features impacting the severity of the condition. Until recently, however, and in contrast with many other conditions, there has been no standardized way to measure disease severity in EoE. A clinically applicable method for assessing severity in routine practice has been recognized as necessary to standardize assessment and management of EoE. Therefore, the American Gastroenterological Association has sponsored a consensus conference to determine elements of severity in EoE and develop the first tool to measure severity. This article presents details of this severity metric, which is known as the Index of Severity in EoE (I-SEE), and outlines the elements within I-SEE and how to categorize EoE as mild, moderate, severe, or inactive. The domains of I-SEE include symptoms and complications, inflammatory features (both endoscopic and histologic), and fibrostenotic features (both endoscopic and histologic). The article also provides an update on emerging data related to I-SEE and discusses the future studies necessary to implement I-SEE as part of a treatment framework in EoE.

Eosinophilic esophagitis patients with multiple atopic conditions: Clinical characteristics and treatment response to topical steroids

BACKGROUND

Patients with eosinophilic esophagitis (EoE) typically have concomitant atopic conditions, but whether there are differences in presentation or treatment response by the number of atopic diseases is unknown.

OBJECTIVE

To determine whether patients with EoE having multiple atopic conditions have differences in presentation or response to topical corticosteroid (TCS) treatment.

METHODS

We performed a retrospective cohort study of adults and children with newly diagnosed EoE. The total number of atopic comorbidities (allergic rhinitis, asthma, eczema, food allergy) was calculated. Patients with at least 2 atopic conditions other than allergic rhinitis were defined as having multiple atopic conditions and their baseline characteristics were compared with those with less than 2 atopic conditions. Histologic, symptom, and endoscopic responses to TCS treatment were also compared with bivariable and multivariable analyses.

RESULTS

Of the 1020 patients with EoE having atopic disease information, 235 (23%) had 1 atopic comorbidity, 211 (21%) had 2, 113 (11%) had 3, and 34 (3%) had 4. At baseline, the 180 (18%) patients with 2 or more atopic diseases were younger and had more vomiting, less abdominal pain, more exudates and edema on endoscopy, and higher peak eosinophil counts. Among those treated with TCS, there was a trend toward better global symptom response in patients with less than 2 atopic conditions, but there was no difference in histologic or endoscopic response compared with those with 2 or more atopic conditions.

CONCLUSION

There were differences in the initial presentation of EoE between those with and without multiple atopic conditions, but there were no major differences in histologic treatment response to corticosteroids by atopic status.

Oral Immunotherapy and Risk of Eosinophilic Esophagitis in Children: 15 Years' Experience

OBJECTIVES

Oral immunotherapy (OIT) is an effective treatment for children with persistent food allergy, and has concerns about its safety, including eosinophilic esophagitis (EoE). The aim of this study was to evaluate the prevalence of EoE in a large cohort of children who underwent OIT in our center, and to determine if there were any clinical, endoscopic, or histologic differences depending on the food employed for the OIT.

METHODS

A retrospective study was performed over a 15-year period (2005-2020). Children who underwent cow's milk (CM), egg, and/or peanut OIT and developed EoE were included.

RESULTS

Six hundred and seven OIT were carried out (277 CM-OIT, 322 egg-OIT, and 8 peanut-OIT). Seventeen patients (2.8%) had a confirmed histologic diagnosis of EoE with a higher prevalence for patients who underwent CM-OIT (3.9%) than egg-OIT (2.2%). Symptoms suggestive of EoE and a confirmed diagnosis occurred at median times of 25 and 36 months, respectively, after the build-up phase of the OIT was completed. Choking, abdominal pain, and dysphagia were the most frequent symptoms and lamina propria fibrosis was observed in 41.2% of patients. No significant differences in clinical symptoms, endoscopic, or histologic findings between patients under CM or egg-OIT were found. One-third of patients reported mild symptoms suggestive of EoE before the OIT.

CONCLUSIONS

EoE appears to be a rare but important adverse event that can occur even years after OIT. Validated questionnaires to screen EoE before the OIT and in the follow-up of these patients may be the main tool for an early diagnosis.

Breaking down the complex pathophysiology of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic and progressive immune-mediated disease of the esophagus associated with antigen-driven type 2 inflammation and symptoms of esophageal dysfunction. Our understanding of EoE pathophysiology has evolved since its initial recognition more than 20 years ago and has translated into diagnostic and novel therapeutic approaches that are affecting patient care. The mechanisms underlying disease development and progression are influenced by diverse factors, such as genetics, age, allergic comorbidities, and allergen exposures. Central to EoE pathophysiology is a dysregulated feed-forward cycle that develops between the esophageal epithelium and the immune system. Allergen-induced, type 2-biased immune activation by the esophageal epithelium propagates a cycle of impaired mucosal barrier integrity and allergic inflammation, eventually leading to tissue remodeling and progressive organ dysfunction. Herein, we review the current understanding of fundamental pathophysiological mechanisms contributing to EoE pathogenesis.

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.

Eosinophilic esophagitis: Immune mechanisms and therapeutic targets

Eosinophilic esophagitis (EoE) is an emerging chronic inflammatory disease of the oesophagus and is clinically characterized by upper gastrointestinal (GI) symptoms including dysphagia and esophageal food impaction. Histopathologic manifestations, which include intraepithelial eosinophilic inflammation and alterations of the esophageal squamous epithelium, such as basal zone hyperplasia (BZH) and dilated intercellular spaces (DIS), are thought to contribute to esophageal dysfunction and disease symptoms. Corroborative clinical and discovery science-based studies have established that EoE is characterized by an underlying allergic inflammatory response, in part, related to the IL-13/CCL26/eosinophil axis driving dysregulation of several key epithelial barrier and proliferative regulatory genes including kallikrein (KLK) serine proteases, calpain 14 (CAPN14) and anoctamin 1 (ANO1). The contribution of these inflammatory and proliferative processes to the clinical and histological manifestations of disease are not fully elucidated. Herein, we discuss the immune molecules and cells that are thought to underlie the clinical and pathologic manifestations of EoE and the emerging therapeutics targeting these processes for the treatment of EoE.

Subtyping of Eosinophilic Esophagitis Based on Disease Presentation in a pediatric Cohort

OBJECTIVE

Eosinophilic esophagitis (EoE) is an immune-mediated inflammatory disease characterized by eosinophilic infiltration of esophageal tissue. Subtyping of EoE patients could be useful in predicting therapeutic response. We propose clinical subtypes, apply them to our pediatric EoE population retrospectively, and assess therapy choices and remission at one year.

METHODS

A retrospective chart review of pediatric patients diagnosed with EoE was conducted. Patients were grouped into proposed subtypes (severe, allergic, fibrostenotic, inflammatory, unclassified) based on presenting characteristics. The primary outcome was histologic remission, which was defined &lt;15 eosinophils/high-powered-field (hpf) at the closest visit 1 year postdiagnosis.

RESULTS

Subtyping was possible in 242 of 256 patients and follow-up histological data were available in 75 subjects. The majority had an overlap in phenotype with 17% severe, 77% allergic, 15% fibrostenotic, 60% inflammatory, and 5% unclassified, whereas 45% of the cohort were assigned to a unique subtype. At 1 year, 43/75 (57%) of patients achieved histologic remission, with an overall average decrease of 33 (IQR -47, -12) eosinophils/hpf across the entire cohort. There was no difference in remission rates among subtypes. First-line therapy review revealed higher rates of proton pump inhibitor (PPI) ± topical steroids utilization in severe patients, while topical steroids were prescribed preferentially over dietary therapy in the fibrostenotic subtype.

CONCLUSION

There were no observed differences in remission rates at 1 year among clinically defined subtypes of EoE, although this could be attributed to overlapping subtypes. Most patients responded well to medical therapy. Larger scale prospective studies designed to subtype patients and protocolize treatment may help personalize the approach to EoE management.

Disease Burden and Treatment Patterns Associated With Eosinophilic Esophagitis in the United States: A Retrospective Claims Study

GOALS

This US-based, retrospective claims study aimed to investigate disease burden and treatment patterns in patients with eosinophilic esophagitis (EoE), and to compare health care resource use (HCRU) in patients with EoE and matched controls without EoE.

MATERIALS AND METHODS

Patients with a diagnosis of EoE and ≥12 months of prediagnosis data were identified from the Truven Health MarketScan Research databases (January 2008 to September 2016) and followed up from the diagnosis date until termination of eligibility for a health plan. Patient clinical characteristics and HCRU were recorded in the 12 months before diagnosis; HCRU and treatment patterns were recorded during follow-up. HCRU in patients with EoE and matched controls was compared during the 12-month postdiagnosis period.

RESULTS

Among the 23,003 patients with EoE (mean age: 34.3 y; 64.8% male), gastroesophageal reflux disease was the most common prediagnosis condition (34.6%). After diagnosis, the most common off-label, first-line treatments were proton pump inhibitor monotherapy (52.8%) and topical corticosteroid monotherapy (21.5%). Overall, 3336 patients (14.5%) received at least 3 lines of off-label pharmacotherapy. Outpatient visits (recorded in 99.9% of patients on and postdiagnosis) were most frequently to gastroenterologists/pediatric gastroenterologists (49.5% prediagnosis, 72.6% on and postdiagnosis). Inpatient admissions and outpatient and emergency room visits were more likely in patients with EoE than in matched controls (P<0.0001).

CONCLUSIONS

Patients with EoE in the USA experience a high disease burden both before and after diagnosis, which requires significant HCRU. Our findings highlight the unmet need for adequate control of EoE-related symptoms.

Sex Differences in Blood Transcriptional Profiles and Clinical Phenotypes in Pediatric Patients with Eosinophilic Esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is an increasingly recognized, chronic inflammatory disease. Recent reports suggest clinical differences between males and females.

OBJECTIVE

To define the relevant molecular pathways that could be related to clinical phenotypes in children with EoE.

METHODS

We performed blood RNA expression analysis in children with newly diagnosed EoE and matched, healthy controls, and applied bioinformatics tools to define EoE host immune biosignatures. Questionnaires and medical records were used to characterize symptoms, esophagogastroduodenoscopy results, and treatment response.

RESULTS

Forty-one subjects (aged 2-17 years) were enrolled; the cohort consisted of 27 males and 14 females. Patients were randomly divided into a discovery cohort (21 EoE patients and 12 controls) that identified 544 significant differentially expressed transcripts (P ≤ .01; 1.25-fold change). Those 544 transcripts correctly classified most EoE patients in the validation cohort (n = 20) from healthy controls. Global transcriptional perturbation relative to healthy controls, Molecular Distance to Health scores were greater in EoE patients than controls (P = .003). When we analyzed subjects based on age and sex, males 13 years of age and older were more likely to have food impactions (P = .033) and to have higher endoscopic severity scores (P = .036). Separate group comparisons according to sex identified 294 differentially expressed transcripts in males and 643 transcripts in female EoE patients. Of those, 37 genes were shared and similarly expressed irrespective of sex.

CONCLUSIONS

Whole blood transcriptional analysis represents a promising noninvasive tool to assess activity of the immune/inflammatory response in children with EoE. Male and female EoE patients showed robust differences in gene expression suggesting distinct pathogenic endotypes.

Classification of patients with esophageal eosinophilia by patterns of sensitization revealed by a diagnostic assay for multiple allergen-specific IgEs

BACKGROUND

Eosinophilic esophagitis (EoE) is considered to be an immunoglobulin E (IgE)-mediated allergic disorder. Our goal was to examine IgE-mediated allergic sensitization patterns in patients with esophageal eosinophilia (EE).

METHODS

We enrolled subjects with EE who underwent evaluation with a diagnostic panel to document multiple allergen-specific IgEs. Statistically significant groups were identified by cluster analysis. We also defined allergens based on their characteristics including outdoor, indoor, plant, and animal allergens.

RESULTS

We classified patients with EE into 3 distinct groups, including cluster 1 (n = 62) who were minimally sensitized to most allergens except pollen and house dust, cluster 2 (n = 30) who were hypersensitized to outdoor and plant allergens, and cluster 3 (n = 15) who were hypersensitized to most allergens, most notably to indoor and animal allergens. Dysphagia reported among those in clusters 1, 2, and 3 at 35.5%, 46.7%, and 73.3%, respectively, (p = 0.028) and EoE endoscopic reference scores (EREFS) at 3.0, 6.0, and 8.0, respectively, (p < 0.001) differed significantly between the 3 clusters. Those in cluster 3 had a significantly higher prevalence of dysphagia (35.5% vs. 73.3%, p = 0.030), and higher EREFS with respect to rings (0.3 vs. 0.9, p = 0.003) and strictures (0.0 vs. 0.13, p = 0.011) compared to those in cluster 1.

CONCLUSIONS

IgE-mediated allergic sensitization patterns are associated with clinical features of patients with EE. Use of a diagnostic panel that detects multiple allergen-specific IgEs can help to explain the heterogeneous phenotype of this patient cohort.

Type 2 Immunity and Age Modify Gene Expression of Coronavirus-induced Disease 2019 Receptors in Eosinophilic Gastrointestinal Disorders

Infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can lead to coronavirus-induced disease 2019 (COVID-19). The gastrointestinal (GI) tract is now an appreciated portal of infection. SARS-CoV-2 enters host cells via angiotensin-converting enzyme-2 (ACE2) and the serine protease TMPRSS2. Eosinophilic gastrointestinal disorders (EGIDs) are inflammatory conditions caused by chronic type 2 (T2) inflammation. the effects of the T2 atopic inflammatory milieu on SARS-COV-2 viral entry gene expression in the GI tract is poorly understood. We analyzed tissue ACE2 and TMPRSS2 gene expression in pediatric eosinophilic esophagitis (EoE), eosinophilic gastritis (EG), and in normal adult esophagi using publicly available RNA-sequencing datasets. Similar to findings evaluating the airway, there was no difference in tissue ACE2/TMPRSS2 expression in EoE or EG when compared with control non-EoE/EG esophagus/stomach. ACE2 gene expression was significantly lower in esophagi from children with or without EoE and from adults with EoE as compared with normal adult esophagi. Type 2 immunity and pediatric age could be protective for infection by SARS-CoV-2 in the gastrointestinal tract because of decreased expression of ACE2.

Practice patterns and adherence to clinical guidelines for diagnosis and management of eosinophilic esophagitis among gastroenterologists

Real-world practice patterns of eosinophilic esophagitis (EoE) among gastroenterologists are not well-described. The aim is to describe practice patterns of EoE diagnosis and management and assess concordance with consensus guidelines. We conducted a cross-sectional online survey of gastroenterologists in the USA using Qualtrics, which was dispersed through the North Carolina Society of Gastroenterology (NCSG) and the American College of Gastroenterology member listservs. A similar survey was sent to NCSG members in 2010 and responses were compared in a subanalysis. Of 240 respondents, 37% (n = 80) worked in an academic setting versus 63% (n = 138) community practice setting. Providers saw a median of 18 (interquartile range 2-100) EoE patients annually and 24% (n = 52) were 'very familiar' with EoE guidelines. A proton-pump inhibitor (PPI) trial was required by 37% of providers prior to EoE diagnosis. In total, 60% used a ≥15 eosinophils per high-power field cut point for diagnosis and 62% biopsied from the proximal and distal esophagus on initial exam. Only 12% (n = 28) followed EoE diagnosis guidelines. For first-line treatment, 7% used dietary therapy, 32% topical steroids, and 61% used PPIs; 67% used fluticasone as first-line steroid; 41% used maintenance steroid treatment in responders. In the NCSG cohort, a higher proportion in 2017 followed guideline diagnosis recommendations compared with 2010 (14% vs. 3%; P = 0.03) and a higher proportion used dietary therapy as first-line treatment (13% vs. 3%; P = 0.046). There is variability in EoE practice patterns for EoE management, with management differing markedly from consensus guidelines. Further education and guideline dissemination are needed to standardize practice.

Phenotypes and endotypes in eosinophilic esophagitis

OBJECTIVE

To improve understanding of the heterogeneous presentation of eosinophilic esophagitis (EoE), and its different potential phenotypes and endotypes.

DATA SOURCES

We reviewed studies addressing EoE genetics, risks, natural history, treatment, phenotype, or endotype to assess data relating to differences in the presentation of EoE in children and adults. This review was restricted to articles in the English language.

STUDY SELECTIONS

Data source abstracts, pertinent articles, and book chapters meeting the objectives were critically reviewed.

RESULTS

Data to support differing phenotypes and endotypes in EoE are emerging, but findings are based on multiple studies and therefore sometimes incomparable. Like other atopic disorders EoE is a complex disease with diverse clinical presentations (phenotypes) based on response to therapy, natural history, and association with atopic comorbidities. Different pathogenetic mechanisms (endotypes) may drive the multiple phenotypes. T Helper type 2 inflammation, epithelial barrier defects, enhanced fibrosis, and association with rare monogenetic diseases are the most described endotypes in EoE.

CONCLUSION

Eosinophilic esophagitis is an atopic disorder that is increasing in prevalence and can be difficult to treat. Better understanding of phenotypes and endotypes in EoE may enable future care to be individualized more effectively, resulting in shorter time to remission and fewer endoscopies.

EoE disease monitoring: Where we are and where we are going

OBJECTIVE

To review literature on various methods of monitoring and characterizing eosinophilic esophagitis (EoE) with respect to their validity as well as risk to the patient.

DATA SOURCES

A literature search was performed using PubMed with keyword combinations of EoE and monitoring as well as various techniques used for monitoring, including but not limited to, symptoms, endoscopy, histology, fluoroscopy, FLIP, noninvasive monitoring, and biomarkers.

STUDY SELECTIONS

Case-control studies, observational studies, peer-reviewed reviews and guidelines, and systematic reviews were selected, reviewed, and summarized here.

RESULTS

A wealth of research regarding monitoring of EoE is currently being undertaken and published. Our review highlights those that have been validated and are currently being used, as well as some that show promise for future monitoring and disease characterization.

CONCLUSION

Eosinophilic esophagitis is a chronic condition that at this time requires upper endoscopy as the gold standard of diagnosis and monitoring. There is a great need in the field for less invasive monitoring tools and better ways to characterize disease to allow for personalization of therapies.

Symptom Burden and Quality of Life Over Time in Pediatric Eosinophilic Esophagitis

OBJECTIVE

The aim of the study was to evaluate whether children with eosinophilic esophagitis (EoE) demonstrated an association between health-related quality of life (HRQoL) improvements and symptom reduction during 12 months of treatment; to examine age-related EoE discrete symptom presentation; and to describe residual symptom and HRQoL burden.

METHODS

Children ages 2 to 18 years with EoE were assessed at the onset of treatment and 12 months later at 4 tertiary care centers. Continuous measures of symptoms and symptom severity were based on 8 discrete EoE symptoms. HRQoL was measured with the Pediatric Quality of Life (PedsQL) parent-proxy (PR) report, child self-report (CR), and Family Impact Module. Mixed-effects modeling was used to test changes over time for symptom burden and child and family HRQoL.

RESULTS

One hundred nine children were followed (ages 2-18 years, mean age 7.6 [4.6] years, 77% boys, 87% white). Baseline symptom number mean was 3.5 (standard deviation = 2.3, range 0-8) and symptom severity mean was 5.5 (standard deviation = 4.3, range 0-24). EoE symptom number and symptom severity decreased significantly over the 12 months (P = 0.013, P < 0.001, respectively). PedsQL PR Total, Physical, Psychosocial, and Family Impact scores all improved significantly (P = 0.001, 0.012, 0.012, 0.015, respectively) but PedsQL child self-report scores did not. Symptom reduction correlated with PR PedsQL improvement (P = 0.01). Few discrete symptoms completely remitted, but lowered severity ratings indicated clinically significant improvement.

CONCLUSIONS

Year-long treatment in multidisciplinary tertiary centers reduced most symptoms and improved parent-reported HRQoL in children with EoE. The frequency of residual symptoms and persistently lower HRQoL, however, underscore the chronic nature of pediatric EoE.

Understanding allergic multimorbidity within the non-eosinophilic interactome

BACKGROUND

The mechanisms explaining multimorbidity between asthma, dermatitis and rhinitis (allergic multimorbidity) are not well known. We investigated these mechanisms and their specificity in distinct cell types by means of an interactome-based analysis of expression data.

METHODS

Genes associated to the diseases were identified using data mining approaches, and their multimorbidity mechanisms in distinct cell types were characterized by means of an in silico analysis of the topology of the human interactome.

RESULTS

We characterized specific pathomechanisms for multimorbidities between asthma, dermatitis and rhinitis for distinct emergent non-eosinophilic cell types. We observed differential roles for cytokine signaling, TLR-mediated signaling and metabolic pathways for multimorbidities across distinct cell types. Furthermore, we also identified individual genes potentially associated to multimorbidity mechanisms.

CONCLUSIONS

Our results support the existence of differentiated multimorbidity mechanisms between asthma, dermatitis and rhinitis at cell type level, as well as mechanisms common to distinct cell types. These results will help understanding the biology underlying allergic multimorbidity, assisting in the design of new clinical studies.

Sensitivity and Specificity of Administrative Medical Coding for Pediatric Eosinophilic Esophagitis

OBJECTIVES

Eosinophilic esophagitis (EoE) is a delayed-type hypersensitivity with increasing rates among pediatric populations. Although studies have used International Classification of Diseases (ICD) coding to define local cohorts and report disease epidemiology, the accuracy of the EoE ICD code for pediatric EoE is unknown.

METHODS

We searched the Intermountain Healthcare Database for pediatric cases with the EoE ICD code over a 5-year period. We cross-referenced these results with a recently published pediatric EoE cohort from the same region and period, where incident cases were identified via retrospective review of pathology reports and medical records. Using the retrospective review cohort as the reference standard, we evaluated the accuracy of the EoE ICD code.

RESULTS

Via retrospective review, we identified 1129 new pediatric EoE cases in the Intermountain Healthcare system over 5 years. Six hundred ten of these had the EoE ICD code associated with their chart. Out of 878,872 unique pediatric records in the Intermountain Healthcare system, 219 had the EoE ICD code incorrectly applied. The specificity of the EoE ICD code in children was 99%, but sensitivity and positive predictive value were 61% and 79%, respectively.

CONCLUSIONS

The EoE ICD code has strengths and weaknesses in pediatrics. The EoE ICD code is specific, with few false positives across a large population, but not sensitive. The low sensitivity is likely multifactorial and requires further evaluation. Compared to retrospective chart review, which allows for application of clinicopathologic EoE diagnostic criteria, sole use of ICD codes results in underascertainment of EoE cases and key misclassifications.

Allergic Comorbidity in Eosinophilic Esophagitis: Mechanistic Relevance and Clinical Implications

Allergic eosinophilic esophagitis (EoE) is a chronic, allergen-mediated inflammatory disease of the esophagus, and the most common cause of prolonged dysphagia in children and young adults in the developed world. While initially undistinguished from gastroesophageal reflux disease-associated esophageal eosinophilia, EoE is now recognized as a clinically distinct entity that shares fundamental inflammatory features of other allergic conditions and is similarly increasing in incidence and prevalence. The clinical and epidemiologic associations between EoE and other allergic manifestations are well established. In addition to exaggerated rates of atopic dermatitis, IgE-mediated food allergy, asthma, and allergic rhinitis in EoE patients, each of these allergic manifestations imparts individual and cumulative risk for subsequent EoE diagnosis. As such, EoE may be a member of the "allergic march"-the natural history of allergic manifestations during childhood. Several determinants likely contribute to the relationship between these conditions, including shared genetic, environmental, and immunologic factors. Herein, we present a comprehensive review of allergic comorbidity in EoE. We discuss areas of the genome associated with both EoE and other allergic diseases, including the well-studied variants encoding thymic stromal lymphopoietin and calpain 14, among other "atopic" regions. We summarize ways that environmental factors (such as microbiome-altering pressures and aeroallergen exposure) may predispose to multiple allergic conditions including EoE. Finally, we touch on some fundamental features of type 2 inflammation, and the resulting implications for the development of multiple allergic manifestations. We conclude with an analysis of the "type 2" biologics, and how mechanistic similarities between EoE and the other allergic manifestations have important implications for screening and treatment of the allergic patient.

A 12-Week Maintenance Therapy with a New Prepared Viscous Budesonide in Pediatric Eosinophilic Esophagitis

BACKGROUND

A new prepared oral viscous budesonide (PVB) has been effective in inducing clinical and histological remission in pediatric eosinophilic esophagitis (EoE).

AIMS

To evaluate the efficacy of a 12-week maintenance therapy on clinical, endoscopic, and histological remission using half of the dose used in the induction therapy.

METHODS

We prospectively enrolled pediatric patients with active EoE. After 12 weeks of induction therapy with PVB (< 150 cm: 2 mg/day; ≥ 150 cm: 4 mg/day) patients received a maintenance dose of half of the dose used in the induction therapy (1 mg or 2 mg) for another 12 weeks. A 12-week follow-up was then performed in all patients after the end of therapy. Endoscopy was performed at weeks 0, 12, 24, and 36. Symptoms, endoscopy, and histology scores were also calculated. Serum cortisol was evaluated during the treatment period.

RESULTS

We enrolled 20 children (15 males; median age 10 years; range 4-17). After the 12-week induction therapy 18 patients (90%) were in remission, with a significant decrease in the median peak of eosinophil count/HPF as well as a marked reduction in clinical, endoscopic, and histological scores (p < 0.01). At the end of the maintenance therapy (week 24), 17 patients (85%) were still in remission, while there were only 9 at week 36 (45%). No significant changes in cortisol levels were observed during the study period.

CONCLUSIONS

The 12-week maintenance treatment with the half the dose of PVB was effective in sustaining remission at week 24; however, no reduction in the rate of relapse after suspension of treatment occurred.

Epithelial-stromal crosstalk and fibrosis in eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a food allergen-induced inflammatory disorder. EoE is increasingly recognized as a cause of swallowing dysfunction, food impaction and esophageal stricture. Inflammation of the esophageal mucosa involves immune cell infiltrate, reactive epithelial changes and fibroblast activation, culminating in robust tissue remodeling toward esophageal fibrosis characterized by excess collagen deposition in the subepithelial lamina propria. Fibrosis contributes to a unique mechanical property of the EoE-affected esophagus that is substantially stiffer than the normal esophagus. There is a great need to better understand the processes behind esophageal fibrosis in order to foster improved diagnostic tools and novel therapeutics for EoE-related esophageal fibrosis. In this review, we discuss the role of esophageal inflammatory microenvironment that promotes esophageal fibrosis, with specific emphasis upon cytokines-mediated functional epithelial-stromal interplays, recruitment and activation of a variety of effector cells, and tissue stiffness. We then explore the current state of clinical methodologies to detect and treat the EoE-related esophageal stricture.

Incidence and Prevalence of Pediatric Eosinophilic Esophagitis in Utah Based on a 5-Year Population-Based Study

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is often detected in children and is considered to be a rare disease, with prevalence values reported to be below 60 cases per 100,000 persons. To determine whether the incidence of EoE in children in Utah exceeds estimates from regional reports, we calculated incidence and prevalence values over a 5-year period.

METHODS

Using consensus guidelines for the diagnosis of EoE, we reviewed pathology records from the Intermountain Healthcare pathology database, from July 1, 2011 through June 31, 2016. We collected data on 10,619 pediatric patients with available esophageal biopsy results, and identified cases of esophageal eosinophilia (>14 eosinophils in a high-power microscopy field in an endoscopic biopsy). An EoE case required the presence of esophageal eosinophilia, symptoms of esophageal dysfunction, and the absence of co-morbid conditions that may cause esophageal eosinophilia. Annual pediatric EoE incidence and prevalence values were calculated per 100,000 children, based on averaged pediatric population estimates from census figures of Utah in 2010 and 2016.

RESULTS

We identified 1281 unique pediatric patients who met criteria for esophageal eosinophilia. Of those, 1060 patients met criteria for newly diagnosed EoE. Over the 5-year period studied, the average annual pediatric EoE incidence in Utah was 24 cases per 100,000 children. The prevalence in year 5 of the study was 118 cases per 100,000 children.

CONCLUSION

In a population-based study of children in Utah, we found the incidence and prevalence of pediatric EoE to be higher than previously reported. This could be due to the prominence of EoE risk factors in this region, as well as Utah's searchable medical record system that allows for reliable case ascertainment. Further studies of this type could increase disease awareness, prompting early referral to pediatric gastroenterologists and trials to strengthen evidence-based, algorithmic approaches to EoE diagnosis and treatment in children.

Pediatric Eosinophilic Esophagitis Endotypes: Are We Closer to Predicting Treatment Response?

Eosinophilic esophagitis (EoE) is a chronic, food antigen-driven gastrointestinal disease that is characterized by esophageal eosinophilia. Currently, there are no Food and Drug Administration (FDA)-approved treatments for EoE, but the two most commonly prescribed therapies include topical corticosteroids and food elimination diets. Clinical trials have revealed a significant proportion of cases that are resistant to topical corticosteroids, and although we define EoE as a food antigen-driven disease, not all patients with EoE respond to elimination diets or even elemental diets. The varied response to treatments highlights the heterogeneity of EoE and the need for new treatment strategies. Despite the clinical differences in treatment response, predicting the outcome remains difficult since factors including age, histologic severity at diagnosis, atopic history, and anthropometrics are not predictive of treatment response. In our practice at an academic pediatric referral center, we observe distinct clinical EoE phenotypes, including cases with atopy, connective tissue disorders, or responsiveness to a proton pump inhibitor. Similar to the work in progress with asthma, stratification of patients with EoE by clinical phenotypes and/or molecular endotypes will likely assist with therapy selection and prediction of natural history. Molecular analysis with gene expression panels also shows promise in helping us classify patients based on molecular endotypes. In additional to the clinical and molecular classifications, more accurate histologic diagnostic criteria for EoE may help us tease out small differences between patient cohorts. Despite the leaps in knowledge over the past decade regarding EoE pathogenesis, it remains a challenge to predict the response to treatment. Future studies focused on molecular, genetic, and immunologic analyses of larger patient cohorts are needed to assist in identifying EoE phenotypes and endotypes as we attempt to improve patient outcomes in pediatric EoE.

Gene expression-phenotype associations in adults with eosinophilic esophagitis

BACKGROUND

Gene expression patterns have not been extensively examined in the context of clinical features of eosinophilic esophagitis (EoE).

AIMS

To assess whether gene expression is associated with clinically defined phenotypes in adults with EoE.

METHODS

This was an analysis of prospectively collected esophageal biopsies in newly diagnosed EoE patients. We determined differential gene expression with a 94 gene panel in relation to clinical features and phenotypes. These included: endoscopic findings of esophageal rings, stricture, narrowing, linear furrows, exudates, edema, and dilation; an allergic phenotype; an inflammatory phenotype, and a fibrostenotic phenotype.

RESULTS

In 89 EoE cases analyzed, patients with exudates on endoscopy had multiple differences in gene expression compared to patients without exudates, though patients with exudates also had higher eosinophil counts (172 vs 106eos/hpf; p=.01). Genes associated with esophageal narrowing included CCL26 (q-value=0.028), ALOX15 (q=0.011), GRK5 (q=0.029), CPA3 (q=0.012), and TRIM2 (q=0.0027). TRIM2 was also associated with the fibrostenotic phenotype (q=0.0051). No genes were associated with the inflammatory or atopic phenotypes, or with dilation.

CONCLUSIONS

Multiple genes are associated with exudates, possibly related to higher eosinophil counts. However, a number of genes, including those related to both inflammation and remodelling, are associated with esophageal narrowing. In particular, TRIM2 is associated with clinical fibrotic phenotypes.

Eosinophilic gastrointestinal diseases beyond eosinophilic esophagitis

OBJECTIVE

Eosinophilic gastrointestinal diseases (EGIDs) are a rare group of disorders that can have varied clinical presentations dependent on the involved segment within the gastrointestinal tract. Eosinophilic gastritis presents with abdominal pain or vomiting, eosinophilic gastroenteritis presents with diarrhea and anemia or hypoalbuminemia, and eosinophilic colitis can present with diarrhea or bloody stools. These nonspecific symptoms remain poorly understood in their relation to the underlying pathogenesis, but a significant percentage of patients have atopy. In this review, we discuss the current literature on EGIDs to promote a practical approach to diagnosis and care.

DATA SOURCES

Review of published literature.

STUDY SELECTIONS

Clinically relevant literature from 1900 through 2018 was obtained from a PubMed search. Those that addressed prevalence, diagnosis, clinical manifestations, natural history, and treatment of EGIDs were reviewed and are summarized in this article.

RESULTS

Of the 485 articles found in the search, most of which were case reports, 71 were selected for review. The natural history of EGIDs is based primarily on case series and small numbers of patients, making therapeutic decisions difficult. Treatment remains limited to dietary restriction that is not effective in many patients and topical or systemic corticosteroids whose long-term use is to be avoided if possible.

CONCLUSION

With the seeming increase in all types of EGIDs, phenotypic descriptions are emerging that will likely promote better understanding of the pathogenesis and identification of novel therapeutic targets.

What Is the Relationship Between Eosinophilic Esophagitis (EoE) and Aeroallergens? Implications for Allergen Immunotherapy

PURPOSE OF REVIEW

Observations suggesting that aeroallergens trigger eosinophilic esophagitis (EoE) in a subset of patients raise questions about the implications this finding has on the evaluation and management of patients with EoE, including a potential role for allergen immunotherapy.

RECENT FINDINGS

The majority of studies evaluating the potential role of aeroallergens as provocateurs of EoE have addressed this issue by assessing the seasonal variation in EoE diagnosis and/or symptom onset or worsening, with mixed results. For various reasons, reaching accurate conclusions based on this methodology is potentially fraught with error. In addition, studies examining the even harder to assess role of perennial aeroallergens in triggering EoE are lacking. Although clearly not the majority, there may be a subset of patients with EoE and allergic rhinitis in whom exposure to aeroallergens to which they are sensitized contributes to esophageal eosinophilia either through direct chronic esophageal mucosal contact with pollen allergens or from repetitive exposure of the esophageal mucosa to pollen allergens, mediators, and eosinophils in swallowed nasal secretions. Therefore, evaluation for and optimal treatment of comorbid allergic rhinitis in EoE patients are clearly indicated. Recognition of the potential role of aeroallergens as triggers of EoE also raises the question of whether allergen immunotherapy might be an effective form of EoE treatment. Reports of sublingual immunotherapy (SLIT) inducing EoE support the notion that aeroallergens can trigger EoE, but negate this approach as a potential form of EoE therapy. In fact, the use of SLIT is contraindicated in patients with EoE. The literature regarding the role of subcutaneous immunotherapy (SCIT) in patients with EoE is limited. Current evidence indicates that it should not be typically recommended; however, SCIT might benefit a subset of patients with EoE and uncontrolled allergic rhinitis on conventional therapies in whom SCIT would otherwise be indicated for allergic rhinoconjunctivitis, particularly in those with sensitizations to pollens containing allergens that cross react with food allergens. The purpose of this review is to discuss the current literature examining the role of aeroallergens in triggering EoE with a focus on the potential clinical implications of this finding on managing patients with EoE.

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

BACKGROUND

Eosinophilic oesophagitis is understood in terms of quantifiable histological, endoscopic, and molecular features. Data are scant for inter-relations of these features and their potential to identify distinct disease endotypes. We aimed to identify clinical-pathological correlations between endoscopic and histological disease variables by transcription profiling of the oesophagus of patients with eosinophilic oesophagitis of varying severity and disease activity states.

METHODS

We did a cross-sectional study across ten hospital sites in the USA associated with the Consortium of Eosinophilic Gastrointestinal Disease Researchers. We analysed oesophageal biopsy specimens taken from paediatric and adult patients with eosinophilic oesophagitis (discovery cohort), using the eosinophilic oesophagitis diagnostic panel (EDP), a set of 96 informative transcripts. Histological and endoscopic features were assessed by quantification of oesophageal eosinophils and use of the eosinophilic oesophagitis histology scoring system (HSS) and the eosinophilic oesophagitis endoscopic reference score (EREFS). Associations among the various histological, endoscopic, and molecular features were analysed by Spearman correlation. Results were replicated in a biologically independent, single-centre, validation cohort of patients with active eosinophilic oesophagitis.

FINDINGS

The discovery cohort contained 185 samples and the validation cohort comprised 100 specimens. In the discovery cohort, EDP showed intersite consistency, significant correlation with oesophageal eosinophils (p<0·0001), and similar findings between paediatric and adult patients. Of eight HSS domains, basal zone hyperplasia correlated with the EDP (median Spearman ρ 0·47 [IQR 0·36-0·60]). Of five EREFS features, distal furrows correlated with the EDP (median Spearman ρ 0·42 [0·32-0·50]). By analysing active eosinophilic oesophagitis in the discovery cohort, the EDP identified three clusters associated with distinct endotypes (termed EoEe1-3) despite similar eosinophil levels. EoEe1 was associated with a normal-appearing oesophagus (risk ratio [RR] 3·27, 95% CI 1·04-10·27; p=0·0443), an inverse association with a history of oesophageal dilation (0·27, 0·09-0·82; p=0·0105) and showed relatively mild histological, endoscopic, and molecular changes. EoEe2 showed an inflammatory and steroid-refractory phenotype (RR 2·77, 95% CI 1·11-6·95; p=0·0376) and had the highest expression of inflammatory cytokines and steroid-responding genes. EoEe3 was associated with a narrow-calibre oesophagus (RR 7·98, 95% CI 1·84-34·64; p=0·0013) and adult onset (2·22, 1·19-4·12; p=0·0155), and showed the highest degree of endoscopic and histological severity and the lowest expression of epithelial differentiation genes. These endotypes were replicated in the validation cohort by clustering and with an eosinophilic oesophagitis endotype-prediction algorithm.

INTERPRETATION

Our new disease classification stratifies patients with eosinophilic oesophagitis into subgroups with potential clinical and therapeutic significance and provides a framework for a precision medicine approach to eosinophilic oesophagitis.

FUNDING

National Institutes of Health.

An algorithm for the classification of mRNA patterns in eosinophilic esophagitis: Integration of machine learning

BACKGROUND

Diagnostic evaluation of eosinophilic esophagitis (EoE) remains difficult, particularly the assessment of the patient's allergic status.

OBJECTIVE

This study sought to establish an automated medical algorithm to assist in the evaluation of EoE.

METHODS

Machine learning techniques were used to establish a diagnostic probability score for EoE, p(EoE), based on esophageal mRNA transcript patterns from biopsies of patients with EoE, gastroesophageal reflux disease and controls. Dimensionality reduction in the training set established weighted factors, which were confirmed by immunohistochemistry. Following weighted factor analysis, p(EoE) was determined by random forest classification. Accuracy was tested in an external test set, and predictive power was assessed with equivocal patients. Esophageal IgE production was quantified with epsilon germ line (IGHE) transcripts and correlated with serum IgE and the T_h2-type mRNA profile to establish an IGHE score for tissue allergy.

RESULTS

In the primary analysis, a 3-class statistical model generated a p(EoE) score based on common characteristics of the inflammatory EoE profile. A p(EoE) ≥ 25 successfully identified EoE with high accuracy (sensitivity: 90.9%, specificity: 93.2%, area under the curve: 0.985) and improved diagnosis of equivocal cases by 84.6%. The p(EoE) changed in response to therapy. A secondary analysis loop in EoE patients defined an IGHE score of ≥37.5 for a patient subpopulation with increased esophageal allergic inflammation.

CONCLUSIONS

The development of intelligent data analysis from a machine learning perspective provides exciting opportunities to improve diagnostic precision and improve patient care in EoE. The p(EoE) and the IGHE score are steps toward the development of decision trees to define EoE subpopulations and, consequently, will facilitate individualized therapy.