The Immunologic Mechanisms of Eosinophilic Esophagitis

Effect of benralizumab on histopathology and inflammatory signatures in a clinical cohort of eosinophilic esophagitis

A preliminary report from the recent phase 3 trial of benralizumab, a monoclonal antibody that binds to interleukin-5 receptor alpha (IL5Rα), in patients with EoE revealed that medication use led to tissue eosinophil eradication but did not meet the clinical endpoint of symptom resolution. Here, we characterized the clinical, endoscopic, histologic, and transcriptional changes in patients with active EoE following benralizumab treatment. We retrospectively examined patients with EoE treated with benralizumab at the University of Utah (n = 11) and reviewed reported clinical symptoms, circulating and tissue eosinophilia, and endoscopic and histologic scores. Gene expression profiles from available esophageal tissue from benralizumab-treated patients were compared to those from patients with remission EoE (n = 5), active EoE (n = 10), and controls (n = 22). Benralizumab treatment resulted in partial symptom improvement and significant reduction in tissue eosinophilia, and endoscopic and histologic disease scoring (P < 0.01). Histologic score reductions were driven by eosinophil feature scores, while scores for epithelial features (basal cell hyperplasia and dilated intercellular spaces) were similar to those in active EoE. The gene signatures in benralizumab-treated patients mimicked those of active EoE (e.g. upregulation of POSTN, CDH26, CCL26, and downregulation of DSG1). RNA profiles and pathways support histologic findings of impaired epithelial function that persists despite benralizumab treatment. In conclusion, despite eosinophil eradication, patients treated with benralizumab had persistent epithelial injury at the histologic and transcriptional level. In this cohort, benralizumab therapy failed to eradicate inflammation and epithelial dysfunction showing that interleukin-5 receptor alpha blockade monotherapy is insufficient to control EoE.

In Vivo Raman Spectroscopy Reveals Biochemical Composition of the Esophageal Tissue in Pediatric Eosinophilic Esophagitis

INTRODUCTION

Biochemical alterations in the esophagus of patients with eosinophilic esophagitis (EoE) are poorly understood. We used Raman spectroscopy through a pediatric endoscope to identify key Raman features reflective of the esophageal biochemical composition to differentiate between children with EoE from non-EoE controls and between children with active (aEoE) and inactive EoE (iEoE).

METHODS

Spectral measurements were obtained using a customized pediatric endoscope-compatible fiber-optic Raman probe in real time during an esophagogastroduodenoscopy. Chemometric analysis was performed to identify key Raman features associated with EoE. Pearson correlation analysis was used to assess relationship between the key Raman features and EoE activity indices. Their diagnostic utility was ascertained using the receiver operator characteristic curve analysis.

RESULTS

Forty-three children were included in the study (EoE = 32 [74%] and non-EoE control = 11 [26%]; aEoE = 20 [63%] and iEoE = 12 [37%]). Raman intensities assigned to lipids, proteins, and glycogen:protein ratio accurately distinguished children with EoE from those without EoE and aEoE from iEoE. They significantly correlated with EoE activity indices. The Raman peak ratio for lipids had 90.6% sensitivity, 100% specificity, and an area under the curve of 0.95 to differentiate children with EoE from non-EoE controls. The glycogen:protein ratio had 70% sensitivity, 91.7% specificity, and an area under the curve of 0.75 to distinguish children with aEoE from iEoE.

DISCUSSION

Real-time intraendoscopy Raman spectroscopy is an effective method for identifying spectral markers reflective of the esophageal biochemical composition in children with EoE. This technique may aid in the diagnosis and monitoring of EoE and help to elucidate EoE pathogenesis.

Gastrointestinal Comorbidities Associated with Atopic Dermatitis-A Narrative Review

The current understanding of atopic dermatitis (AD) seems to be extending beyond a skin-confined condition frequently associated with allergic comorbidities, as in a number of epidemiological studies, the prevalence rate of a range of illnesses has been determined to be greater in patients with AD, or inversely. In most cases, the reasons for this are vague. A subset of these conditions are gastrointestinal disorders, including food sensitization (FS) and food allergy (FA), eosinophilic esophagitis (EoE) (it is of mixed background, both IgE-dependent and independent), food protein-induced enterocolitis syndrome (FPIES) (it exemplifies an IgE-independent food allergy), Crohn's disease (CD), colitis ulcerosa (CU), celiac disease, irritable bowel syndrome (IBS), and gastroesophageal reflux disease (GERD). In this review, we performed a comprehensive search of the literature using the PubMed database. We addressed the epidemiology of the increased co-occurrence of these diseases with AD and discussed potential causes for this subject. Multiple gastroenterological comorbidities appear to be more common in patients with AD, according to our review. The mechanisms that underlie this phenomenon are largely unknown, highlighting the need for further study in this field.

Higher Body Mass Index Is Associated With Decreased Treatment Response to Topical Steroids in Eosinophilic Esophagitis

BACKGROUND & AIMS

Understanding which eosinophilic esophagitis (EoE) patients will respond to treatment with topical corticosteroids (tCS) remains challenging, and it is unknown whether obesity impacts treatment response. This study aimed to determine whether treatment outcomes to tCS in EoE patients vary by body mass index (BMI).

METHODS

This retrospective cohort study of the University of North Carolina EoE Clinicopathologic database assessed subjects age 14 years or older with a new diagnosis of EoE. Their BMI was calculated and histologic, symptom, and endoscopic responses were recorded after tCS treatment. The treatment response of obese (BMI, ≥30 kg/m2) and nonobese EoE status was compared using bivariate and multivariate analyses.

RESULTS

We identified 296 EoE patients treated with tCS. Baseline characteristics were similar, although obese EoE patients had more heartburn and hiatal hernias. Histologic response was higher for those who were nonobese compared with obese at fewer than 15 (61% vs 47%; P = .049) and 6 or fewer (54% vs 38%; P = .02) eosinophils per high-power field, respectively. In addition, nonobese patients had significantly greater endoscopic and symptomatic responses. On multivariate analysis, increasing BMI was associated independently with decreased histologic response after accounting for age, heartburn, dilation, and hiatal hernia whether BMI was assessed as a continuous variable (adjusted odds ratio [aOR], 0.93; 95% CI, 0.89-0.98), as nonobese vs obese (aOR, 0.38; 95% CI, 0.21-0.68), or in 4 categories (overweight vs normal [aOR, 0.46; 95% CI, 0.26-0.84] or obese vs normal [aOR, 0.26; 95% CI, 0.13-0.51]).

CONCLUSIONS

As BMI increases in EoE patients, the odds of histologic, symptomatic, and endoscopic responses to tCS decreases, with obese patients having an approximately 40% decrease in odds of response.

Emerging roles of a chemoattractant receptor GPR15 and ligands in pathophysiology

Chemokine receptors play a central role in the maintenance of immune homeostasis and development of inflammation by directing leukocyte migration to tissues. GPR15 is a G protein-coupled receptor (GPCR) that was initially known as a co-receptor for human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV), with structural similarity to other members of the chemoattractant receptor family. Since the discovery of its novel function as a colon-homing receptor of T cells in mice a decade ago, GPR15 has been rapidly gaining attention for its involvement in a variety of inflammatory and immune disorders. The recent identification of its natural ligand C10orf99, a chemokine-like polypeptide strongly expressed in gastrointestinal tissues, has established that GPR15-C10orf99 is a novel signaling axis that controls intestinal homeostasis and inflammation through the migration of immune cells. In addition, it has been demonstrated that C10orf99-independent functions of GPR15 and GPR15-independent activities of C10orf99 also play significant roles in the pathophysiology. Therefore, GPR15 and its ligands are potential therapeutic targets. To provide a basis for the future development of GPR15- or GPR15 ligand-targeted therapeutics, we have summarized the latest advances in the role of GPR15 and its ligands in human diseases as well as the molecular mechanisms that regulate GPR15 expression and functions.

Endotyping Chronic Rhinosinusitis with Nasal Polyps: Understanding Inflammation Beyond Phenotypes

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogenous group of inflammatory conditions impacting the nose and paranasal sinuses. Our understanding of the underlying pathobiology of CRSwNP has substantially improved due to ongoing translational research efforts. Advances in treatment options, including targeted respiratory biologic therapy for CRSwNP, allow for more personalized approaches for CRSwNP patient care. Patients with CRSwNP are typically classified to one or more endotype based on the presence of type 1, type 2, and type 3 inflammation. This review will discuss recent advances in our understanding of CRSwNP and how this may impact current and future treatment approaches for patients with CRSwNP.

Computational analysis to define efficacy & molecular mechanisms of 7, 4'- Dihydroxyflavone on eosinophilic esophagitis: Ex-vivo validation in human esophagus biopsies

Introduction

Eosinophilic Esophagitis (EoE) is a chronic condition characterized by eosinophilic inflammation of the esophagus which leads to esophageal dysfunction with common symptoms including vomiting, feeding difficulty, dysphagia, abdominal pain. Current main treatment options of EoE include dietary elimination and swallowed steroids. Diet elimination approach could lead to identifying the trigger food(s), but it often requires repeated upper endoscopy with general anesthesia and potentially could negatively affect nutrition intake and growth of the child and individuals' quality of life. Although the swallowed steroid treatment of effective, the EoE will universally recur after discontinuation of the treatment. Digestive Tea formula (DTF) has been used by the Traditional Chinese Medicine (TCM) practice to improve GI symptoms in EoE patients, including abdominal pain, GE reflux, and abnormal bowel movement. Previously, a flavonoid small molecule compound 7, 4 dihydroxy flavone (DHF) from Glycyrrhiza uralensis in DTF inhibited eotaxin, Th2 cytokine and IgE production in vitro and in vivo.

Method

This study comprehensively evaluates the potential therapeutic and immunological mechanisms underlying DHF improvement of symptoms related to EoE using computational modeling, including target mining, gene ontology enrichment, pathway analyses, protein-protein interaction analyses, in silico molecular docking and dynamic simulation followed by ex-vivo target validation by qRT-PCR using cultured human esophagus biopsy specimen with or without DHF from patients with EoE.

Results

Computational analyses defined 29 common targets of DHF on EoE, among which TNF-α, IL-6, IL1β, MAPK1, MAPK3 and AKT1 were most important. Docking analysis and dynamic simulation revealed that DHF directly binds TNF-α with a free binding energy of -7.7 kcal/mol with greater stability and flexibility. Subsequently, in the human esophagus biopsy culture system, significant reduction in levels of TNF-α, IL-6, IL-8 and IL1-β was found in the supernatant of biopsy sample cultured with DHF. Furthermore, the gene expression profile showed significant reduction in levels of TNF-α, IL1-β, IL-6, CCND and MAPK1 in the esophagus biopsy sample cultured with DHF.

Discussion

Taken together, the current study provides us an insight into the molecular mechanisms underlying multi-targeted benefits of DHF in the treatment of EoE and paves the way for facilitating more effective EoE therapies.

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.

A comprehensive summary of disease variants implicated in metal allergy

Allergic disease represents one of the most prominent global public health crises of the 21^st century. Although many different substances are known to produce hypersensitivity responses, metals constitute one of the major classes of allergens responsible for a disproportionately large segment of the total burden of disease associated with allergy. Some of the most prevalent forms of metal allergy - including allergic contact dermatitis - are well-recognized; however, to our knowledge, a comprehensive review of the many unique disease variants implicated in human cases of metal allergy is not available within the current scientific literature. Consequently, the main goal in composing this review was to (1) generate an up-to-date reference document containing this information to assist in the efforts of lab researchers, clinicians, regulatory toxicologists, industrial hygienists, and other scientists concerned with metal allergy and (2) identify knowledge gaps related to disease. Accordingly, an extensive review of the scientific literature was performed - from which, hundreds of publications describing cases of metal-specific allergic responses in human patients were identified, collected, and analyzed. The information obtained from these articles was then used to compile an exhaustive list of distinctive dermal/ocular, respiratory, gastrointestinal, and systemic hypersensitivity responses associated with metal allergy. Each of these disease variants is discussed briefly within this review, wherein specific metals implicated in each response type are identified, underlying immunological mechanisms are summarized, and major clinical presentations of each reaction are described.Abbreviations: ACD: allergic contact dermatitis, AHR: airway hyperreactivity, ASIA: autoimmune/ autoinflammatory syndrome induced by adjuvants, BAL: bronchoalveolar lavage, CBD: chronic beryllium disease, CTCL: cutaneous T-cell lymphoma, CTL: cytotoxic T-Lymphocyte, DRESS: drug reaction with eosinophilia and systemic symptoms, GERD: gastro-esophageal reflux disease, GI: gastrointestinal, GIP: giant cell interstitial pneumonia, GM-CSF: granulocyte macrophage-colony stimulating factor, HMLD: hard metal lung disease, HMW: high molecular weight, IBS: irritable bowel syndrome, Ig: immunoglobulin, IL: interleukin, LMW: low molecular weight, PAP: pulmonary alveolar proteinosis, PPE: personal protective equipment, PRR: pathogen recognition receptor, SLE: systemic lupus erythematosus, SNAS: systemic nickel allergy syndrome, Th: helper T-cell, UC: ulcerative colitis, UV: ultraviolet.

Disease Burden and Unmet Need in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic, progressive, type 2 inflammatory disease of increasing prevalence, characterized by symptoms of dysphagia and reduced quality of life. A dysregulated type 2 immune response to food and aeroallergen leads to barrier dysfunction, chronic esophageal inflammation, remodeling, and fibrosis. Patients with EoE have impaired quality of life because of dysphagia and other symptoms. They may also suffer social and psychological implications of food-related illness and expensive out-of-pocket costs associated with treatment. Disease burden in EoE is often compounded by the presence of comorbid type 2 inflammatory diseases. Current conventional treatments include elimination diet, proton pump inhibitors, and swallowed topical corticosteroids, as well as esophageal dilation in patients who have developed strictures. These treatments demonstrate variable response rates and may not always provide long-term disease control. There is an unmet need for long-term histologic, endoscopic, and symptomatic disease control; for targeted therapies that can normalize the immune response to triggers, reduce chronic inflammation, and limit or prevent remodeling and fibrosis; and for earlier diagnosis, defined treatment outcomes, and a greater understanding of patient perspectives on treatment. In addition, healthcare professionals need a better understanding of the patient perspective on disease burden, the disconnect between symptoms and disease activity, and the progressive nature of EoE and the need for continuous monitoring and maintenance treatment. In this review, we explore the progression of disease over the patient's lifespan, highlight the patient perspective on disease, and discuss the unmet need for effective long-term treatments.

Molecules involved in the development of Barrett's esophagus phenotype in chronic eosinophilic esophagitis

This paper aims to investigate the molecules involved in development of Barrett's esophagus (BE) in human eosinophilic esophagitis (EoE). Histopathological, immunohistochemical, real-time PCR Immuno blot, and ELISA analyses are performed to identify the signature genes and proteins involved in the progression of BE in EoE. We detected characteristic features of BE like intermediate columnar-type epithelial cells, induced BE signature genes like ErbB3, CDX1, ErbB2IP in the esophageal mucosa of patients with EoE. In addition, we had observed several BE-associated proteins such as TFF3, p53 and the progression markers like EGFR, p16, MICA, MICB, and MHC molecules in esophageal biopsies of patients with chronic EoE. Interestingly, we also detected mucin-producing columnar cells and MUC-2, MUC-4, and MUC5AC genes and proteins along with induced IL-9 in patients with chronic EoE. A strong correlation of IL-9 with mucin genes is observed that implicated a possible role for IL-9 in the transformation of esophageal squamous epithelial cells to columnar epithelial cells in patients with EoE. These findings indicate that IL-9 may have an important role in BE development in patients with chronic EoE. We also discovered that IL-9 stimulates mucin-producing and barrier cell transcripts and proteins such CK8/18, GATA4, SOX9, TFF1, MUC5AC, and tight junction proteins in primary esophageal epithelial cells when exposed to IL-9. Taken together, these findings provide evidence that indeed IL-9 has a role in the initiation and progression of BE characteristics like development of mucin-producing columnar epithelial cells in patients with chronic EoE.NEW & NOTEWORTHY Intermediate columnar-type epithelial cells are observed in biopsies of patients with EoE. Induced BE signature genes (CK8/18, CDX1 GATA4, SOX9, and Occludin) were observed in patients with chronic EoE. Induction of IL-9 and its correlation with eosinophils mucin-producing genes and proteins was observed in patients with EoE. Induced IL-9 may be responsible for the development of BE in patients with chronic EoE.

Barrier Impairment and Type 2 Inflammation in Allergic Diseases: The Pediatric Perspective

Allergic diseases represent a global burden. Although the patho-physiological mechanisms are still poorly understood, epithelial barrier dysfunction and Th2 inflammatory response play a pivotal role. Barrier dysfunction, characterized by a loss of differentiation, reduced junctional integrity, and altered innate defence, underpins the pathogenesis of allergic diseases. Epithelial barrier impairment may be a potential therapeutic target for new treatment strategies Up now, monoclonal antibodies and new molecules targeting specific pathways of the immune response have been developed, and others are under investigation, both for adult and paediatric populations, which are affected by atopic dermatitis (AD), asthma, allergic rhinitis (AR), chronic rhinosinusitis with nasal polyps (CRSwNP), or eosinophilic esophagitis (EoE). In children affected by severe asthma biologics targeting IgE, IL-5 and against IL-4 and IL-13 receptors are already available, and they have also been applied in CRSwNP. In severe AD Dupilumab, a biologic which inhibits both IL-4 and IL-13, the most important cytokines involved in inflammation response, has been approved for treatment of patients over 12 years. While a biological approach has already shown great efficacy on the treatment of severe atopic conditions, early intervention to restore epithelial barrier integrity, and function may prevent the inflammatory response and the development of the atopic march.

Peripheral markers of allergen-specific immune activation predict clinical allergy in eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a T-cell-mediated disease that is caused by specific foods and results in esophageal dysfunction. Existing allergy testing modalities are not helpful when attempting to identify EoE-causal foods necessitating empiric food elimination and recurrent endoscopy. The goal of this study was to identify and compare allergen-specific immune features that can be assayed in a minimally invasive manner to predict clinical food allergy in EoE.

METHODS

We obtained blood samples from control subjects (n = 17), subjects with clinical EoE milk allergy (n = 17), and subjects with immunoglobulin E-mediated milk allergy (n = 9). We measured total and milk-specific plasma immunoglobulin G (IgG)4 levels and peripheral memory CD4⁺ T helper (T_H ) cell proliferation and cytokine production after stimulation with endotoxin-depleted milk proteins. Sensitivity and specificity for predicting clinical EoE milk allergy were calculated and compared between approaches.

RESULTS

Total and milk-specific IgG4 levels were not significantly different between control subjects and subjects with clinical EoE milk allergy. Stimulation with milk proteins caused T_H lymphocytes from subjects with clinical EoE milk allergy to proliferate more (%P1 of 38.3 ± 4.6 vs. 12.7 ± 2.8, p < 0.0001), and produce more type 2 cytokines (%IL-4⁺ of 33.7 ± 2.8 vs. 6.9 ± 1.6, p < 0.0001) than cells from control subjects. Milk-dependent memory T_H -cell proliferation (sensitivity and specificity of 88% and 82%, respectively) and interleukin 4 (IL-4) production (sensitivity and specificity of 100%) most strongly predicted clinical EoE milk allergy.

CONCLUSIONS

Peripheral markers of allergen-specific immune activation may be useful in identifying EoE-causal foods. Assaying milk-dependent IL-4 production by circulating memory T_H lymphocytes most accurately predicts clinical EoE milk allergy.

Gene therapy for a murine model of eosinophilic esophagitis

BACKGROUND

Eosinophils are specialized granulocytic effector cells that store and release highly active mediators used in immune defense. Eosinophils are also implicated in the pathogenesis of allergic disorders, including eosinophilic esophagitis (EoE), a chronic disorder characterized by infiltration of eosinophils into the esophagus and release of mediators that damage tissue, resulting in gastrointestinal morbidity, food impaction, and dysphagia. Treatment with elimination diets and/or topical corticosteroid therapy slow disease progression, but are complicated by adverse effects, limited compliance, and loss of response to therapy. We hypothesized that a single administration of an adeno-associated virus (AAV) coding for an anti-eosinophil monoclonal antibody that induces eosinophil clearance (anti-Siglec-F) would treat on a persistent basis a murine model of EoE.

METHODS

A mouse model of peanut-induced EoE that mimics the human disease was established by sensitization and challenge with peanut extract. After challenge, these mice exhibited an EoE phenotype demonstrated by elevated levels of blood eosinophils, infiltration of eosinophils in the esophagus with associated esophageal remodeling and food impaction.

RESULTS

The mice were treated with a single intravenous administration (10¹¹ genome copies) of AAVrh.10mAnti-Eos, a serotype rh.10 AAV vector coding for an anti-Siglec-F monoclonal antibody. Vector administration resulted in persistent, high levels of anti-Siglec-F antibody expression. Administration of AAVrh.10mAnti-Eos to the mouse model of EoE reduced blood (P < 0.02) and esophageal eosinophil numbers (P < 0.002) protected from esophageal tissue remodeling and minimized food impaction.

CONCLUSION

These results suggest that a single treatment with AAVrh.10mAnti-Eos has the potential to provide persistent therapeutic benefit to patients with EoE.

Eosinophilic esophagitis: an interdisciplinary clinical problem

Eosinophilic esophagitis is a newly described entity of increasing incidence. Previously thought to be a variation of gastroesophageal reflux disease, now it becomes well known among gastroenterologists, allergologists, paediatricians and pathologists. Aetiology of the disease is strongly correlated with atopic and allergic disorders but exact pathogenesis and cellular mechanisms of inflammatory process in the esophagus are still unknown. Diagnostic criteria have been described but diagnostic tools are still in the research and improvement phase. Clinical manifestation varies considerably between age groups, which causes a delay in the course of diagnosis due to improperly recognized symptoms. Since eosinophilic esophagitis is a chronic disease without a tendency to be self-limiting, delayed diagnosis may lead to complications associated with oesophageal tissue remodelling. Some forms of treatment are approved and of great therapeutical value, nevertheless clinical trials of new medications provide new possibilities. Therefore, many questions regarding eosinophilic esophagitis arise and are still unanswered.

Clonally expanded, GPR15-expressing pathogenic effector TH2 cells are associated with eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an allergic disorder characterized by the recruitment of eosinophils to the esophagus, resulting in chronic inflammation. We sought to understand the cellular populations present in tissue biopsies of patients with EoE and to determine how these populations are altered between active disease and remission. To this end, we analyzed cells obtained from esophageal biopsies, duodenal biopsies, and peripheral blood of patients with EoE diagnosed with active disease or remission with single-cell RNA and T cell receptor (TCR) sequencing. Pathogenic effector TH2 (peTH2) cells present in the esophageal biopsies of patients with active disease expressed distinct gene signatures associated with the synthesis of eicosanoids. The esophageal tissue-resident peTH2 population also exhibited clonal expansion, suggesting antigen-specific activation. Peripheral CRTH2+CD161- and CRTH2+CD161+ memory CD4+ T cells were enriched for either a conventional TH2 phenotype or a peTH2 phenotype, respectively. These cells also exhibited substantial clonal expansion and convergence of TCR sequences, suggesting that they are expanded in response to a defined set of antigens. The esophagus-homing receptor GPR15 was up-regulated by peripheral peTH2 clonotypes that were also detected in the esophagus. Finally, GPR15+ peTH2 cells were enriched among milk-reactive CD4+ T cells in patients with milk-triggered disease, suggesting that these cells are an expanded, food antigen-specific population with enhanced esophagus homing potential.

Dupilumab suppresses type 2 inflammatory biomarkers across multiple atopic, allergic diseases

BACKGROUND

Type 2 inflammation is common in numerous atopic/allergic diseases and can be identified by elevated biomarker levels. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4 and interleukin-13, key and central drivers of type 2 inflammation.

OBJECTIVE

Assessment of dupilumab effect on type 2 inflammatory biomarkers in atopic dermatitis (AD), asthma, chronic rhinosinusitis with nasal polyps (CRSwNP) and eosinophilic esophagitis (EoE).

METHODS

Data were extracted from three randomized placebo-controlled trials of dupilumab in AD (NCT02277743, N = 671; NCT02277769, N = 708; NCT02260986, N = 740); and one each in asthma (NCT02414854, N = 1902); CRSwNP (NCT02898454, N = 448); and EoE (NCT02379052, N = 47). Biomarkers assessed were serum thymus and activation-regulated chemokine (TARC), plasma eotaxin-3, serum total immunoglobulin E (IgE), serum periostin and blood eosinophil count.

RESULTS

Dupilumab versus placebo significantly suppressed most type 2 inflammatory biomarker levels across all studies/indications where data were assessed. Reductions in serum TARC, plasma eotaxin-3 and serum periostin occurred rapidly, whereas reductions in serum total IgE were more gradual. Across diseases, at the end of treatment, median percentage change from baseline in TARC levels ranged from -24.8% to -88.6% (placebo +2.6% to -53.6%); -38.2% to -51.5% (placebo +8.3% to -0.16%) in eotaxin-3; -24.8% to -76.7% (placebo +8.3% to -4.4%) in total IgE; and -13.6% to -41.1% (placebo +10.1% to -6.94%) in periostin levels. Blood eosinophil responses to dupilumab varied by disease, with minimal changes in AD in the SOLO studies (median percentage change from baseline to end of treatment: 0% [95% CI: -15.8, 0]); transient increases followed by decreases to below-baseline levels in asthma (-14.6% [-20.0, -7.7]) and CRSwNP (-29.4% [-40.0, -16.3]); and significant decreases in EoE (-50.0% [-50.0, -33.3]).

CONCLUSION AND CLINICAL RELEVANCE

Dupilumab reduced levels of type 2 biomarkers across clinical studies in patients with AD, asthma, CRSwNP and EoE.

Innate Immune Regulation of Dermatitis

Dermatitis encompasses a spectrum of inflammatory skin disorders with aberrant immune responses classified as type 1, type 2, and/or type 3. Major advances in the understanding of the pathogenesis of atopic dermatitis (AD) have shed new light on how innate immune responses critically regulate type 2 inflammation and itch. This article highlights the diverse ways by which type 2 immune cells regulate diseases beyond AD. The discovery of human Mas-related G protein-coupled receptor X2 on mast cells has revealed novel T cell-independent and immunoglobulin E-independent mechanisms of allergic contact dermatitis-associated and urticarial itch, respectively.

Dietary Management of Eosinophilic Esophagitis: Tailoring the Approach

Eosinophilic esophagitis (EoE) is a unique form of non-immunoglobulin E-mediated food allergy, restricted to the esophagus, characterized by esophageal eosinophil-predominant inflammation and dysfunction. The diagnosis requires an esophago-gastroduodenoscopy with esophageal biopsies demonstrating active eosinophilic inflammation with 15 or more eosinophils/high-power field, following the exclusion of alternative causes of eosinophilia. Food allergens trigger the disease, withdairy/milk, wheat/gluten, egg, soy/legumes, and seafood the most common. Therapeutic strategies comprise dietary restrictions, proton pump inhibitors, topical corticosteroids, biologic agents, and esophageal dilation when strictures are present. However, avoidance of trigger foods remains the only option targeting the cause, and not the effect, of the disease. Because EoE relapses when treatment is withdrawn, dietary therapy offers a long-term, drug-free alternative to patients who wish to remain off drugs and still be in remission. There are currently multiple dietary management strategies to choose from, each having its specific efficacy, advantages, and disadvantages that both clinicians and patients should acknowledge. In addition, dietary regimens should be tailored around each individual patient to increase the chance of tolerability and long-term adherence. In general, liquid elemental diets devoid of antigens and elimination diets restricting causative foods are valuable options. Designing diets on the basis of food allergy skin tests results is not reliable and should be avoided. This review summarizes the most recent knowledge regarding the clinical use of dietary measures in EoE. We discussed endpoints, rationale, advantages and disadvantages, and tailoring of diets, as well as currently available dietary regimens for EoE.

Antifibrotic Effects of the Thiazolidinediones in Eosinophilic Esophagitis Pathologic Remodeling: A Preclinical Evaluation

Eosinophilic esophagitis (EoE) is a T-helper 2 (Th2), eosinophilic disease associated with pathologic tissue remodeling that leads to end-organ dysfunction. During early-stage disease, inflammation and subepithelial fibrosis are coupled and reversible, but in late-stage or therapy-resistant disease, there can be uncoupling of these features with progressive esophageal rigidity and strictures contributing to clinical dysphagia and food impactions. No current pharmacotherapeutic interventions directly target esophageal fibrosis. Based on the ability of the thiazolidinediones (TZD) to regulate intestinal and hepatic fibrosis, we tested the antifibrotic effects of the TZDs, rosiglitazone and pioglitazone, in preclinical studies using primary human esophageal fibroblasts.

Immunohistochemical expression of filaggrin is decreased in proton pump inhibitor non-responders compared with proton pump inhibitor responders of eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is an allergic gastrointestinal disease that features eosinophilic infiltration of esophageal mucosa, but the role of barrier dysfunction of the epithelium in its pathogenesis remains to be elucidated. Clinically, EoE is divided into proton pump inhibitor-non-responders (PPI-NR) and PPI-responders (PPI-R). Our main aims were to investigate the differences of expression of epidermal differential complex (EDC) proteins and desmoglein that are considered to play important roles in formation of the epidermal skin barrier between these two conditions and to seek the usefulness of the differences in pathological diagnosis. Conventional histopathological findings and allergic background were also compared.

METHODS

Twenty-nine PPI-NR and 44 PPI-R were recruited, and 35 reflux esophagitis patients were also enrolled. After clinical information and histopathological findings were reviewed, immunohistochemical expression of EDC proteins (filaggrin, loricrin, and involucrin) and desmoglein in all three groups were examined and semi-quantitatively scored.

RESULTS

Regarding allergic conditions, the prevalence of asthma was significantly higher in PPI-NR than in PPI-R. Other allergic conditions showed no differences. Histopathological findings did not exhibit the statistical difference between PPI-NR and PPI-R. However, immunostaining score of filaggrin in PPI-NR was significantly lower than in PPI-R, although the expressions of involucrin, loricrin and desmoglein demonstrated no differences.

CONCLUSIONS

The results suggest a role of reduced filaggrin expression in the difference of effectiveness of PPI treatment between PPI-NR and PPI-R. Moreover, immunohistochemical determination of filaggrin expression in EoE patients could be informative in the clinical decision of how to treat the patients.

Gastrointestinal immunopathology of food protein-induced enterocolitis syndrome and other non-immunoglobulin E-mediated food allergic diseases

OBJECTIVE

To provide a concise summary of the current literature regarding gastrointestinal immunopathology of food protein-induced enterocolitis syndrome (FPIES) and other non-immunoglobulin E (IgE)-mediated food allergic diseases.

DATA SOURCES

Data were extracted from PubMed, MEDLINE, and ScienceDirect databases.

STUDY SELECTIONS

Original articles, review articles, and guidelines published in the past 5 years in peer-reviewed journals were first summarized. The original articles cited were then reviewed and relevant results were extracted.

RESULTS

Patients with FPIES and non-IgE-mediated food allergic diseases developed vomiting, diarrhea, and food aversion expelled food allergen from their bodies. Aside from T helper type 2 (T_H2) immunity, T_H1, T_H17, innate immunity, and epithelial mucosal barrier defect were also found to be important in the pathogenesis. Eosinophils, widely identified in the biopsy samples, were key players or were late-recruited cells for tissue repairs in those diseases. Intestinal dysbiosis and their metabolites stimulated enterochromaffin cells or enteroendocrine cells to produce serotonin, interfering with intestinal motility and subsequently affecting brain function. FPIES and non-IgE-mediated food allergic diseases were likely part of the atopic march. Allergic inflammation in intestinal mucosa might result in subsequent inflammation in the airway mucosa, suggesting the theory of "one mucosa, one disease."

CONCLUSION

The immune responses of FPIES and non-IgE-mediated food allergic diseases were not limited to the gastrointestinal tract, but also trigger wider inflammatory responses beyond it. Further research will be required to determine the systemic effect and intestinal microbiome of those diseases.

Eosinophilic esophagitis: novel concepts regarding pathogenesis and clinical manifestations

Eosinophilic esophagitis is a chronic disease whose incidence and prevalence are increasing, based on a genetic-driven interaction between environment and immune system. Several gene loci involved in the development of the disease have been identified. A two-step mechanism has been hypothesized: a thymic stromal lymphopoietin-induced allergic sensitization followed by upregulation of CAPN14-related esophageal-specific pathways. Environment seems to have a larger effect than genetic variants. Factors that could play a role are allergens, drugs, colonizing bacteria and possibly Helicobacter Pylori infection. Acting on these modifiable risk factors may be a tool to prevent the disease. EoE is characterized by a typical eosinophilic infiltrate limited to the esophageal epithelium, supported by a Th2-mediated immune response, found in other atopic conditions. The key of the pathogenesis is the disfunction of the epithelial barrier which allow the interaction between allergens and inflammatory cells. Eosinophilic-predominant inflammation leads to the typical wall remodeling, histologically characterized by epithelial and smooth muscle hyperplasia, lamina propria fibrosis and neo-angiogenesis. These alterations find their clinical expression in the pattern of symptoms: dysphagia, food impaction, chest pain, heartburn.

The eosinophilic esophagitis and IgG4-related disease involving the esophagus

The study of eosinophilic esophagitis has become a dynamic field with an evolving understanding of the pathogenesis, diagnosis, and treatment. Immunoglobulin G4 (IgG4)-related disease exhibits systemic involvement but very rarely involves the esophagus. The article presents a clinical case: the history of ulcer and stricture of the esophagus in a young man of 17 years. The patient was finally diagnosed with IgG4-related and eosinophilic esophagitis and showed a good response to corticosteroid therapy. We herein report a rare case of dysphagia associated with IgG4-related disease and eosinophilic. We presented a review of modern data on the relationship of eosinophilic esophagitis and pathological IgG4-response.

Eosinophilic Esophagitis Occurring After Switching to Ultra-Pasteurized Milk: Coincidence or Unrecognized Etiologic Trigger?

Eosinophilic esophagitis (EoE) is an increasingly common cause of dysphagia, food impaction, and abdominal pain. Cow’s milk is a major trigger of EoE, but the exact mechanism remains unclear. We present a case of EoE occurring shortly after switching from regularly pasteurized milk to ultra-pasteurized milk.

Functional Dyspepsia and Food: Immune Overlap with Food Sensitivity Disorders

PURPOSE OF REVIEW

Functional dyspepsia (FD) is a chronic functional gastrointestinal disorder characterised by upper gastrointestinal symptoms. Here, we aimed to examine the evidence for immune responses to food in FD and overlap with food hypersensitivity conditions.

RECENT FINDINGS

A feature of FD in a subset of patients is an increase in mucosal eosinophils, mast cells, intraepithelial cytotoxic T cells and systemic gut-homing T cells in the duodenum, suggesting that immune dysfunction is characteristic of this disease. Rates of self-reported non-celiac wheat/gluten sensitivity (NCW/GS) are higher in FD patients. FD patients commonly report worsening symptoms following consumption of wheat, fermentable oligosaccharides, disaccharides, monosaccharides, or polyols (FODMAPs), high-fat foods and spicy foods containing capsaicin. Particularly, wheat proteins and fructan in wheat may drive symptoms. Immune mechanisms that drive responses to food in FD are still poorly characterised but share key effector cells to common food hypersensitivities including non-IgE-mediated food allergy and eosinophilic oesophagitis.

Cell-by-cell deciphering of T cells in allergic inflammation

Technical advances in single-cell RNA sequencing (scRNA-seq) render it possible to examine the transcriptomes of single cells in patients with allergic inflammation with high resolution in the context of their specific microenvironment, treatment, and disease status. Using a recently published scRNA-seq study of tissue T cells as an example, we introduce the major pipeline steps, illustrate the options of scRNA-seq platforms, summarize new knowledge gained from this study, and provide directions for future research. The presented scRNA-seq study elucidated the T-cell heterogeneity present in an allergic inflammatory tissue focused on eosinophilic esophagitis, a prototypic, chronic, allergic disease, which provided a unique opportunity to probe the pathogenesis of allergic inflammation at the tissue level through readily available endoscopically procured biopsy specimens. scRNA-seq analysis identified 8 populations of CD3⁺ T cells and defined 2 disease-specific populations of CD3⁺CD4⁺ T cells, including a markedly activated type 2 cytokine-producing pathogenic cell population distinguished by expression of the short-chain fatty acid receptor free fatty acid receptor 3 and a population of regulatory T cells. In addition to presenting and interpreting new findings within the prior literature, we postulate about future single-cell next-generation sequencing platforms in this burgeoning field.

Hypersensitivity Reactions: An Everyday Occurrence in Pediatric Allergy Clinics

The explanation of hypersensitivity reactions has long relied on the classification of Gell and Coombs, originally proposed in the 1960s. However, their concepts were predated by other authors by at least 50 years. A 21st century pediatric allergy clinic provides multiple examples of these basic concepts on a daily basis. We review classic and less classic examples of the original criteria, highlight where current disease pathophysiology does not always fit the original model, and provide updated language for common and uncommon immunologically driven hypersensitivity diseases.

Increased number of regulatory T cells in esophageal tissue of patients with eosinophilic esophagitis in comparison to gastro esophageal reflux disease and control groups

BACKGROUND

Eosinophilic esophagitis (EoE) is a primarily polygenic allergic disorder. Although most patients have IgE sensitization, it seems that non-IgE mediated responses mainly contribute to the pathogenesis of EoE. Regulatory T cells (Tregs) may have an important role in allergies. There are limited data on the association of Tregs and EoE. In this study, we enumerated and compared T lymphocytes and Tregs in esophageal tissue of patients with EoE, gastroesophageal reflux disease (GERD) and normal controls.

METHODS

Ten patients with EoE, ten patients with GERD and eight normal controls were included. Immunohistochemistry staining was used to enumerate T lymphocytes and Tregs. CD3+ cells were considered as T cells and FOXP3+, CD3+ cells were considered as Tregs. T cells and Tregs were counted in 10 high power fields (HPF) (×400) for each patient and the average of 10 HPFs was recorded.

RESULTS

The mean±SEM of Tregs in esophageal tissue of patients with EoE (10.90±2.14cells/HPF) was significantly higher than the GERD (2.77±0.66cells/HPF) and control groups (0.37±0.08cells/HPF) (P<0.001). Additionally, the mean±SEM of T lymphocytes in esophageal tissue of patients with EoE (24.39±3.86cells/HPF) were increased in comparison to the GERD (10.07±2.65cells/HPF) and control groups (3.17±0.93cells/HPF) (P<0.001).

CONCLUSION

There is an increase in the number of esophageal T lymphocytes and regulatory T cells in patients with EoE compared to the GERD and control groups.

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.

Human eosinophils and mast cells: Birds of a feather flock together

While the origin of the phrase "birds of a feather flock together" is unclear, it has been in use for centuries and is typically employed to describe the phenomenon that people with similar tastes or interests tend to seek each other out and congregate together. In this review, we have co-opted this phrase to compare innate immune cells of related origin, the eosinophil and mast cell, because they very often accumulate together in tissue sites under both homeostatic and inflammatory conditions. To highlight overlapping yet distinct features, their hematopoietic development, cell surface phenotype, mediator release profiles and roles in diseases have been compared and contrasted. What emerges is a sense that these two cell types often interact with each other and their tissue environment to provide synergistic contributions to a variety of normal and pathologic immune responses.

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.

Comparison of comorbid diagnoses in children with and without eosinophilic esophagitis in a large population

BACKGROUND

Previous reports suggest a higher prevalence of comorbid diseases in patients with eosinophilic esophagitis (EoE), although few have systematically quantified comorbidities in pediatric patients.

OBJECTIVE

To define the rate of comorbid diagnoses in pediatric EoE patients compared with rates in those without EoE.

METHODS

Retrospective cross-sectional review of electronic medical records for patients seen in a single large pediatric primary care network between January 2007 and December 2016 (n = 456,148). International Classification of Diseases, Ninth and Tenth Revision codes were used to determine prevalence rates for coexisting diagnoses.

RESULTS

A total of 428 patients held a diagnosis for EoE. Significant differences in rate of comorbid diseases included allergic rhinoconjunctivitis (60.0% of EoE cohort vs 17.4% of non-EoE cohort, P < .0001); asthma (59.8% of EoE, 21.4% of non-EoE, P < .0001); atopic dermatitis (17.8% of EoE, 6.6% of non-EoE, P < .0001); adrenal insufficiency (2.6% of EoE, 0.4% of non-EoE, P < .0001); autism spectrum disorder (7.5% of EoE, 1.9% of non-EoE, P < .0001); celiac disease (5.6% of EoE, 0.9% of non-EoE, P < .0001); connective tissue diseases (1.4% of EoE, 0.1% of non-EoE, P < .0001); cystic fibrosis (0.9% of EoE, 0.05% of non-EoE, P < .0001); inflammatory bowel disease (0.7% of EoE, 0.2% of non-EoE, P = .03); type 1 diabetes mellitus (1.2% of EoE, 0.3% of non-EoE, P = .0069).

CONCLUSION

Children with EoE have markedly higher rates of both atopic and non-atopic diseases compared with children without EoE. These associations have important implications for comprehensive EoE care and future research regarding associated disease mechanisms.

Eosinophilic Esophagitis Is a Late Manifestation of the Allergic March

BACKGROUND

The allergic march describes the natural history of allergic conditions as they develop during childhood. Eosinophilic esophagitis (EoE) is a chronic allergic inflammatory disease that can be triggered by specific foods. Despite its allergic pathophysiology, the epidemiologic relationship between EoE and established members of the allergic march is unknown.

OBJECTIVE

We sought to determine whether EoE meets epidemiologic criteria for being considered a member of the allergic march.

METHODS

Using a primary care birth cohort of 130,435 children, we determined the natural histories of atopic dermatitis (AD), IgE-mediated food allergy (IgE-FA), asthma, EoE, and allergic rhinitis (AR) in individual patients. We then performed case-control analyses to establish the extent that existing allergic conditions influence the rate of subsequent EoE diagnosis.

RESULTS

A total of 139 children developed EoE during the observation period (prevalence of 0.11%). The peak age of EoE diagnosis was 2.6 years, as compared with 0.3 years, 1 year, 1.1 years, and 2.1 years for AD, IgE-FA, asthma, and AR, respectively. The presence of AD (hazard ratio [HR] 3.2, 95% confidence interval [CI] 2.2-4.6), IgE-FA (HR 9.1, 95% CI 6.5-12.6), and asthma (HR 1.9, 95% CI 1.3-2.7) was independently and cumulatively associated with subsequent EoE diagnosis. The presence of AR was associated with subsequent EoE diagnosis (HR 2.8, 95% CI 2.0-3.9), and the presence of EoE was associated with subsequent AR diagnosis (HR 2.5, 95% CI 1.7-3.5).

CONCLUSIONS

Allergic comorbidities are positively associated with EoE diagnosis. Together, our findings suggest that EoE is a late manifestation of the allergic march.

Specific IgG4 antibodies to cow's milk proteins in pediatric patients with eosinophilic esophagitis

BACKGROUND

Allergen-specific IgG₄ (sIgG₄) antibodies are often associated with tolerance, but sIgG₄ antibodies to causally relevant foods have been reported recently in adults with eosinophilic esophagitis (EoE). Prevalence and levels of food sIgG₄ are not well established in the general pediatric population.

OBJECTIVE

We sought to investigate serum food sIgG₄ with component diagnostics in children with EoE and children from an unselected birth cohort and to explore the effects of sex, age, and milk consumption on sIgG₄ levels.

METHODS

Sera from 71 pediatric patients with EoE and 210 early adolescent children from an unselected birth cohort (Project Viva) were assayed for sIgG₄ and specific IgE (sIgE) to major cow's milk (CM) proteins (α-lactalbumin, β-lactoglobulin, and caseins) and to wheat, soy, egg, and peanut proteins.

RESULTS

In the EoE cohort high-titer sIgG₄ (≥10 μg/mL) to CM proteins was more common than in control sera and achieved odds ratios for EoE ranging from 5.5 to 8.4. sIgE levels to CM proteins were mostly 4 IU/mL or less in patients with EoE, such that sIgG₄/sIgE ratios were often 10,000 or greater. When adjusted for age and milk consumption, high-titer sIgG₄ to CM proteins was strongly associated with EoE, with an odds ratio of greater than 20 to all 3 CM proteins in boys.

CONCLUSIONS

sIgG₄ to CM proteins are common and high titer in children with EoE. Although it is not clear that this response is pathogenic, sIgG₄ levels imply that these antibodies are an important feature of the local immune response that gives rise to EoE.

Is eosinophilic esophagitis an equivalent of pollen allergic asthma? Analysis of biopsies and therapy guided by component resolved diagnosis

BACKGROUND

Eosinophilic esophagitis (EoE) is characterized by esophageal dysfunction and, histologically, by eosinophilic inflammation. There is not a clear etiologic treatment. Biopsies analysis using plant histology methods may show callose and pollen tubes in the esophageal mucosa. Component-resolved diagnosis (CRD) with microarrays could detect possible allergens involved and indicate an elimination diet and allergen immunotherapy (AIT).

METHODS

One hundred and twenty-nine patients with EoE were tested for environmental and food allergens. CRD, histological and botanical analysis were performed. Clinical scores and endoscopic biopsy were performed every six months for three years. Fifty healthy patients, 50 asthmatics due to pollen, and 53 celiac disease patients were included as comparison groups. CRD-directed AIT was administered in 91 EoE patients and elimination diet in 140 patients (87 EoE and all 53 CD patients).

RESULTS

CRD detected allergen hypersensitivity in 87.6% of patients with EoE. The predominant allergens were grass group 1 (55%), lipid transfer proteins (LTP) of peach and mugwort, hazelnuts and walnuts. Callose from pollen tubes was found in 65.6% of biopsies. After CRD-guided elimination diet and/or AIT, 101 (78.3%) EoE patients showed significant clinical improvement (p<0.017) and 97 (75.2%) were discharged (negative biopsy, no symptoms, no medication) without relapse. AIT-treated patients had better outcomes (odds ratio 177.3, 95% CI 16.2-1939.0).

CONCLUSION

CRD-directed AIT and/or elimination diet was efficient in treating EoE patients and was well tolerated.

Eosinophilic Esophagitis in Children and Adults

Adults and children with eosinophilic esophagitis (EoE) have distinct clinical and endoscopic presentations. Recognition of clinical signs, along with laboratory and endoscopic findings, is critical for the identification of patients with EoE because delay in diagnosis has been associated with esophageal remodeling and stricture formation. Clinical presentation varies considerably between adults and children. This is less due to differences in the disease and more due to patient differences. This article describes the similarities and differences in clinical presentation of children and adults with EoE, including areas of epidemiology, clinical and endoscopic presentation, pathophysiology, and treatment.

Elevated expression of activated TH2 cells and milk-specific TH2 cells in milk-induced eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is an allergic inflammatory disease that is triggered by food allergens and characterized by progressive esophageal dysfunction. Esophageal biopsy specimens are characterized by eosinophilia and expression of T_H2 cytokines.

OBJECTIVE

To ascertain whether T_H2 cells can exist in the peripheral blood in patients with milk-induced EoE.

METHODS

Peripheral blood mononuclear cells from 20 children with milk-induced EoE were collected during active EoE (EoE-A) while consuming milk and inactive EoE (EoE-I) while not consuming milk, and 8 healthy patients without EoE were used as controls. The samples were analyzed for T-cell phenotype, including intracellular cytokines before and after incubation with milk antigens and assessed by flow cytometry.

RESULTS

We found a significant increase in CD4⁺ T_H2 cells in the peripheral blood of patients with EoE-A compared with the controls. Furthermore, we observed a significant mean (SD) increase in the activation marker of CD154⁺ T cells (0.17% [0.047^%]) in patients with EoE-A compared with control patients (0.034% [0.007%]) and EoE-I (0.025% [0.008]). These CD4⁺ T cells expressed significantly increase levels of T_H2 cytokines (interleukins 4, 5, and 13) compared with the EoE-I and control groups. CD3⁺CD4⁺CD154⁺IL-5⁺ cells were significantly increased by milk antigens in both milk-induced EoE-A (0.050% [0.008%] to 0.079% [0.017%]) and EoE-I (0.0045% [0.002%] to 0.014% [0.008%]) compared with the controls (0.008% [0.003%] to 0.003% [0.001%]).

CONCLUSION

Our findings indicate that in EoE peripheral T cells have specific activation to milk allergens.

Creating a multi-center rare disease consortium - the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR)

 Eosinophilic gastrointestinal disorders (EGIDs) affect various segments of the gastrointestinal tract. Since these disorders are rare, collaboration is essential to enroll subjects in clinical studies and study the broader population. The Rare Diseases Clinical Research Network (RDCRN), a program of the National Center for Advancing Translational Sciences (NCATS), funded the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR) in 2014 to advance the field of EGIDs. CEGIR facilitates collaboration among various centers, subspecialties, patients, professional organizations and patient-advocacy groups and includes 14 clinical sites. It has successfully initiated two large multi-center clinical studies looking to refine EGID diagnoses and management. Several pilot studies are underway that focus on various aspects of EGIDs including novel therapeutic interventions, diagnostic and monitoring methods, and the role of the microbiome in pathogenesis. CEGIR currently nurtures five physician-scholars through a career training development program and has published more than 40 manuscripts since its inception. This review focuses on CEGIR's operating model and progress and how it facilitates a framework for exchange of ideas and stimulates research and innovation. This consortium provides a model for progress on other potential clinical areas.

Genetics of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic, allergic disease associated with marked mucosal eosinophil accumulation. EoE disease risk is multifactorial and includes environmental and genetic factors. This review will focus on the contribution of genetic variation to EoE risk, as well as the experimental tools and statistical methodology used to identify EoE risk loci. Specific disease-risk loci that are shared between EoE and other allergic diseases (TSLP, LRRC32) or unique to EoE (CAPN14), as well as Mendellian Disorders associated with EoE, will be reviewed in the context of the insight that they provide into the molecular pathoetiology of EoE. We will also discuss the clinical opportunities that genetic analyses provide in the form of decision support tools, molecular diagnostics, and novel therapeutic approaches.

The Prevalence of Eosinophilic Esophagitis in Pediatric Patients with IgE-Mediated Food Allergy

BACKGROUND

Eosinophilic esophagitis (EoE) is an allergic inflammatory disease that is triggered by food allergens and characterized by progressive esophageal dysfunction. Recently, EoE has been identified in patients who underwent oral immunotherapy (OIT) for IgE-mediated food allergy, suggesting an association.

OBJECTIVE

We sought to ascertain whether significant associations exist between IgE-mediated food allergies and EoE.

METHODS

Using the analysis of electronic medical record data and manual chart review, we examined our subspecialty care network of 35,528 children and adolescents to identify and characterize patients with IgE-mediated and EoE food allergy. The most common food allergens were defined, and the prevalence of EoE in patients with IgE-mediated food allergy was determined. Logistic regression was used to measure the extent to which IgE-mediated food allergy to specific foods is associated with EoE.

RESULTS

The most common causes of EoE were milk, soy, egg, grains, and meats, an allergen pattern that is distinct from that of IgE-mediated food allergy. The prevalence of EoE in patients with IgE-mediated food allergy was higher than that reported in the general population (4.7% vs 0.04%). The distribution of IgE-mediated food allergens in patients with EoE was similar to that of the general population, and IgE-mediated allergy to egg (2.27; 1.91-2.64), milk (4.19; 3.52-4.97), or shellfish (1.55; 1.24-1.92) was significantly associated with an EoE diagnosis.

CONCLUSIONS

Our findings support a clinical association between these conditions that has implications for the management of children with food allergy, and particular relevance to patients undergoing OIT.

Lymphocytic oesophagitis, eosinophilic oesophagitis and compound lymphocytic-eosinophilic oesophagitis I: histological and immunohistochemical findings

AIMS

To report four histological-immunohistochemical oesophagitis phenotypes.

METHODS

Oesophageal biopsies from 311 patients were stained with H&E and with CD3, a T cell marker. Additional immunohistochemical stains (n=413) were performed in 77 cases.

RESULTS

Four histological-immunohistochemical oesophagitis phenotypes were recorded: lymphocytic oesophagitis (LyE, ≥40 CD3+ lymphocytes/HPF in CD3 immunostain), eosinophilic oesophagitis (EoE, ≥15 eosinophils/HPF in H&E stain), lymphocytic infiltration (≤39 CD3+/HPF) and compound lymphocytic oesophagitis-eosinophilic oesophagitis (Co LyE-EoE). At index biopsy, 28.3% (n=88) had LyE, 21.2% (n=66) EoE, 10.6% (n=33) Co LyE-EoE and 39.9% (n=124) lymphocytic infiltration. A persistent oesophagitis phenotype was found in 42.5% (37/87) in the first follow-up biopsy, in 34.4% (21/61) in the second follow-up biopsy and in 48.1% (26/54) in the third follow-up biopsy. Using βF1 immunostain, two different surface T cell receptors were detected in LyE and Co Lye-EoE: one having ≥40 βF1+/HPF (βF1+ high) and the other having <39 βF1+/HPF (βF1+ low).

CONCLUSIONS

Based on the literature regarding the significance of intraepithelial lymphocytes (IELs) in the initiation of EoE, we submit that the IEL phenotypes in LyE might differ from those found in EoE as they were unable to elicit the same eosinophilic response. Recent studies disclosed that group 2 innate lymphocytes (ILC2s), enriched in EoE, remain undetected in CD3 immunostain as they lack surface markers for T, B, natural killer (NK) or NK T cells. If ILC2s also participate in the lymphocytic infiltration of EoE, then the frequency of cases with Co LyE-EoE here reported might have been much higher. The four oesophagitis phenotypes described are easy to recognise, provided that the dual staining procedure (H&E-CD3) is implemented.