Utility of a Noninvasive Serum Biomarker Panel for Diagnosis and Monitoring of Eosinophilic Esophagitis: A Prospective Study

Peripheral Blood IL5RA Gene Expression as a Diagnostic Biomarker for Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an allergic inflammatory condition of the esophagus, often diagnosed late because of its challenging symptoms and costly and invasive diagnostic methods.1,2 To address the need for more accessible biomarkers in EoE,3 we aimed to investigate the potential of whole-blood RNA expression as a noninvasive biomarker for diagnosing and monitoring EoE, hypothesizing that genetic signatures in blood could distinguish EoE cases, correlate with disease activity, and predict treatment responses.

Clinical Evaluation of the Adult with Eosinophilic Esophagitis

Adult patients with eosinophilic esophagitis (EoE) typically present with a history of dysphagia for solids, sometimes with additional reflux-like pain and a history of prior food impactions. In contrast to these alarming symptoms, the general appearance and physical examination of adult patients with EoE is in line with apparently healthy individuals. Therefore, the diagnosis is based on a history of solid-food dysphagia and eosinophilic tissue infiltration. Importantly, the increasing prevalence of EoE variants, that is, typical EoE symptoms in the absence of a relevant eosinophilia, and several studies with eosinophil-targeting drugs, call the pathogenic role of eosinophils into question.

Vitamin D Levels as a Potential Modifier of Eosinophilic Esophagitis Severity in Adults

BACKGROUND

Vitamin D deficiency is associated with atopic and immune-mediated diseases but has not been extensively assessed in eosinophilic esophagitis (EoE). We aimed to assess if vitamin D levels in newly diagnosed EoE patients were lower than in non-EoE controls and examine levels in relation to EoE clinical features.

METHODS

This secondary analysis of a prospective cohort study used data and biosamples from adults who underwent outpatient esophagogastroduodenoscopy. Before each procedure, blood was obtained and stored at -80oC. Serum 25-hydroxy-vitamin D3 (25(OH)D3) was measured by ELISA. Levels for cases and controls were compared at baseline. Within cases, 25(OH)D3 levels were compared for clinical, endoscopic, and histologic measures.

RESULTS

We analyzed 40 EoE and 40 non-EoE controls. Mean serum 25(OH)D3 level was slightly lower in EoE patients than controls (30.9 ± 15.3 ng/mL vs. 35.9 ± 15.4; p = 0.15). After controlling for age, sex, and race, adjusted levels were 10.8 ng/mL lower in EoE patients (95% CI: -19.0, -2.5), but 25(OH)D3 deficiency (< 20ng/mL) was similar in cases and controls (20% vs. 15%; p = 0.56). Levels of 25(OH)D3 were not associated with differences in clinical or endoscopic features of EoE, and EREFS and eosinophil counts did not significantly correlate with 25(OH)D3 levels (R of -0.28 [p = 0.08] and - 0.01 [p = 0.93], respectively). 25(OH)D3 levels were lower in EoE cases with lamina propria fibrosis (23.2 ± 9.6 vs. 45.0 ± 17.7; p = 0.03).

CONCLUSIONS

After adjusting for age, sex, and race, 25(OH)D3 levels were lower in EoE cases than controls, but deficiency was not common. 25(OH)D3 levels were generally similar across most EoE disease features.

Identification of CXC Chemokine Receptor 2 (CXCR2) as a Novel Eosinophils-Independent Diagnostic Biomarker of Pediatric Eosinophilic Esophagitis by Integrated Bioinformatic and Machine-Learning Analysis

Background

Eosinophilic esophagitis (EoE) is a complex allergic condition frequently accompanied by various atopic comorbidities in children, which significantly affects their life qualities. Therefore, this study aimed to evaluate pivotal molecular markers that may facilitate the diagnosis of EoE in pediatric patients.

Methods

Three available EoE-associated gene expression datasets in children: GSE184182, GSE 197702, GSE55794, along with GSE173895 were downloaded from the GEO database. Differentially expressed genes (DEGs) identified by "limma" were intersected with key module genes identified by weighted gene co-expression network analysis (WGCNA), and the shared genes went through functional enrichment analysis. The protein-protein interaction (PPI) network and the machine learning algorithms: least absolute shrinkage and selection operator (LASSO), random forest (RF), and XGBoost were used to reveal candidate diagnostic markers for EoE. The receiver operating characteristic (ROC) curve showed the efficacy of differential diagnosis of this marker, along with online databases predicting its molecular regulatory network. Finally, we performed gene set enrichment analysis (GSEA) and assessed immune cell infiltration of EoE/control samples by using the CIBERSORT algorithm. The correlations between the key diagnostic biomarker and immune cells were also investigated.

Results

The intersection of 936 DEGs and 1446 key module genes in EoE generated 567 genes, which were primarily enriched in immune regulation. Following the construction of the PPI network and filtration by machine learning, CXCR2 served as a potential diagnostic biomarker of pediatric EoE with a perfect diagnostic efficacy (AUC = ~1.00) in regional tissue/peripheral whole blood samples. Multiple infiltrated immune cells were observed to participate in disrupting the homeostasis of esophageal epithelium to varying degrees.

Conclusion

The immune-correlated CXCR2 gene was proved to be a promising diagnostic indicator for EoE, and dysregulated regulatory T cells (Tregs)/neutrophils might play a crucial role in the pathogenesis of EoE in children.

Addressing diagnostic dilemmas in eosinophilic esophagitis using esophageal epithelial eosinophil-derived neurotoxin

OBJECTIVES

Eosinophil-derived neurotoxin (EDN) is a viable marker of eosinophilic esophagitis (EoE) disease activity. We studied the utility of measuring EDN from esophageal epithelial brushings for diagnosing EoE, focusing on two scenarios: (1) cases of exclusive distal eosinophilia and (2) cases of discrepancy between endoscopy and histology.

METHODS

Records of patients who underwent esophagogastroduodenoscopy (EGD) with EDN measured via esophageal brushings at Arnold Palmer Hospital for Children in Orlando, Florida from January 2014 to October 2018 were retrospectively reviewed. Demographics, clinical, endoscopic, and histologic data were collected.

RESULTS

We reviewed 231 patient records (66.7% male, mean age 10.3 years, range 1-22 years). EDN values correlated with endoscopic reference score (EREFS) and peak eosinophil count (PEC) (Spearman's rho = 0.756 (p < 0.001) and 0.824 (p < 0.001) respectively). Average PEC, EREFS, and EDN concentrations were higher in patients with active EoE than in controls or patients with EoE in remission (inactive). When grouping patients based on esophageal eosinophilia distribution, EDN mirrored PEC, and EREFS. Patients with exclusive distal eosinophilia had lower EDN concentrations than those with eosinophilia in >1 level of the esophagus (23.8 ± 46.1 mcg/mL vs. 171.3 ± 205.8 mcg/mL respectively, p < 0.001). EDN values were more consistent with EREFS in cases of discrepancies between endoscopic findings and pathology (p < 0.001).

CONCLUSION

EDN measured in esophageal brushing samples reflects disease activity objectively and accurately. It also offers significant value in cases of exclusive distal esophageal eosinophilia and when discrepancies exist between endoscopy and histology.

Non-Invasive and Minimally Invasive Biomarkers for the Management of Eosinophilic Esophagitis beyond Peak Eosinophil Counts: Filling the Gap in Clinical Practice

Eosinophilic esophagitis (EoE) is a chronic esophageal disease that needs lifelong management and follow-up. The diagnosis requires an upper endoscopy with at least one esophageal biopsy demonstrating >15 eosinophils/high-power field, and often occurs with a diagnostic delay of up to ten years, partly due to the absence of valid non-invasive screening tools. In addition, serial upper endoscopies with esophageal biopsies are mandatory to assess the efficacy of any ongoing treatment in patients with EoE. These procedures are invasive, costly, and, when performed without sedation, are often poorly tolerated by patients. Therefore, there is the clinical need to identify reliable non-invasive or minimally invasive biomarkers that could be used to assess disease activity in clinical practice as a surrogate of peak eosinophil counts on esophageal biopsies. This review summarizes evidence on investigational non-invasive or minimally invasive biomarkers for the diagnosis and follow-up of EoE to report on the state of the art in the field and support future research. We discussed eosinophil-derived mediators including eosinophil cationic protein (ECP), eosinophil-derived neurotoxin (EDN, also known as eosinophil protein X), eosinophil peroxidase (EPO), and major basic protein (MBP) as well as other promising non-eosinophil-derived biomarkers. Although several studies have shown the utility of most biomarkers collected from the serum, esophageal luminal secretions, and feces of EoE patients, numerous limitations currently hamper the integration of such biomarkers in clinical practice. Future studies should aim at validating the utility of non-invasive and minimally invasive biomarkers using rigorous protocols and updated consensus criteria for EoE.

Effect of Proton Pump Inhibitor Treatment in "PPI Non-responsive" Patients with Eosinophilic Esophagitis

BACKGROUND AND AIMS

Some eosinophilic esophagitis (EoE) patients can have a decline in eosinophil count after proton pump inhibitor (PPI) treatment without achieving histologic response, but little is known about this group. We aimed to determine the effect of PPIs on reducing esophageal eosinophilia in patients deemed non-responsive to PPI therapy.

METHODS

We analyzed prospectively collected cohort data from newly diagnosed adults with EoE who were histologic non-responders (≥15 eos/hpf) to PPI-only therapy. Symptoms, endoscopic histologic features were assessed before and after PPI. Pre- and post-PPI treatment esophageal biopsies were read by pathologists to determine peak eosinophil counts and other histologic findings.

RESULTS

Of 125 patients, peak eosinophil counts were 102.1 ± 69.8 and 102.9 ± 101.1 (p=0.93) before and after PPI treatment, respectively, but lamina propria fibrosis decreased from 97% to 41% (p<0.001). Heartburn frequency also decreased (19% to 11%; p=0.006), though endoscopic findings did not change. There were 75 patients (60%) who had some decrease in eosinophil counts, with 30 patients (24%) having ≥50% decrease in counts. When comparing the ≥50% and <50% decrease groups, differences in endoscopic features were identified, but the ≥50% group had improvement in eosinophil degranulation, microabscesses, spongiosis, and basal cell hyperplasia.

CONCLUSION

Peak eosinophil counts did not decrease overall after PPI treatment, but symptoms of heartburn improved. Approximately a quarter had ≥50% decrease in eosinophil counts, with associated decreases in other histologic findings. Further research may consider what role PPIs have in this subset of non-responders or in combination therapies.

Pre-treatment differential correlation of gene expression and response to topical steroids in eosinophilic esophagitis

Few predictors of response to topical corticosteroid (tCS) treatment have been identified in eosinophilic esophagitis (EoE). We aimed to determine whether baseline gene expression predicts histologic response to tCS treatment for EoE. We analyzed prospectively collected samples from incident EoE cases who were treated with tCS for 8 weeks in a development cohort (prospective study) or in an independent validation cohort (clinical trial). Whole transcriptome RNA expression was determined from a baseline (pre-treatment) RNA-later preserved esophageal biopsy. Baseline expression was compared between histologic responders (<15 eos/hpf) and non-responders (≥15 eos/hpf), and differential correlation was used to assess baseline gene expression by response status. In 87 EoE cases analyzed in the development set, there were no differentially expressed genes associated with treatment response (at false discovery rate = 0.1). However, differential correlation identified a module of 22 genes with statistically significantly high pairwise correlation in non-responders (mean correlation coefficient = 0.7) compared to low correlation in responders (coefficient = 0.3). When this 22-gene module was applied to the 89 EoE cases in the independent cohort, it was not validated to predict tCS response at the 15 eos/hpf threshold (mean correlation coefficient = 0.32 in responders and 0.25 in nonresponders). Exploration of other thresholds also did not validate any modules. Though we identified a 22 gene differential correlation module measured pre-treatment that was strongly associated with subsequent histologic response to tCS in EoE, this was not validated in an independent population. Alternative methods to predict steroid response should be explored.

Assessment of local and systemic signature of eosinophilic esophagitis (EoE) in children through multi-omics approaches

Background

Eosinophilic oesophagitis (EoE) is a chronic food allergic disorder limited to oesophageal mucosa whose pathogenesis is still only partially understood. Moreover, its diagnosis and follow-up need repeated endoscopies due to absence of non-invasive validated biomarkers. In the present study, we aimed to deeply describe local immunological and molecular components of EoE in well-phenotyped children, and to identify potential circulating EoE-biomarkers.

Methods

Blood and oesophageal biopsies were collected simultaneously from French children with EoE (n=17) and from control subjects (n=15). Untargeted transcriptomics analysis was performed on mRNA extracted from biopsies using microarrays. In parallel, we performed a comprehensive analysis of immune components on both cellular and soluble extracts obtained from both biopsies and blood, using flow cytometry. Finally, we performed non-targeted plasma metabolomics using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Uni/multivariate supervised and non-supervised statistical analyses were then conducted to identify significant and discriminant components associated with EoE within local and/or systemic transcriptomics, immunologic and metabolomics datasets. As a proof of concept, we conducted multi-omics data integration to identify a plasmatic signature of EoE.

Results

French children with EoE shared the same transcriptomic signature as US patients. Network visualization of differentially expressed (DE) genes highlighted the major dysregulation of innate and adaptive immune processes, but also of pathways involved in epithelial cells and barrier functions, and in perception of chemical stimuli. Immune analysis of biopsies highlighted EoE is associated with dysregulation of both type (T) 1, T2 and T3 innate and adaptive immunity, in a highly inflammatory milieu. Although an immune signature of EoE was found in blood, untargeted metabolomics more efficiently discriminated children with EoE from control subjects, with dysregulation of vitamin B6 and various amino acids metabolisms. Multi-blocks integration suggested that an EoE plasma signature may be identified by combining metabolomics and cytokines datasets.

Conclusions

Our study strengthens the evidence that EoE results from alterations of the oesophageal epithelium associated with altered immune responses far beyond a simplistic T2 dysregulation. As a proof of concept, combining metabolomics and cytokines data may provide a set of potential plasma biomarkers for EoE diagnosis, which needs to be confirmed on a larger and independent cohort.

Blood-Based Biomarkers for Eosinophilic Esophagitis and Concomitant Atopic Diseases: A Look into the Potential of Extracellular Vesicles

Eosinophilic esophagitis (EoE) is a chronic, Th2-inflammatory disease of the esophagus that can severely affect food intake. Currently, diagnosis and assessing response to treatment of EoE is highly invasive and requires endoscopy with esophageal biopsies. Finding non-invasive and accurate biomarkers is important for improving patient well-being. Unfortunately, EoE is usually accompanied by other atopies, which make it difficult to identify specific biomarkers. Providing an update of circulating EoE biomarkers and concomitant atopies is therefore timely. This review summarizes the current knowledge in EoE blood biomarkers and two of its most common comorbidities, bronchial asthma (BA) and atopic dermatitis (AD), focusing on dysregulated proteins, metabolites, and RNAs. It also revises the current knowledge on extracellular vesicles (EVs) as non-invasive biomarkers for BA and AD, and concludes with the potential use of EVs as biomarkers in EoE.

EoE behaves as a unique Th2 disease: a narrative review

Background and Objective

To highlight and interpret two significant differences between eosinophilic esophagitis (EoE), a type 2 helper cell (Th2) disease, and three other representative Th2 diseases. EoE, asthma, atopic dermatitis (AD), chronic rhinosinusitis (CRS) and other Th2 diseases employ epithelial alarmins to recognize triggers, share a prototypical inflammatory cascade, and respond to glucocorticoids. However, EoE also has several distinguishing characteristics which may be explained by a distinct pathophysiologic mechanism.

Methods

The following report consist of four related narrative reviews which combine comprehensive PubMed and Google searches. Two reviews were performed to identify and contrast all eligible studies describing serologic markers in EoE compared to asthma, AD, and CRS. Two additional reviews then compare the responses to parenteral biological therapies in EoE and in the same representative Th2 diseases.

Key Content and Findings

Comprehensive literature searches definitively differentiate the absence of serologic markers in EoE compared to their identification in the other representative Th2 diseases. Similarly, a summary of therapeutic trials demonstrates that while EoE is unable to clinically respond to a variety of parenteral biological therapies, asthma, AD and CRS are very effectively treated with this same approach. A novel pathophysiology for EoE is proposed, and the emerging literature that support its existence is summarized.

Conclusions

The fundamental properties described in this narrative regarding serologic signaling and response to parenteral therapy in EoE could be explained if EoE employs a unique application of the Th2 pathway. One potential mechanism consistent with these observations is that EoE employs exclusively esophageal mucosal constituents to initiate and generate the prototypical Th2 cascade and the fibrostenotic changes that follow.

Plasma Biomarkers and Fractional Exhaled Nitric Oxide in the Diagnosis of Eosinophilic Esophagitis

OBJECTIVES

Eosinophilic esophagitis (EoE) is a chronic disease which requires endoscopy with biopsies for diagnosis and monitoring. We aimed to identify a panel of non-invasive markers that could help identify patients with active EoE.

METHODS

In this prospective cohort study, we enrolled 128 children aged 5-18 years old, scheduled for endoscopy for suspected esophageal or peptic disease. On the day of the endoscopy, fractionated exhaled nitric oxide (FeNO) was measured; and blood was collected for peripheral absolute eosinophil count (AEC), plasma amino acids, and plasma polyamine analysis. Patients were grouped into controls (n = 91), EoE in remission (n = 16), or active EoE (n = 21), based on esophageal eosinophilia and history of EoE.

RESULTS

AEC was not statistically significant different among the groups compared ( P = 0.056). Plasma amino acids: citrulline (CIT), β-alanine (β-ALA), and cysteine (CYS) were higher in active EoE compared to controls ( P < 0.05). The polyamine spermine was lower in active EoE versus controls ( P < 0.05). Receiver operator characteristic (ROC) curve to assess the predictive capability of a combined score made of FeNO, β-ALA, CYS, and spermine had an area under curve (AUC) of 0.90 (95% CI: 0.80-0.96) in differentiating active EoE from controls and 0.87 (95% CI: 0.74-1.00) when differentiating active EoE from EoE in remission.

CONCLUSION

A panel comprising FeNO, 2 plasma amino acids (β-ALA, CYS) and the polyamine spermine can be used as a non-invasive tool to differentiate active EoE patients from controls.

Oesophageal secretions reveal local food-specific antibody responses in eosinophilic oesophagitis

BACKGROUND

Eosinophilic oesophagitis (EoE) is associated with elevated IgG4 in oesophageal tissue and serum. Previously, we showed brush-collected oesophageal secretions of EoE patients contained food antigen-specific antibodies IgA and IgG4. It is unknown whether other food-specific antibodies are present along the surface of the oesophagus in EoE.

AIM

To identify whether immunoglobulins other than IgG4 and food-specific antibodies are elevated along the oesophageal mucosal surface in oesophageal secretions in EoE patients METHODS: Concentrations of total IgA, IgG1, IgG2, IgG3, IgG4, IgM and IgE were measured in oesophageal secretions from patients with active (n = 19) and inactive EoE (n = 9), and non-EoE controls (n = 10). Food-specific antibodies were measured using beads coupled to protein components from dairy, wheat and egg. Total immunoglobulin and cytokine and chemokine concentrations were measured in serum, saliva and oesophageal secretions of four patients with active EoE.

RESULTS

Oesophageal secretions have a unique immune profile. Patients with active EoE had elevated IgG2, IgG4 and IgM concentrations in oesophageal secretions compared to those with inactive EoE. Food-specific IgG1, IgG2, IgG4 and IgM were significantly increased in patients with active EoE compared to inactive EoE and non-EoE patients. Furthermore, active patients with a known dairy trigger display higher dairy-specific IgG1, IgG2, IgG4, IgM, IgA and IgE.

CONCLUSIONS

There is a distinct localised profile of immunoglobulins and food-specific antibodies found within oesophageal secretions in EoE. These findings expand our knowledge about the currently identified immune responses in EoE and suggest possible roles for multiple immunoglobulins and food-specific antibodies in the pathophysiology of EoE.

Endoscopic approach to eosinophilic esophagitis: American Society for Gastrointestinal Endoscopy Consensus Conference

Endoscopy plays a critical role in caring for and evaluating the patient with eosinophilic esophagitis (EoE). Endoscopy is essential for diagnosis, assessment of response to therapy, treatment of esophageal strictures, and ongoing monitoring of patients in histologic remission. To date, less-invasive testing for identifying or grading EoE severity has not been established, whereas diagnostic endoscopy as integral to both remains the criterion standard. Therapeutic endoscopy in patients with adverse events of EoE may also be required. In particular, dilation may be essential to treat and attenuate progression of the disease in select patients to minimize further fibrosis and stricture formation. Using a modified Delphi consensus process, a group of 20 expert clinicians and investigators in EoE were assembled to provide guidance for the use of endoscopy in EoE. Through an iterative process, the group achieved consensus on 20 statements yielding comprehensive advice on tissue-sampling standards, gross assessment of disease activity, use and performance of endoscopic dilation, and monitoring of disease, despite an absence of high-quality evidence. Key areas of controversy were identified when discussions yielded an inability to reach agreement on the merit of a statement. We expect that with ongoing research, higher-quality evidence will be obtained to enable creation of a guideline for these issues. We further anticipate that forthcoming expert-generated and agreed-on statements will provide valuable practice advice on the role and use of endoscopy in patients with EoE.

Models and Tools for Investigating Eosinophilic Esophagitis at the Bench

Eosinophilic esophagitis (EoE) is an increasingly common food allergy disease of the esophagus that received its medical designation code in 2008. Despite this recency, great strides have been made in the understanding of EoE pathophysiology and type 2 immunity through basic and translational scientific investigations conducted at the bench. These advances have been critical to our understanding of disease mechanisms and generating new hypotheses, however, there currently is only one very recently approved FDA-approved therapy for EoE, leaving a great deal to be uncovered for patients with this disease. Here we review some of the innovative methods, models and tools that have contributed to the advances in EoE discovery and suggest future directions of investigation to expand upon this foundation.

Making Research Flourish Through ESPGHAN: A Position Paper From the ESPGHAN Special Interest Group for Basic and Translational Research

ABSTRACT

Recent research breakthroughs have emerged from applied basic research throughout all scientific areas, including adult and paediatric gastroenterology, hepatology and nutrition (PGHAN). The research landscape within the European Society of Paediatric Gastroenterology and Nutrition (ESPGHAN) is also inevitably changing from clinical research to studies involving applied laboratory research. This position paper aims to depict the current status quo of basic science and translational research within ESPGHAN, and to delineate how the society could invest in research in the present and future time. The paper also explores which research areas in the field of PGHAN represent the current and future priorities, and what type of support is needed across the ESPGHAN working groups (WGs) and special interest groups (SIGs) to fulfil their research goals.

Noninvasive biomarkers identify eosinophilic esophagitis: A prospective longitudinal study in children

BACKGROUND

Esophageal histology is critical for diagnosis and surveillance of disease activity in eosinophilic esophagitis (EoE). A validated noninvasive biomarker has not been identified. We aimed to determine the utility of blood and urine eosinophil-associated proteins to diagnose EoE and predict esophageal eosinophilia.

METHODS

Blood and urine were collected from children undergoing endoscopy with biopsy. Absolute eosinophil count (AEC), plasma eosinophil-derived neurotoxin (EDN), eosinophil cationic protein (ECP), major basic protein-1 (MBP-1), galectin-10 (CLC/GAL-10), Eotaxin-2 and Eotaxin-3, and urine osteopontin (OPN) and matrix metalloproteinase-9 (MMP-9) were determined. Differences were assessed between EoE and control, and with treatment response. The capacity to predict EoE diagnosis and esophageal eosinophil counts was assessed.

RESULTS

Of 183 specimens were collected from 56 EoE patients and 15 non-EoE controls with symptoms of esophageal dysfunction; 33 EoE patients had paired pre- and post-treatment specimens. Plasma (CLC/GAL-10, ECP, EDN, Eotaxin-3, MBP-1) and urine (OPN) biomarkers were increased in EoE compared to control. A panel comprising CLC/GAL-10, Eotaxin-3, ECP, EDN, MBP-1, and AEC was superior to AEC alone in distinguishing EoE from control. AEC, CLC/GAL-10, ECP, and MBP-1 were significantly decreased in patients with esophageal eosinophil counts <15/hpf in response to treatment. AEC, CLC/GAL-10, ECP, EDN, OPN, and MBP-1 each predicted esophageal eosinophil counts utilizing mixed models controlled for age, gender, treatment, and atopy; AEC combined with MBP-1 best predicted the counts.

CONCLUSIONS

We identified novel panels of eosinophil-associated proteins that along with AEC are superior to AEC alone in distinguishing EoE from controls and predicting esophageal eosinophil counts.

Noninvasive tests for eosinophilic esophagitis: Ready for use?

OBJECTIVE

To summarize the existing literature for several promising minimally invasive tests to measure disease activity in eosinophilic esophagitis (EoE).

DATA SOURCES

Literature searches were performed using PubMed. Keyword combinations included eosinophilic esophagitis and minimally invasive techniques, including the esophageal string test, Cytosponge, transnasal endoscopy, technetium-labeled heparin, and noninvasive biomarkers.

STUDY SELECTIONS

Retrospective and prospective observational studies, peer-reviewed reviews, and systematic reviews were selected. Data were reviewed and summarized.

RESULTS

Various techniques have been developed in recent years to measure disease activity in EoE without the need for conventional endoscopy. Our review summarizes the data on these techniques, the benefits and limitations, and future directions for implementation in both research and clinical care.

CONCLUSION

Tremendous progress has been made toward developing minimally invasive techniques to measure disease activity in EoE. Each of the techniques mentioned in this review has advantages and disadvantages, and some are closer to widespread use than others.

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

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

A Model Using Clinical and Endoscopic Characteristics Identifies Patients at Risk for Eosinophilic Esophagitis According to Updated Diagnostic Guidelines

BACKGROUND AND AIMS

Updated diagnostic guidelines for eosinophilic esophagitis (EoE) have eliminated the requirement for a proton pump inhibitor (PPI) trial, but there are no models to identify patients with EoE based on these new criteria. We aimed to develop a predictive model for diagnosis of EoE based on the updated EoE diagnostic guidelines.

METHODS

We performed a secondary analysis of a prospective study of adult patients referred for outpatient esophagogastroduodenoscopy at University of North Carolina who had symptoms of esophageal dysfunction; patients with prevalent EoE were excluded. We analyzed data from 206 EoE cases (mean age 40.1, 62.6% male, 93.2% white) and 306 controls (mean age 52.3, 37.9% male, 79.7% white). We built predictive models for case-control status, using clinical, endoscopic, and histologic features, and defining EoE by either the new or historical definition of PPI non-response. Model discrimination was assessed by the area under the receiver-operator characteristic curve (AUC).

RESULTS

Before endoscopy, younger age, male sex, history of atopic condition or food allergy, and dysphagia identified patients with EoE with an AUC of 0.83. When we included endoscopy findings suggestive of EoE, the model identified patients with EoE with an AUC of 0.92; this increased to 0.99 when histology was included.

CONCLUSION

We developed a model to identify patients with EoE, without a trial of PPIs, based on updated diagnostic guidelines. Clinical features and endoscopic findings identified patients with EoE with an AUC of 0.92-even without histologic data and in the absence of dysphagia. This model can be used to select patients with upper gastrointestinal symptoms but without dysphagia for early diagnostic endoscopy. The model can also be used to identify cases of EoE when eosinophil counts are greater than 15 in biopsies but other causes of esophageal eosinophilia cannot necessarily be excluded.

Searching for Noninvasive Predictors of the Diagnosis and Monitoring of Eosinophilic Esophagitis-The Importance of Biomarkers of the Inflammatory Reaction Involving Eosinophils

Background: Invasive and costly endoscopic diagnosis is obligatory for the diagnosis and monitoring of eosinophilic esophagitis (EoE). This study aims to evaluate the usefulness of serum biomarkers involved in eosinophil-mediated inflammation in the management of EoE. Methods: A prospective cohort study was conducted in 58 patients with dysphagia. Each participant completed a health questionnaire, underwent esophagogastroduodenoscopy with esophageal biopsy for histopathological examination and assessment of total, inflammatory and fibrostenotic Eosinophilic Esophagitis Reference Score (EREFS). Serum levels of interleukin 5 (IL-5), interleukin 13 (IL-13), transforming growth factor β1 (TGF-β1), major basic protein (MBP), and eotaxin 3 were determined by enzyme immunoassays. Total of 16 patients meeting the histological criteria for EoE were treated with proton pump inhibitors for 8 weeks, and then the same diagnostics was performed again. Results: Statistically significantly higher concentrations of MBP and TGF-β1 were demonstrated in the group of patients with EoE, while MBP and eotaxin 3 correlated with the peak eosinophil count (PEC). Baseline MBP levels and eotaxin 3 after treatment significantly positively correlated with EREFS. There was a negative correlation between IL-13 and fibrostenotic EREFS. Additionally, after treatment, a negative correlation TGF-β1 was noted with the inflammatory EREFS and a positive correlation with the fibrostenotic EREFS. Conclusions: The potential role of MBP in predicting the diagnosis of EoE, eotaxin 3 in predicting the advancement and correlation of IL-13 and TGF-β1 in differentiating the inflammatory and fibrotic course of the disease may facilitate the management and individualization of EoE therapy.

Impact of food challenge on local oesophageal immunophenotype in eosinophilic oesophagitis

BACKGROUND

Eosinophilic oesophagitis (EoE) is caused by the ingestion of food antigens. Dietary avoidance can result in clinical and histological remission, while food reintroduction can cause recurrence. It is uncertain if food antigen processing and immune activation occurs locally, in the oesophagus. Therefore, we performed a comparative study of the density of cell surface proteins (known to be involved with antigen presentation) on oesophageal tissue prior to, and following food antigen induced disease recurrence. A secondary aim was to consider novel biomarkers.

METHOD

Adult patients with a diagnosis of EoE, who had achieved histological remission with an elimination diet (<15 eosinophils per high power field at oesophageal biopsy), and who underwent food challenge with proven recurrence were included. Immunohistochemistry/immunofluorescence for CD1a, CD3, CD28, CD40, CD69, CD80, CD138, CXCR3 and HLA-DR was performed. Staining intensity of each biomarker (pixels/mm² ) was quantified by semi-automated analysis (Studio-FL software).

RESULTS

Fourteen cases of EoE (pre and post food challenge), 6 GORD and 5 healthy controls were included. HLA-DR, CD3, CD28, CD40 and CD 138 significantly increased with food reintroduction (P = <0.05). CD1a, CD 69, CD 80 and CXCR3 did not measurably change.

CONCLUSION

The presence of cell surface proteins typically associated with antigen presentation (following food antigen induced recurrence) suggests immune activation occurs in the oesophagus, and the relative lack of langerhans cells (CD1a) may indicate this cell type is unimportant. The cell surface protein CD 138 increases with disease recurrence, is not elevated in GORD or healthy controls, and has promise as a biomarker.

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

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

Image Analysis of Eosinophil Peroxidase Immunohistochemistry for Diagnosis of Eosinophilic Esophagitis

BACKGROUND

Diagnosis of eosinophilic esophagitis (EoE) requires manual quantification of tissue eosinophils. Eosinophil peroxidase (EPX) is an eosinophil-specific, cytoplasmic granule protein released during degranulation.

AIMS

The objective of this study was to evaluate image analysis of EPX immunohistochemistry as an automated method for histologic diagnosis of EoE.

METHODS

We performed a secondary analysis of prospectively collected esophageal biopsies obtained from adult subjects with EoE and controls. Tissue sections were stained with hematoxylin and eosin (H&E) and evaluated for peak eosinophils per high power field (eos/hpf). The same slides were de-stained and re-stained to detect EPX for direct comparison. Slides were digitized, and EPX staining area/mm² was quantified using image analysis. Paired samples were compared for changes in EPX staining in treatment responders and non-responders.

RESULTS

Thirty-eight EoE cases and 49 controls were analyzed. Among EoE subjects, matched post-treatment biopsies were available for 21 responders and 10 non-responders. Baseline EPX/mm² was significantly increased in EoE subjects and decreased in treatment responders. EPX quantification correlated strongly with eos/hpf (r = 0.84, p < 0.0001) and identified EoE subjects with high diagnostic accuracy (AUC 0.95, p < 0.0001). The optimal diagnostic EPX-positive pixel/area threshold was 17,379 EPX/mm². Several controls (5/49) with < 15 eos/hpf on H&E staining exceeded this cutoff.

CONCLUSIONS

EPX/mm² correlates strongly with eos/hpf, accurately identifies subjects with EoE, and decreases in treatment responders. Automated quantification of intact eosinophils and their degranulation products may enhance pathologic assessment. Future studies are needed to correlate EPX/mm² with symptoms, endoscopic findings, and esophageal distensibility.

Patient-Reported Outcomes and Blood-Based Parameters Identify Response to Treatment in Eosinophilic Esophagitis

BACKGROUND

Noninvasive methods to assess treatment response in eosinophilic esophagitis are needed.

AIMS

Our aim was to determine whether a blood-based biomarker panel centered on immune parameters could identify histologic response to treatment in eosinophilic esophagitis patients.

METHODS

A pilot study involving adult patients with active eosinophilic esophagitis recruited at two Ear, Nose, Throat clinics in Sweden was designed. The patients (n = 20) donated blood and esophageal biopsies and filled in three questionnaires before and after a 2-month course of topical corticosteroids. Blood samples were analyzed for absolute levels of granulocytes and T cells and the fractions of eosinophils expressing 10 different surface markers by flow cytometry. All data were analyzed by multivariate methods of pattern recognition.

RESULTS

Multivariate modeling revealed that a combination of 13 immune parameters and 10 patient-reported outcome scores were required to create a model capable of separating responders (n = 15) from non-responders (n = 5). Questions regarding symptoms of esophageal dysfunction and capacity to eat certain foods from two of the questionnaires were discriminatory in the multivariate model, as were absolute counts of T cells, eosinophils, and eosinophil expression of activation markers and cell adhesion molecules.

CONCLUSIONS

A combination of blood-based immune parameters and directed questions may prove helpful to monitor response to treatment, perhaps reducing the need for repeat endoscopies in eosinophilic esophagitis patients in the future.

Eosinophils and T cell surface molecule transcript levels in the blood differentiate eosinophilic esophagitis (EoE) from GERD

We recently rereported that blood mRNA levels of T cells and IgE receptors are the novel non-invasive biomarkers for eosinophilic esophagitis (EoE) with the aim to establish the panel of T cells and IgE receptor as the novel non-invasive biomarkers for EoE. In addition to earlier proposed cell surface molecules, we now added T cell receptor CXCR6 and eosinophils expressed cell surface molecules CD101 and CD274 mRNA levels. The mRNA levels of eosinophils cell surface molecule CD101 and CD274 and T cell receptor CXCR6, Vβ11, CD1d and chemokine CXCL16 levels were examined using the blood of normal, EoE and GERD patients. The analysis showed statistically significant induced mRNA levels of CD274, CD101 and reduced CXCR6 will be an additional molecule with respective 95%, 90% and 90% positive predictive value in between EoE and GERD patients. In brief, these additional data will be critical to establish a complete panel of earlier published TCRδ (95%), Jα18 (83%) and FCεRII (100%) non-invasive biomarker to monitor the EoE severity and treatment effect in EoE patients. In conclusion, we now propose both induced and reduced transcript levels of cell surface molecules of the cell surface molecules along with earlier reported molecules that will be useful for monitoring EoE status before and following treatment. Most importantly, the complete predictive non-invasive biomarker panel will also serve to differentiate EoE from GERD.

Epigenetic methylation in Eosinophilic Esophagitis: Molecular ageing and novel biomarkers for treatment response

BACKGROUND

Treatment failure in eosinophilic esophagitis (EoE) is common. We hypothesize that DNA methylation differs between patients by treatment response to topical steroids (oral viscous budesonide), thus offering the potential to inform targeting therapies.

OBJECTIVE

We sought to identify differentially methylated sites and affiliated genes in pre-treatment oesophageal cells between responders and non-responders and test for accelerated epigenetic ageing in oesophageal cells of EoE patients.

METHODS

DNA was extracted from prospectively collected and biobanked oesophageal biopsies from 36 Caucasian treatment naïve EoE patients at diagnosis. Methylation assays were completed using the Infinium HumanMethylation450 BeadChip. Normalized β values for each CpG site were tested (t test) for differential methylation. Further, 353 CpG probes were used to estimate epigenetic age for each patient and a linear regression model tested whether chronologic age and epigenetic age differed. Epigenetic age results were confirmed in an independent cohort of healthy controls.

RESULTS

Eighteen CpG sites were differentially methylated by treatment response (P < .00001). The mean epigenetic age and chronological age were 56.1 ± 11.1 and 36.7 ± 12.3 years, a mean age difference of 19.3 ± 5.2 years (P < .0001); accelerated ageing was not observed in the oesophageal cells of healthy controls.

CONCLUSIONS AND CLINICAL RELEVANCE

EoE patients that respond versus do not respond to treatment have differences in their methylation profile, including enrichment of genes in pathways consistent with cellular injury and repair due to environmental stress and cell adhesion and barrier integrity. EoE also appears to accelerate cellular ageing. Whether treatment can arrest or reverse accelerated epigenetic ageing and the implications for long-term disease progression is important areas for future research.

Proton-pump Inhibitor Response Prediction Using Esophageal microRNAs in Children With Eosinophilic Esophagitis

OBJECTIVES

Eosinophilic esophagitis (EoE) is a chronic esophageal disease characterized by eosinophilic inflammation. Proton-pump inhibitors (PPI) induce disease remission but no predictive factors of PPI-responsiveness have been identified yet. So, a biomarker must be found to differentiate between responders (PPI-R) and nonresponder patients (PPI-NR) to PPI. Aims were to identify any molecular biomarker that could predict PPI responsiveness and to study molecular remission after PPI therapy.

METHODS

This prospective study enrolled 39 controls and 43 pediatric children with EoE from 2 hospitals, and they were treated with esomeprazole for 8 to 12 weeks. After therapy, patients were classified as either PPI-R or PPI-NR. Biopsies were collected and RNA, microRNAs, and proteins were isolated from them, measuring levels by qPCR and Western blot (WB). Also, miRNAs were evaluated in serum.

RESULTS

We found several esophageal miRNAs with different expression values between PPI-R and PPI-NR children, which can be used to discriminate them (area under curve = 0.90). No useful serum miRNAs were, however, identified. Also, these miRNAs were dysregulated in responder patients before and after PPI therapy. Moreover, we corroborated in this child population, that PPI-R displayed a significant decrease in eotaxin-3, IL-5, IL-13, periostin, and major basic protein (P < 0.05) and a significant increase in filaggrin levels after PPI treatment (P < 0.01).

CONCLUSIONS

Esophageal miRNA levels found are able to discriminate between both PPI-R and PPI-NR at baseline, and before and after treatment in PPI-R, so they could be used as biomarkers. Furthermore, we observed clinical and esophageal molecular restoration in PPI-R patients after PPI therapy.

Clinical and anatomopathological features of eosinophilic oesophagitis in children and adults

INTRODUCTION

Eosinophilic oesophagitis (EoE) is a chronic clinical-pathological disorder with an immunological basis characterised by symptoms of oesophageal dysfunction and, histologically, eosinophilic inflammation.

OBJECTIVE

To evaluate the clinical characteristics and differences in children and adults diagnosed with EoE in a tertiary level hospital.

METHOD

Descriptive, retrospective and cross-sectional study. We randomly selected 40 children and 40 adults diagnosed with EoE between 2009 and 2016. The patient characteristics were analysed by means of epidemiological, clinical, diagnostic and therapeutic variables.

RESULTS

The average age at diagnosis was 10 years (children) and 34 years (adults), with a higher frequency in males. The majority were sensitised to aeroallergens (77.5% children vs. 82.5% adults) and foods (75% children vs. 82.5% adults). Statistically significant differences were detected in sensitisation to fruits (p=0.007) and grains (p<0.001). Differences were observed in impaction (22.5% children vs. 82.5% adults), dysphagia (42.5% children vs. 77.5% adults) and abdominal pain (25% children vs. 7.5% adults). Endoscopy showed that children had a higher frequency of exudates (92.5%) and adults, trachealisation (50% vs. 5%) and stenosis (17.5% vs. 2.5%). Statistically significant differences were found in treatment with topical corticosteroids (30% children vs. 77.5% adults), with a variable positive response. 77.5% of the patients received elimination diets.

CONCLUSIONS

Statistically significant differences were observed between the paediatric and adult populations in the food sensitisation profiles, clinical manifestations, endoscopic findings and treatments received. This is a complex pathology that calls for a multidisciplinary team and would require new non-invasive techniques to facilitate its management.

Treatment of eosinophlic esophagitis with swallowed topical corticosteroids

Eosinophilic esophagitis (EoE) is an emerging chronic local immune-mediated disease of the esophagus. Beside proton pump inhibitors and food-restriction-diets swallowed topical corticosteroids (STC) can be offered as a first line therapy according to current guidelines. This review describes the background and practical management of STCs in EoE. So far, mainly asthma inhalers containing either budesonide or fluticasone have been administered to the esophagus by swallowing these medications “off label”. Recently esophagus-targeted formulations of topical steroids have been developed showing clinicopathological response rates up to 85% - an orodispersible tablet of budesonide has been approved as the first “in label” medication for EoE in Europe in June 2018. Whereas it was shown that disease remission induction of EoE by STCs is highly effective, there is still a lack of data regarding long-term and maintenance therapy. However, current studies on STC maintenance therapy add some movement into the game.

Early life factors are associated with risk for eosinophilic esophagitis diagnosed in adulthood

Early life exposures have been associated with pediatric eosinophilic esophagitis (EoE), but it is unknown if a similar association is present in adults. We aimed to assess the association between early life risk factors and development of EoE in adulthood. To do this, we conducted a case-control study which was nested within a prospective cohort study of adults undergoing outpatient endoscopy. Cases of EoE were diagnosed per consensus guidelines; controls did not meet these criteria. Subjects and their mothers were contacted to collect information on four key early life exposures: antibiotics taken during the first year of life, Cesarean delivery, preterm delivery (≤37 weeks' gestation), and neonatal intensive care unit (NICU) admission. We calculated the odds of EoE given in each exposure and assessed agreement between subjects and their mothers. For the 40 cases and 40 controls enrolled, we observed a positive association between each of the early life exposures and development of EoE (antibiotics in infancy, OR = 4.64, 95% CI = 1.63-13.2; Cesarean delivery, OR = 3.08, 95% CI = 0.75-12.6; preterm delivery, OR = 2.92, 95% CI = 0.71-12.0; NICU admission, OR = 4.00, 95% CI = 1.01-15.9). Results were unchanged after adjusting for potential confounders, though only early antibiotic use had CIs that did not cross 1.0. Moderate to strong agreement was observed between 54 subject-mother pairs (antibiotics, K = 0.44, P = 0.02; Cesarean delivery, K = 1.0, P < 0.001; preterm delivery, K = 0.80, P < 0.001; NICU, K = 0.76, P < 0.001). In sum, antibiotics in infancy was significantly associated with increased risk of EoE diagnosed in adulthood, while positive trends were seen with other early life factors such as Cesarean delivery, preterm delivery, and NICU admission. This may indicate persistent effects of early life exposures and merits additional study into conserved pathogenic mechanisms.

Eosinophilic Esophagitis: Update on Diagnosis and Treatment in Pediatric Patients

Eosinophilic esophagitis (EoE) is a chronic immune-mediated inflammatory disorder characterized by symptomatic esophageal dysfunction and an eosinophil-predominant inflammation of the esophagus. EoE arises from interaction between genetic and environmental factors. In pediatric patients, clinical manifestations vary depending on age, from a gastroesophageal reflux disease (GERD)-like condition to severe dysphagic symptoms. Upper endoscopy is considered the gold standard for diagnosis and monitoring of EoE; however, significant efforts are underway to identify noninvasive diagnostic tools and biomarkers to avoid repetitive invasive procedures. Therapeutic first-line options currently available for EoE are elimination diets, proton pump inhibitors (PPIs), and steroids. The aim of treatment is to improve clinical symptoms while obtaining mucosal healing and avoiding long-term complications. Dietary treatment options comprise different empiric diets or an exclusively amino acid formula. Despite the efficacy of diets, compliance is often challenging. PPIs and topical steroids represent the main pharmacological options for EoE, and both can induce and maintain remission. Topical steroids have been reported as more effective, but data on long-term safety remain insufficient for both these and PPIs. Endoscopic dilations are currently reserved for severe untreated fibrostenotic disease unresponsive to medical therapies. Several biologic agents are available but not yet approved for EoE.

Contributions of Eosinophils to Human Health and Disease

The human eosinophil has long been thought to favorably influence innate mucosal immunity but at times has also been incriminated in disease pathophysiology. Research into eosinophil biology has uncovered a number of interesting contributions by eosinophils to health and disease. However, it appears that not all eosinophils from all species are created equal. It remains unclear, for example, exactly how having eosinophils benefits the human host when helminth infections in the developed world have become scarce. This review focuses on our current state of knowledge as it relates to human eosinophils. When information is lacking, we discuss lessons learned from mouse studies that may or may not directly apply to human biology and disease. It is an exciting time to be an "eosinophilosopher" because the use of biologic agents that selectively target eosinophils provides an unprecedented opportunity to define the contribution of this cell to eosinophil-associated human diseases.

Poor Correlation of Oral Swabs with Esophageal Eosinophil Counts

Eosinophilic esophagitis (EoE) is a chronic condition that requires repeated endoscopies/biopsies to track the disease and treatment response. This invasive procedure involves risk to the patient and has significant costs. We studied whether the detection of specific proteins (cytokines and eosinophil degranulation products) from oral swabs could serve as a minimally invasive test for EoE. Swabs of the oral cavity (buccal and oropharyngeal) were obtained prior to endoscopy/biopsies in patients with EoE, possible EoE, and non-EoE patients in addition to obtaining additional esophageal biopsy tissue. ELISAs measuring the levels of cytokines IL-5, IL-8, IL-13, and eosinophil degranulation products including major basic protein (MBP), eosinophil derived neurotoxin (EDN), and eosinophil peroxidase (EPO) were performed on the samples. Comparisons were made to peak esophageal eosinophil counts. Tolerability of the swabs was evaluated. 43 patients, 4-17 years old, participated in the study. Swabs were well tolerated and all showed measurable protein. 26 patients had EoE [14 active (> 15 eosinophils/high power field), 12 non-active], 17 patients did not have EoE. Results obtained from oral swabs showed poor correlation with those from esophageal tissue. Only measurement of eosinophil degranulation products EDN and EPO from esophageal tissues showed strong correlations with eosinophil counts. In this study, the levels of cytokines and eosinophil degranulation products detected from oral swabs did not correlate with esophageal eosinophilia, and their detection would be insufficient to displace endoscopy/biopsies.

Eosinophilic esophagitis: pitfalls and controversies in diagnosis and management

Formerly considered a rare disorder, eosinophilic esophagitis (EoE) has emerged as a leading cause of feeding problems in children and an increasingly recognized cause of dysphagia and food impaction in adults. Our understanding of EoE and its complex interplay with gastro-esophageal reflux disease (GERD) has evolved over the past decade and culminated in the introduction of proton pump inhibitor (PPI) responsive EoE as a distinct entity which has added to this complexity. It is now clear that this entity is on the same spectrum as the original EoE, and that PPIs should be considered as part of treatment protocol and should not be recommended as a diagnostic tool. As such, removing the PPI trial from the diagnostic algorithm has been encouraged recently. Recent guidelines and reviews thoroughly address various aspects in EoE pathogenesis and diagnostic workup as well as management endpoints, treatment options and novel therapies. However, despite the recent extensive study and the advances in our knowledge of this disease, unmet needs and pitfalls in diagnostic workup and management of these patients are still to be clarified and will be under focus in this review.

A Conceptual Approach to Understanding Treatment Response in Eosinophilic Esophagitis

While the diagnosis and initial treatment of eosinophilic esophagitis are becoming more standardized, there are still major gaps in knowledge related to measuring treatment response. One such question centers on how to measure treatment response and what treatment endpoints should be. This impacts not only patient care and engagement in decision-making, but also the field of drug development. In addition, studies so far have use a myriad of treatment endpoints including over a dozen histologic endpoint criteria. This review will discuss the various stakeholders involved in assessment of treatment endpoints of a complex condition, including patients, practitioners and regulatory agencies, and the care settings in which treatment response is assessed, including routine clinical care, clinical trials, and observational studies. Potential parameters or treatment endpoints such as histology, symptoms, patient-reported outcomes, endoscopy, and biomarkers are discussed along with associated challenges and opportunities. A framework on how to define treatment outcomes is discussed and a conceptual approach treatment response is proposed. This takes into account histology, symptoms, and endoscopic findings and harnesses existing, validated tools. It includes definitions of nonresponse, complete normalization, and a graded response category between these 2 extremes, and also permits flexibility and latitude for modifications as newer knowledge emerges. In addition, ways to position the pediatric population in these endeavors are discussed as are future research directions.

Eosinophilic esophagitis: Current concepts in diagnosis and treatment

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

New developments in diagnosis and treatment of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic, allergen-driven, immune mediated disease of the esophagus that progresses to esophageal fibrostenosis if not well treated. The aim of this review is to provide an update on recent clinical advances in the development of diagnostic and therapeutic approaches for EoE. At present, the diagnosis and disease monitoring for EoE rely on repetitive endoscopic evaluations and esophageal tissue acquisition for histopathologic analysis. Recent advancements in EoE diagnosis include transnasal endoscopy, endoscopic functional lumen imaging probe, and the emergence of non-invasive diagnostic tools including cytosponge, esophageal string test, and mucosal impedance probe. Biomarkers for EoE have not yet proven their clinical utility. The current treatment modalities for EoE are topical corticosteroid, proton-pump inhibitors, elimination diet, and dilation. Promising results from clinical trials are emerging for biologic agents that target the interleukin (IL)-13 and the IL-4/IL-13 receptor, specifically, RPC4046 and dupilumab. Especially, dupilumab is promising to become the orphan drug of EoE.

Clinical and Molecular Factors Associated With Histologic Response to Topical Steroid Treatment in Patients With Eosinophilic Esophagitis

BACKGROUND & AIMS

Few factors have been identified that can be used to predict response of patients with eosinophilic esophagitis (EoE) to topical steroid treatment. We aimed to determine whether baseline clinical, endoscopic, histologic, and molecular features of EoE can be used to predict histologic response.

METHODS

We collected data from 97 patients with EoE, from 2009 through 2015, treated with a topical steroid for 8 weeks; 59 patients had a histologic response to treatment. Baseline clinicopathologic features and gene expression patterns were compared between patients with a histologic response to treatment (<15 eos/hpf) and non-responders (≥15 eos/hpf). We performed sensitivity analyses for alternative histologic response definitions. Multivariate logistic regression was performed to identify predictive factors associated with response to therapy, which were assessed with area under the receiver operator characteristic (AUROC) curves.

RESULTS

Baseline dilation was the only independent predictor of non-response (odds ratio [OR], 0.30; 95% CI, 0.10-0.89). When an alternate response (<1 eos/hpf) and non-response (<50% decrease in baseline eos/hpf) definition was used, independent predictors of response status were age (OR, 1.08; 95% CI, 1.02-1.14), food allergies (OR, 12.95; 95% CI, 2.20-76.15), baseline dilation (OR, 0.17; 95% CI, 0.03-0.88), edema or decreased vascularity (OR, 0.20; 95% CI, 0.04-1.03), and hiatal hernia (OR, 0.07; 95% CI, 0.01-0.66). Using these 5 factors, we developed a predictive model that discriminated complete responders from non-responders with an AUROC of 0.88. Baseline gene expression patterns were not associated with treatment response and did not change with different histologic response thresholds.

CONCLUSIONS

In an analysis of 97 patients with EoE, we found dilation to be the only baseline factor associated with non-response to steroid treatment (<15 eos/hpf). However, a model comprising 5 clinical, endoscopic, and histologic factors identified patients with a complete response (<1 eos/hpf). A baseline gene expression panel was not predictive of treatment response at any threshold.

Heartburn and dyspepsia symptom severity improves after treatment and correlates with histology in adults with eosinophilic esophagitis

Non-dysphagia symptoms, such as heartburn and dyspepsia, are poorly characterized in adults with eosinophilic esophagitis (EoE). It is unclear if treatment improves these symptoms. The aim of this paper was to assess (i) heartburn and dyspepsia symptom severity in adult EoE patients using validated symptom measures; (ii) change in symptoms after treatment; and (iii) symptom association with endoscopic and histologic features. In a prospective cohort of adult EoE patients who were not responsive to proton pump inhibitor therapy, non-dysphagia symptoms were assessed with heartburn items from the validated GERD-HRQL (gastroesophageal reflux disease health-related quality of life) and SODA (severity of dyspepsia assessment) instruments. Subjects completed the questionnaires at baseline and after treatment. Association of baseline symptoms with endoscopic and histologic features, and before and after treatment with diet or topical steroids, was assessed. Eighty-six EoE patients (mean age 39 years, 57% male, 95% white) completed a baseline questionnaire and 62 completed the follow-up questionnaire. The mean baseline GERD-HRQL score was 4.5 ± 6.5 and the mean total SODA score was 41.0 ± 12.6. At baseline, there was a weak but significant correlation between peak eosinophils and the SODA score (r = 0.28; p = 0.03) and no association between heartburn and SODA scores and endoscopic or other histologic findings. After treatment, there was a decrease in GERD-HRQL heartburn (4.3 vs. 2.6; p = 0.04) and SODA (49.5 vs. 35.5; p = 0.04) scores in histologic responders, but not in nonresponders. In a prospective cohort of EoE patients, baseline eosinophils positively correlated with dyspepsia severity. Heartburn and dyspepsia symptoms improved after treatment in histologic responders.

Serum eosinophilic cationic protein is correlated with food impaction and endoscopic severity in eosinophilic esophagitis

BACKGROUND/AIMS

The aim of the present study was to analyze the diagnostic accuracy of serum eosinophilic cationic protein (ECP) for eosinophilic esophagitis (EoE) and the correlation of ECP with clinical, histopathological, laboratory, and endoscopic features of EoE.

MATERIALS AND METHODS

Fifteen patients with EoE and 14 healthy controls were included in the study. Demographic parameters were recorded. EoE Endoscopic Reference Score (EREFS) was calculated according to endoscopic features, and esophageal biopsies were obtained by a single experienced endoscopist in a patient group. Serum ECP levels (μg/mL), absolute eosinophil count (U/mm3), and maximum peak of eosinophils/high-power field in esophageal biopsies were analyzed.

RESULTS

The median age of all participants was 33.0 (min-max: 18-46) years. There were 27 (93.1%) male patients. Serum ECP level was significantly higher in patients with EoE than in healthy volunteers (20.4 vs. 8.8, p<0.0001). According to the receiver operating characteristic (ROC) curve analysis, ECP had 80% sensitivity and 92.8% specificity to diagnose EoE with a cut-off value of 13.9 µg/mL (area under the ROC curve 0.895; p<0.0001; 95% CI: 0.725-0.978). EREFS (p<0.0001) and the presence of food impaction (p=0.04) were significantly correlated with ECP.

CONCLUSION

Serum ECP is an accurate non-invasive biomarker for EoE with high specificity and sensitivity. In addition, ECP is strongly correlated with EREFS and the symptom of food impaction.

New Developments in the Diagnosis and Treatment of Eosinophilic Esophagitis

PURPOSE OF REVIEW

Eosinophilic esophagitis (EoE) is a chronic, allergen-driven, immune-mediated disease of the esophagus that progresses to esophageal fibrostenosis if left untreated. The aim of this review is to provide a concise update on recent clinically relevant advances in the development of diagnostic and therapeutic approaches for EoE.

RECENT FINDINGS

Current diagnostic and disease monitoring protocols for EoE rely on repetitive endoscopic evaluations and esophageal tissue acquisition for histopathologic analysis. Recent advancements in EoE diagnosis include endoscopic functional lumen imaging probe (FLIP), transnasal endoscopy (TNE), and the emergence of non-invasive diagnostic tools including cytosponge, esophageal string test, and mucosal impedance probe. Biomarkers for EoE have not yet proven their clinical utility. No Food and Drug Administration (FDA)-approved drugs currently exist for the treatment of EoE. Topical corticosteroid, proton-pump inhibitors (PPI), elimination diet, and dilation are the current treatment modalities for confirmed EoE. Promising results from clinical trials are emerging for biologic agents that target the interleukin (IL)-13 and the IL-4/IL-13 receptor, specifically, RPC4046 and dupilumab, respectively. New diagnostic algorithms, non-invasive diagnostic strategies, and treatment modalities for EoE are emerging. Patients with EoE continue to require a multimodal and multi-disciplinary management approach.

Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic disorder characterized by symptoms of esophageal dysfunction and esophageal inflammation with intraepithelial eosinophils. EoE represents an important cause of upper gastrointestinal morbidity. Primary care providers are pivotal for timely and accurate recognition of symptoms of eosinophilic esophagitis, for facilitating diagnoses through specialist referrals, and for understanding management strategies. This process begins with a thorough understanding of the clinical features of EoE, its associated atopic conditions, and its evolving epidemiology.

Trend, clinical presentations and diagnosis of eosinophilic esophagitis in Saudi children

Objectives:

To observe the frequency of eosinophilic esophagitis (EoE), pattern of clinical presentation and diagnosis among Saudi children at 2 tertiary care hospitals in Riyadh, Saudi Arabia.

Methods:

The database of children admitted or seen, and aged less than 18 years over 5 years period and diagnosed with EoE was collected and reviewed. Patients with esophagitis other than EoE were excluded. Patients who had eosinophils count more than 15/high power field (HPF) on esophageal biopsies were given the diagnosis of EoE. Demographic database, clinical parameters, and diagnostic modalities were analyzed by using the Statistical Package for Social Sciences version 22.

Results:

A total of 37 children with the diagnosis of EoE were gathered from 398 upper gastrointestinal endoscopic procedures with the frequency of 9.3%. There were 22 (59.4%) males with a mean±SD age of 9.6±2.3 years and all were Saudi nationals. Dysphagia was the leading presentation in 21 (56.7%) children followed by vomiting in 18 (48.6%), impaction of food bolus in 8 (21.6%) and foreign body in 3 (8.1%). Allergic symptoms were present in 13 (35.1%) children in the form of asthma, 11 (29.7%) multiple food allergies and 5 (13.5%) eczema. Peripheral eosinophil count and immunoglobulin E were raised more than normal in 6 and 5 children respectively. The pH measurements were carried out in 16 (43.2%) and ruled out the reflux. Contrast studies with barium (n=6; 16.2%) and endoscopic findings were significant (n=27; 72.9%).

Conclusion:

Eosinophilic esophagitis is an emerging disease and have a rising trend in Saudi children. Dysphagia, vomiting, and food impaction are the more common presenting features in older children and recurrent vomiting in younger children in addition to associated allergic conditions.

Blind esophageal brushing offers a safe and accurate method to monitor inflammation in children and young adults with eosinophilic esophagitis

Patients with eosinophilic esophagitis (EoE) require frequent evaluation of mucosal inflammation via endoscopy. Instead of endoscopy, mucosal evaluation in adults with esophageal cancer and candidiasis is achieved using a cytology brush inserted through a nasogastric tube (NGT). We conducted a prospective cross-sectional study in children and young adults scheduled for routine esophagogastroduodenoscopy (EGD) where in Phase 1, we performed esophageal brushing through the endoscope under direct visualization and in Phase 2, we inserted the brush through a Cortrak® NGT prior to endoscopy. Eosinophil-derived neurotoxin (EDN) measured by ELISA in the samples extracted from brushes was validated as the sensitive biomarker. We collected 209 esophageal brushing samples from 94 patients and we found that EDN in brushing samples collected via EGD or NGT was significantly higher in patients having active EoE (n = 81, mean EDN 381 mcg/mL) compared with patients having gastroesophageal reflux disease (n = 31, mean EDN 1.9 mcg/mL, P = 0.003), EoE in remission (n = 47, mean EDN 3.7 mcg/mL, P = 0.003), or no disease (n = 50, mean EDN 1.1 mcg/mL, P = 0.003). EDN at a concentration of ≥10 mcg/mL of brushing sample was found to accurately detect active EoE. NGT brushing did not cause any significant adverse effects. We concluded that blind esophageal brushing using an NGT is a fast, less invasive, safe, and well-tolerated technique compared with EGD to detect and monitor EoE inflammation using EDN as the sensitive biomarker.

Pathophysiology of eosinophilic esophagitis: recent advances and their clinical implications

Introduction: Diagnostic and therapeutic strategies in eosinophilic esophagitis (EoE) are evolving. New knowledge regarding the pathophysiology of EoE has been the foundation for updated diagnostic recommendations and new therapeutic trials. Areas covered: We performed structured literature searches in Medline and PubMed, Cochrane meta-analyses, and abstracts of international congresses to review therapeutic approaches for EoE in July 2018. Additional articles were obtained by perusing the references of articles identified in the original PubMed search. Articles were excluded if they did not focus on the mechanism of disease, diagnosis, or treatment of humans with EoE. Expert commentary: Recent advances in the understanding of mechanisms underlying the pathology of EoE have resulted in significant change in the diagnostic algorithm for EoE, and are identifying promising potential targets for personalized medicine. There is a clinical need for improved targeted therapy for EoE, and better understanding the underlying pathophysiology of EoE will help to determine therapeutic targets. In this review, we highlight key mechanisms in the pathophysiology of EoE and how they are being utilized to change therapy in 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.