Minimally invasive biomarker studies in eosinophilic esophagitis: A systematic review

Future of therapy and monitoring for eosinophilic esophagitis and eosinophilic gastrointestinal diseases

Eosinophilic gastrointestinal disorders, including eosinophilic esophagitis, are chronic Th2 mediated diseases. Establishing a diagnosis and initiating treatment is crucial to limit disease progression that may lead to tissue remodeling and the development of strictures that significantly impact patient quality of life. Expert consensus guidelines provide a framework for treating eosinophilic esophagitis with diet elimination, proton pump inhibitors, swallowed topical steroids, or dupilumab and for monitoring with sedated endoscopy for gross and histologic evaluation. While this provides an established algorithm for treating and monitoring eosinophilic esophagitis, there is less established for the rarer eosinophilic gastrointestinal disorders (eosinophilic gastritis, enteritis, and colitis). Research advancements continue to emerge at a rapid pace, identifying potential biomarkers, therapeutic targets, and monitoring strategies. In this article, we review the current accepted methods for treating and monitoring eosinophilic gastrointestinal disorders with a focus on eosinophilic esophagitis, assess what is currently under investigation, and provide an aspirational vision for future disease management with a streamlined algorithm of personalized medicine and less invasive monitoring.

Eosinophilic oesophagitis in adults: from symptoms to therapeutic options

Eosinophilic oesophagitis (EoE) is a chronic and progressive immune-mediated condition, typically affecting young atopic male adults and potentially leads to organ dysfunction and fibrosis. The clinical spectrum widely varies -from non-troublesome dysphagia to food impaction- and hence the rate of misdiagnosis and diagnostic delay are high, especially when presenting with minor symptoms, such as heartburn and acid regurgitation. There have been several major therapeutic breakthroughs for the management of EoE in recent years. Highly effective conventional agents with oesophagus-specific formulations (i.e. orodispersible budesonide) and a biological agent (i.e. dupilumab) now have a formal indication. Oesophageal dilation may be indicated in case of strictures, which are more common in longstanding and untreated disease. Therefore, the early diagnosis of this disorder and specialist referral is if of great importance. The evaluation of alarm signs and typical presentation patterns should allow a more straightforward recognition. The emergency and internal medicine doctors should actively be involved in this process and take part to the multidisciplinary care of patients with EoE, to allow better patient care and clinical outcomes.

Proton pump inhibitor effect on esophageal protein signature of eosinophilic esophagitis, prediction, and evaluation of treatment response

BACKGROUND

Recently, we have identified a dysregulated protein signature in the esophageal epithelium of eosinophilic esophagitis (EoE) patients including proteins associated with inflammation and epithelial barrier function; however, the effect of proton pump inhibitor (PPI) treatment on this signature is unknown. Herein, we used a proteomic approach to investigate: (1) whether PPI treatment alters the esophageal epithelium protein profile observed in EoE patients and (2) whether the protein signature at baseline predicts PPI response.

METHODS

We evaluated the protein signature of esophageal biopsies using a cohort of adult EoE (n = 25) patients and healthy controls (C) (n = 10). In EoE patients, esophageal biopsies were taken before (pre) and after (post) an 8-week PPI treatment, determining the histologic response. Eosinophil count PostPPI was used to classify the patients: ≥15 eosinophils/hpf as non-responders (non-responder) and < 15 eosinophils/hpf as responders (R). Protein signature was determined and differentially accumulated proteins were characterized to identify altered biological processes and signaling pathways.

RESULTS

Comparative analysis of differentially accumulated proteins between groups revealed common signatures between three groups of patients with inflammation (responder-PrePPI, non-responder-PrePPI, and non-responder-PostPPI) and without inflammation (controls and responder-PostPPI). PPI therapy almost reversed the EoE specific esophageal protein signature, which is enriched in pathways associated with inflammation and epithelial barrier function, in responder-PostPPI. Furthermore, we identified a set of candidate proteins to differentiate responder-PrePPI and non-responder-PrePPI EoE patients before treatment.

CONCLUSION

These findings provide evidence that PPI therapy reverses the alterations in esophageal inflammatory and epithelial proteins characterizing EoE, thereby providing new insights into the mechanism of PPI clinical response. Interestingly, our results also suggest that PPI response could be predicted at baseline in EoE.

Biomarkers for a less invasive strategy to predict children with eosinophilic esophagitis

BACKGROUND

Noninvasive biomarkers for diagnosing and monitoring eosinophilic esophagitis (EoE) are currently lacking. This study evaluates 20 biomarkers in serum and saliva, aiming to assess their diagnostic potential in pediatric EoE patients and healthy individuals.

METHODS

Blood and saliva from children undergoing upper endoscopy were analyzed for biomarkers, including absolute eosinophil count (AEC), eosinophil-derived neurotoxin (EDN), total and specific IgG4-antibodies (sIgG4), specific IgE-antibodies (sIgE) and 15-hydroxyeicosatetraenoic acid (15(S)-HETE). Some patients participated twice, forming a longitudinal cohort. The ability to use the biomarkers to predict the EoE diagnosis was evaluated.

RESULTS

Analysis from 105 children divided into active EoE, remission, and healthy, revealed elevated levels of serum biomarkers (AEC, EDN, 15(S)-HETE, sIgG4, and sIgE) in active EoE compared to healthy individuals. A combination of biomarkers (AEC, EDN, sIgE to egg white and wheat) and symptoms showed an AUC of 0.92 in distinguishing between the three groups. We further showed that optimal cutoff values for these biomarkers could discriminate between active EoE and healthy with a sensitivity of 88% and a specificity of 100% in distinguishing EoE (active and in remission) from healthy. Longitudinally, levels of EDN, sIgG4 to Bos d 4, Bos d 5, Bos d 8, gliadin, and birch, and sIgE to milk decreased in patients progressing from active EoE to remission (p <.05).

CONCLUSIONS

This study identified novel biomarkers associated with EoE and proposes a panel, together with symptoms, for effective discrimination between active EoE, EoE in remission, and healthy individuals. The findings may contribute to a less invasive diagnostic method and may be a potential surveillance tool for pediatric EoE patients.

Concurrent Celiac Disease and Eosinophilic Esophagitis in a Pediatric Cohort: More Than a Coincidence

Celiac disease (CeD) and eosinophilic esophagitis (EoE) are immune-mediated disorders that can occur in the same patient. A retrospective study at a tertiary care hospital was conducted to determine the prevalence of EoE in a pediatric population with CeD and to compare characteristics of patients with both diseases to patients with CeD-only. Among the 148 patients with CeD identified in the study, 11 patients had both CeD and EoE (7.4%). Patients with both CeD and EoE had a higher absolute eosinophil count (per μL) at diagnosis compared to patients with CeD-only (454.1 ± 122.7 vs 231.9 ± 19.4, P = .003). In conclusion, there was a higher proportion of EoE in patients with CeD than would be expected in the general population, suggesting a potential pathophysiological overlap between the 2 diseases. An elevated peripheral absolute eosinophil count may help predict which patients with CeD may additionally have EoE.

Noninvasive Disease Assessment in Eosinophilic Esophagitis With Fractionated Exhaled Nitric Oxide, Blood, and Fecal Biomarkers

BACKGROUND

Eosinophilic Esophagitis (EoE) is a chronic inflammatory condition of the esophagus triggered by food and aeroallergens. There is a need for noninvasive biomarkers that reliably detect EoE in patients with cardinal symptoms and predict treatment response to reduce endoscopic evaluations.

STUDY

Nonasthmatic patients 18 years or above with suspected or diagnosed EoE, gastroesophageal reflux disease (GERD), and control individuals with indication for endoscopy were enrolled prospectively between November 2020 and May 2022. Participants underwent body plethysmography with fractionated exhaled nitric oxide (FeNO) level measurement. Besides, serum and fecal biomarkers were measured by ELISA. A follow-up examination was scheduled after treatment initiation in patients with active EoE.

RESULTS

The median FeNO level in active EoE (20 ppb) was higher compared with GERD (15 ppb, P=0.038) and control individuals (14 ppb, P=0.046). Median FeNO did not significantly differ in EoE patients who underwent follow-up assessment after treatment response (20 ppb vs. 18 ppb, P=0.771). Serum EDN, ECP, and the absolute eosinophil blood count (AEC) were elevated in active EoE compared with control individuals but not compared with GERD except for AEC. Serum EDN, ECP and AEC decreased in EoE in remission at follow-up assessment. None of the fecal biomarkers was elevated in active EoE or during treatment.

CONCLUSIONS

Assessment of FeNO may have diagnostic value in differentiating patients with active EoE from non-EoE patients but is not a suitable marker for monitoring disease activity. Serum EDN, ECP, TARC, and AEC levels are emerging as potential candidates for monitoring disease activity in EoE.

Eosinophilic esophagitis and risk of incident major adverse cardiovascular events: a nationwide matched cohort study

BACKGROUND

Inflammatory diseases have been associated with an increased cardiovascular risk. However, data on incident major adverse cardiovascular events (MACE) from large population-based cohorts of patients with eosinophilic esophagitis (EoE) is lacking.

METHODS

This study included all Swedish adults with EoE without a record of previous cardiovascular disease (CVD) (1990-2017, N = 1546) with follow-up until 2019. Individuals with EoE were identified from prospectively recorded histopathology reports from all Swedish pathology departments (n = 28). EoE patients were matched at index date for age, sex, calendar year and county with up to five general population reference individuals (N = 7281) without EoE or CVD. Multivariable-adjusted hazard ratios (aHRs) for MACE (ischemic heart disease, congestive heart failure, stroke and cardiovascular mortality) were calculated using Cox proportional hazards models. Full sibling comparisons and adjustment for cardiovascular medication were performed.

RESULTS

During a median follow-up of 6.0 years, we observed 65 incident MACE in patients with EoE (6.4/1000 person-years (PY)) and 225 in reference individuals (4.7/1000 PY). EoE was not associated with a higher risk of MACE (aHR = 1.14, 95% CI = 0.86-1.51) or any of its components. No differences between age, sex and follow-up time were observed. The results remained stable in sensitivity analyses, including when adjusting for relevant cardiovascular medications and a full sibling comparison.

CONCLUSIONS

In this large population-based cohort study, patients with EoE had no increased risk of MACE compared to reference individuals and full siblings. The results are reassuring for patients with EoE.

Eosinophilic esophagitis: Current concepts in diagnosis and management

ABSTRACT

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

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.

Minimally Invasive Approaches to Diagnose and Monitor Eosinophilic GI Diseases

PURPOSE OF REVIEW

This review seeks to understand novel avenues for eosinophilic GI disease management. Biomarkers offer a unique and non-invasive approach to tracking EoE disease progression. While no biomarkers have definitively met the diagnostic criteria for eosinophilic GI diseases, some biomarkers have been shown to be associated with disease activity. Here, we examine the potential of recently studied biomarkers.

RECENT FINDINGS

Current research shows advancements in blood, luminal fluid, and breath testing. Particular areas of interest include mRNA analyses, protein fingerprinting, amplicon sequence variants (ASVs), T cells and IgE receptors, eosinophilic cationic proteins, cytokines, and nitric oxide exhalation. Preliminary results showed that mucosal biomarkers, directly captured from the esophagus, may reflect the best representation of biopsy-based results, in contrast to biomarkers obtained from indirect or peripheral (blood, breath) methods. However, this is based on limited clinical studies without sufficient numbers to evaluate true diagnostic accuracy. Large-scale randomized trials are needed to fully ascertain both the optimal sampling technique and the specific biomarkers that reflect diagnostic status of the disease.

Eosinophilic esophagitis: absolute eosinophilic count, peak eosinophilic count, and potential biomarkers of eosinophilic degranulation products-an in-depth systematic review

BACKGROUND

Eosinophilic esophagitis is a chronic inflammatory disorder, often relapsing. There is an increasing need to develop new alternative diagnostic and monitoring methods on a critical basis, which will provide samples through none or minimally invasive procedures. This study aims to identify and document the types and roles of potential biomarkers in eosinophilic esophagitis released by eosinophils as well as the potential relationship to the peak eosinophilic count and the degree of degranulation of in situ eosinophils (DGE/DGE + NDGE: degranulated eosinophils/degranulated eosinophils and non-degranulated eosinophils).

METHODS

This is the first in-depth systematic review study using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) parameters involving a literature search of academic databases (PubMed, Scopus, Medline, Google Scholar, and Cochrane Database, 2011-2022) targeting specifically the eosinophilic counts and ratio, and the eosinophilic degranulation products as potential biomarkers. Data were extracted from ten selected studies and presented on a spreadsheet.

RESULTS

The studies show the ability to detect eosinophilic and non-eosinophilic degranulation products, and absolute eosinophilic count in samples, including blood and urine, thereby serving as potential surrogates in making the diagnosis or monitoring disease progression in the future. There is an obvious paucity of studies that correlate potential biomarkers to the degree of degranulation of in situ eosinophils.

CONCLUSIONS

A few minimally invasive methods and biomarkers may be suggested as alternative tools in diagnosing and monitoring eosinophilic esophagitis. While there is no consensus on the clinical usefulness of these biomarkers, our critical evaluation may suggest that the eosinophilic degranulation ratio (DGE/DGE + NDGE: degranulated eosinophils/degranulated eosinophils and non-degranulated eosinophils) in the esophagus may be critical for evaluating properly these biomarkers. An increasing trend may culminate in the potential clinical use of these biomarkers evaluated not only with the peak eosinophilic count, but also with the degranulation score upon regulatory bodies' approval to monitor eosinophilic esophagitis in the future. We strongly advocate for the necessity to score the esophageal biopsies with both a peak eosinophilic count and a score of the degranulated eosinophils.

Expert Recommendations on the Diagnosis of Eosinophilic Esophagitis in the United Arab Emirates

Eosinophilic esophagitis (EoE) is a chronic, progressive, type 2 inflammatory esophageal disease presenting as dysphagia to solid food and non-obstructive food impaction. Knowledge gaps exist in its diagnosis and management. These expert recommendations focused on the diagnosis of EoE in the United Arab Emirates. An electronic search of PubMed and Embase databases was used to gather evidence from systematic reviews, randomized controlled trials, consensus papers, and expert opinions from the last five years on the diagnosis of EoE. The evidence was graded using the Oxford system. Literature search findings were shared with the expert panel. A 5-point scale (strongly agree, agree, neither agree nor disagree, disagree, and strongly disagree) was used, and a concordance rate of >75% among experts indicated agreement. Using a modified Delphi technique, 18 qualified experts provided 17 recommendations. Eleven statements achieved high agreement, four got moderate agreement, and two got low agreement. Challenges exist in diagnosing EoE, particularly in children. Esophageal biopsies were crucial in diagnosis, irrespective of visible mucosal changes. Further research on diagnostic tools like endoscopic mucosal impedance and biomarkers is needed. Diagnosis relies on esophageal biopsies and symptom-histology correlation; however, tools like EoE assessment questionnaires and endoscopic mucosal impedance could enhance the accuracy and efficiency of EoE diagnosis. The diagnosis of EoE is challenging since the symptoms seldom correlate with the histological findings. Currently, diagnosis is based on patient symptoms and endoscopic and histological findings. Further research into mucosal impedance tests and the role of biomarkers is needed to facilitate diagnosis.

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.

Review article: Emerging insights into the epidemiology, pathophysiology, diagnostic and therapeutic aspects of eosinophilic oesophagitis and other eosinophilic gastrointestinal diseases

BACKGROUND

Eosinophilic gastrointestinal diseases (EGIDs) are chronic, immune-mediated disorders characterised clinically by gastrointestinal symptoms and histologically by a pathologic increase in eosinophil-predominant inflammation in the gastrointestinal tract, in the absence of secondary causes of eosinophilia.

AIMS

To highlight emerging insights and research efforts into the epidemiology, pathophysiology, diagnostic and therapeutic aspects of eosinophilic oesophagitis (EoE) and non-EoE EGIDs, and discuss key remaining knowledge gaps.

METHODS

We selected and reviewed original research, retrospective studies, case series, randomised controlled trials, and meta-analyses.

RESULTS

Standardised nomenclature classifies EGIDs as EoE, eosinophilic gastritis (EoG), eosinophilic enteritis (EoN), and eosinophilic colitis (EoC). Incidence and prevalence of EoE are rising, emphasising the need to better understand how environmental risk factors and genetic features interact. Advances in understanding EoE pathophysiology have led to clinical trials of targeted therapy and the approval (in the United States) of dupilumab for EoE. Several therapies that are under investigation hope to satisfy both histologic and clinical targets. For non-EoE EGIDs, efforts are focused on better defining clinical and histopathologic disease determinants and natural history, as well as establishing new therapies.

CONCLUSIONS

Unmet needs for research are dramatically different for EoE and non-EoE EGIDs. In EoE, non-invasive diagnostic tests, clinicopathologic models that determine the risk of disease progression and therapeutic failure, and novel biologic therapies are emerging. In contrast, in non-EoE EGIDs, epidemiologic trends, diagnostic histopathologic thresholds, and natural history models are still developing for these more rare disorders.

Ethical Implications of Continuing Oral Immunotherapy After the Development of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic allergic inflammatory disease requiring maintenance therapy. Traditionally, EoE has been a contraindication to oral immunotherapy (OIT) and a rationale for discontinuing treatment because OIT may induce EoE. Most, but not all patients with OIT-induced EoE experience symptom resolution and histologic remission after discontinuing OIT. Recent studies report OIT continuation even after EoE onset, despite the previously accepted standard of care. This creates clinical as well as ethical challenges for allergists treating these patients. Considering the published literature on EoE and OIT and the primary medical ethics principles of beneficence, nonmaleficence, autonomy, and justice, we discuss the ethical implications of pursuing desensitization despite the potential complications associated with EoE. When ethical principles are in opposition, shared decision-making should be employed to determine whether OIT should be continued after an EoE diagnosis. This article highlights the ethical dilemmas allergists face when determining whether patients with a diagnosis of EoE should continue OIT.

Proteomic analysis of the esophageal epithelium reveals key features of eosinophilic esophagitis pathophysiology

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic non-IgE-mediated allergic disease of the esophagus. An unbiased proteomics approach was performed to investigate pathophysiological changes in esophageal epithelium. Additionally, an RNAseq-based transcriptomic analysis in paired samples was also carried out.

METHODS

Total proteins were purified from esophageal endoscopic biopsies in a cohort of adult EoE patients (n = 25) and healthy esophagus controls (n = 10). Differentially accumulated (DA) proteins in EoE patients compared to control tissues were characterized to identify altered biological processes and signaling pathways. Results were also compared with a quantitative proteome dataset of the human esophageal mucosa. Next, results were contrasted with those obtained after RNAseq analysis in paired samples. Finally, we matched up protein expression with two EoE-specific mRNA panels (EDP and Eso-EoE panel).

RESULTS

A total of 1667 proteins were identified, of which 363 were DA in EoE. RNA sequencing in paired samples identified 1993 differentially expressed (DE) genes. Total RNA and protein levels positively correlated, especially in DE mRNA-proteins pairs. Pathway analysis of these proteins in EoE showed alterations in immune and inflammatory responses for the upregulated proteins, and in epithelial differentiation, cornification and keratinization in those downregulated. Interestingly, a set of DA proteins, including eosinophil-related and secreted proteins, were not detected at the mRNA level. Protein expression positively correlated with EDP and Eso-EoE, and corresponded with the most abundant proteins of the human esophageal proteome.

CONCLUSIONS

We unraveled for the first time key proteomic features involved in EoE pathogenesis. An integrative analysis of transcriptomic and proteomic datasets provides a deeper insight than transcriptomic alone into understanding complex disease mechanisms.

Monitoring Patients With Eosinophilic Esophagitis in Routine Clinical Practice - International Expert Recommendations

BACKGROUND & AIMS

There are no studies or recommendations on optimal monitoring strategies for patients with eosinophilic esophagitis (EoE). Our objective was to develop guidance on how to monitor patients with EoE in routine clinical practice, on the basis of available clinical evidence and expert opinion.

METHODS

A multidisciplinary, international group of EoE experts identified the following important 3 questions during several consensus meetings: why, by what means, and when to monitor patients with EoE. A steering committee was named, and 3 teams were formed to review literature and to formulate statements for each topic. In a Delphi survey, a level of agreement of ≥75% was defined as threshold value for acceptance. In a final conference, results were presented, critical points and comments on the statements were discussed, and statements were rephrased/rewritten if necessary.

RESULTS

Eighteen EoE experts (14 adult and pediatric gastroenterologists, 2 pathologists and 2 allergists) with a median of 21.7 years in clinical practice, mostly academic or university-based, completed the Delphi survey, which included 11 statements and a proposed algorithm for monitoring patients with EoE. Each statement attained ≥75% agreement. Participants discussed and debated mostly about the statement concerning surveillance intervals for EoE patients with stable disease.

CONCLUSIONS

It was concluded that effective maintenance treatment probably reduces the development of EoE complications, and regular, structured, and, under certain conditions, individualized clinical follow-up is recommended to assess disease activity while opening a window to monitoring side effects, adjusting therapy, and encouraging adherence to treatment. Follow-up should comprise symptom assessment and periodic or repeated endoscopy with histological assessment in specific EoE settings.

Diagnostic role of fractional exhaled nitric oxide in pediatric eosinophilic esophagitis, relationship with gastric and duodenal eosinophils

BACKGROUND

Eosinophilic esophagitis (EoE) is an eosinophilic-predominant inflammation of the esophagus diagnosed by upper endoscopy and biopsies. A non-invasive and cost-effective alternative for management of EoE is being researched. Previous studies assessing utility of fractional exhaled nitric oxide (FeNO) in EoE were low powered. None investigated the contribution of eosinophilic inflammation of the stomach and duodenum to FeNO.

AIM

To assess the utility of FeNO as a non-invasive biomarker of esophageal eosinophilic inflammation for monitoring disease activity.

METHODS

Patients aged 6-21 years undergoing scheduled upper endoscopy with biopsy for suspected EoE were recruited in our observational study. Patients on steroids and with persistent asthma requiring daily controller medication were excluded. FeNO measurements were obtained in duplicate using a chemiluminescence nitric oxide analyzer (NIOX MINO, Aerocrine, Inc.; Stockholm, Sweden) prior to endoscopy. Based on the esophageal peak eosinophil count (PEC)/high power field on biopsy, patients were classified as EoE (PEC ≥ 15) or control (PEC ≤ 14). Mean FeNO levels were correlated with presence or absence of EoE, eosinophil counts on esophageal biopsy, and abnormal downstream eosinophilia in the stomach (PEC ≥ 10) and duodenum (PEC ≥ 20). Wilcoxon rank-sum test, Spearman correlation, and logistic regression were used for analysis. P value < 0.05 was considered significant.

RESULTS

We recruited a total of 134 patients, of which 45 were diagnosed with EoE by histopathology. The median interquartile range FeNO level was 17 parts per billion (11-37, range: 7-81) in the EoE group and 12 parts per billion (8-19, range: 5-71) in the control group. After adjusting for atopic diseases, EoE patients had significantly higher FeNO levels as compared to patients without EoE (Z = 3.33, P < 0.001). A weak yet statistically significant positive association was found between the number of esophageal eosinophils and FeNO levels (r = 0.30, P < 0.005). On subgroup analysis within the EoE cohort, higher FeNO levels were noted in patients with abnormal gastric (n = 23, 18 vs 15) and duodenal eosinophilia (n = 28, 21 vs 14); however, the difference was not statistically significant.

CONCLUSION

After ruling out atopy as possible confounder, we found significantly higher FeNO levels in the EoE cohort than in the control group.

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.

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.

Eosinophilic Esophagitis Symptom Scores Are High in Children Without Eosinophilic Disease

OBJECTIVES

The Pediatric Eosinophilic Esophagitis (EoE) Symptom Score version 2 (PEESSv2.0) is an EoE-specific validated metric for disease monitoring, but its use has not been explored outside of EoE. Our aim was to determine if PEESSv2.0 scores differentiate between children with EoE and non-EoE esophageal dysfunction undergoing initial esophagogastroduodenoscopy (EGD).

METHODS

A prospective cohort study of pediatric subjects was conducted. Children ages 1-18 undergoing initial EGD for esophageal dysfunction were enrolled. Demographics, clinical history, and child self-report and parent-proxy report PEESSv2.0 symptom scores were collected at the time of EGD. Esophageal biopsies were reviewed, and EoE was defined as >15 eosinophils/high powered field (hpf) seen in any level of the esophagus. Non-EoE was defined as <15 eosinophils/hpf.

RESULTS

Seventy-one children were included in the study from 2015 to 2018 [59% (42/71) males; mean age 9.2 years; range 1-17 years]. Fifty-eight percent (41/71) met criteria for EoE, and 42% (30/71) were labeled non-EoE. Non-EoE children and their parents had higher/worse median PEESSv2.0 total scores than those with EoE [47.0 vs 28.0 (P = 0.001) and 40.5 vs 26.5 (P = 0.012), respectively]. Non-EoE children reported higher median GERD [9.0 vs 4.0 (P = 0.003)], nausea/vomiting [9.0 vs 4.0 (P = 0.003)], and pain [11.0 vs 6.0 (P = 0.001)] subdomain scores compared to those with EoE. PEESSv2.0 dysphagia subdomain scores (child and parent-proxy) did not differ between EoE and non-EoE groups [22.0 vs 15.0 (P = 0.184) and 18.5 vs 17.4 (P = 0.330), respectively].

DISCUSSION

Total PEESSv2.0 scores were worse in non-EoE group compared to EoE group. Although PEESSv2.0 is validated for use in monitoring EoE therapy, it does not distinguish children with EoE from non-EoE esophageal dysfunction at the time of diagnostic EGD.

Pediatric eosinophilic esophagitis: a review for the clinician

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

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.

Clinico-pathological characteristics of eosinophilic esophagitis in Jordanian children

Introduction

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated disorder manifested by symptoms of impaired esophageal function and hypereosinophilic esophageal inflammation. It is believed that the number of patients being diagnosed globally is increasing.

Aim

To describe the frequency and clinicopathological features of EoE in Jordanian children.

Material and methods

A retrospective review of all paediatric patients with eosinophilic esophagitis diagnosed and followed up at our paediatric gastroenterology service at King Abdullah University Hospital between January 2015 and January 2020.

Results

During the study period, 21 patients were diagnosed with EoE out of 700 diagnostic endoscopic procedures. Only 1 (4.8%) female was diagnosed. The average age at presentation was 9.5 years (age range: 1-16 years). The most common manifestation was solid food dysphagia (15, 71.4%), followed by food impaction and vomiting (11, 52.4% and 6, 28.6%, respectively). Atopy was diagnosed in 10 (47.6%) patients. Four (19.0%) had food allergy, 3 (14.3%) had respiratory allergy, and 3 (14.3%) had combined. Linear furrows and circular rings were the most common endoscopic features - 17 (81.0%) and 10 (47.6%), respectively, while papillary elongation, basal zone hyperplasia, and eosinophilic infiltrate were the most common reported histopathological features. Almost all patients received proton pump inhibitors (19, 90.5%). Steroids were used in 18 (85.7%) patients; local steroids in 11 (52.4%), and oral steroids in 7 (33.3%). Out of the 4 (19%) patients with esophageal strictures, 2 (9.5%) required pneumatic dilatation.

Conclusions

Eosinophilic esophagitis is not uncommon in our community. Clinical and histological parameters point to delayed referral and diagnosis. Increasing awareness of this problem will lead to early diagnosis and will decrease complications.

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.

Management of Eosinophilic Esophagitis During Oral Immunotherapy

Food allergies are antigen-driven diseases that can lead to IgE-mediated reactions of immediate hypersensitivity (eg, anaphylaxis triggered by a single food) or non-IgE reactions of delayed hypersensitivity such as eosinophilic esophagitis (eg, inability to eat multiple foods manifesting as abdominal pain, choking, dysphagia, vomiting, reflux, food impaction). Although both types of disease have their own unique set of challenges in diagnosis and management, it is a particularly vexing problem when a patient is afflicted by both conditions. This situation can happen when individuals with IgE-mediated food allergy undergo desensitization using currently available forms of oral immunotherapy. In this Grand Rounds Review, we review diagnostic approaches to oral immunotherapy-associated eosinophilic esophagitis, potential relationships between primary and secondary eosinophilic esophagitis, potential management approaches, areas of uncertainty, and upcoming research. Optimally supporting patients in their journey with food allergy requires shared decision making regarding alternative management strategies and the stimulation of robust research.

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.

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.

Noninvasive and minimally invasive techniques for the diagnosis and management of allergic diseases

Allergic diseases of the (upper and lower) airways, the skin and the gastrointestinal tract, are on the rise, resulting in impaired quality of life, decreased productivity, and increased healthcare costs. As allergic diseases are mostly tissue-specific, local sampling methods for respective biomarkers offer the potential for increased sensitivity and specificity. Additionally, local sampling using noninvasive or minimally invasive methods can be cost-effective and well tolerated, which may even be suitable for primary or home care sampling. Non- or minimally invasive local sampling and diagnostics may enable a more thorough endotyping, may help to avoid under- or overdiagnosis, and may provide the possibility to approach precision prevention, due to early diagnosis of these local diseases even before they get systemically manifested and detectable. At the same time, dried blood samples may help to facilitate minimal-invasive primary or home care sampling for classical systemic diagnostic approaches. This EAACI position paper contains a thorough review of the various technologies in allergy diagnosis available on the market, which analytes or biomarkers are employed, and which samples or matrices can be used. Based on this assessment, EAACI position is to drive these developments to efficiently identify allergy and possibly later also viral epidemics and take advantage of comprehensive knowledge to initiate preventions and treatments.

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.

Eosinophilic Esophagitis in Children in North-Eastern Poland

Background: An increase in the incidence of eosinophilic esophagitis worldwide is being observed in children. The aim of the study was to analyze the incidence, clinical manifestations, biochemical markers and endoscopic features of children with eosinophilic esophagitis in comparison to patients with non-eosinophilic esophagitis. Methods: This single-center retrospective study included newly diagnosed children with eosinophilic (EoE) and non-eosinophilic (non-EoE) esophagitis based on endoscopic and histopathological results between January 2013 and December 2018. Result: Among 433 of enrolled children with esophagitis, 36 (8.31%) were diagnosed with EoE (median age of 10 years). Male predominance and an increased percentage of allergy cases in the EoE group were noticed. Dysphagia was the only symptom that significantly differentiated both groups (p = 0.006). Endoscopic findings with relevant relationships with EoE included linear fissuring, decreased vascular pattern, trachealization and whitish exudates. No significant difference in the prevalence of other reported diseases between groups was observed. Conclusion: The results of EoE analysis in children from North-Eastern Poland did not differ from reports from other countries. The reported symptoms were not specific for EoE, and only dysphagia and some endoscopic lesions were helpful to differentiate children with EoE from non-EoE.

Eosinophilic Esophagitis: Existing and Upcoming Therapies in an Age of Emerging Molecular and Personalized Medicine

PURPOSE OF REVIEW

Recent research efforts have spurred great progress in the diagnosis and management of eosinophilic esophagitis (EoE). Nonetheless, challenges remain in addressing disease burden and impairment in the growing EoE population. We highlight work from the Cincinnati Center for Eosinophilic Disorders, the Consortium of Eosinophilic Gastrointestinal Disease Researchers, and others that address these ongoing challenges.

RECENT FINDINGS

New tools for characterizing EoE disease activity include the EoE Histology Scoring System (EoEHSS), endoscopic alternatives, validated patient-reported outcome (PRO) questionnaires, and investigational biomarkers. These diagnostic and monitoring strategies have been complemented by advances in EoE therapy. Treatment modalities have refined the traditional approaches of dietary elimination, swallowed steroids, and proton pump inhibitors (PPI), and biologics offer promise for future treatment. This review summarizes EoE advances in disease management and newly defined EoE endotypes that may serve as the foundation for EoE-personalized medicine.

Monitoring Eosinophilic Esophagitis Disease Activity With Blood Eosinophil Progenitor Levels

OBJECTIVES

A minimally invasive biomarker to monitor disease activity is one of the greatest unmet clinical needs of the pediatric eosinophilic esophagitis (EoE) population. We aimed to determine whether circulating eosinophil progenitors (EoPs) could be used as a biomarker to identify pediatric patients with active EoE.

METHODS

In a prospective observational study, peripheral blood samples, symptom history, and laboratory data were collected from pediatric patients undergoing endoscopy for evaluation of EoE on dietary therapy at Cincinnati Children's Hospital. Peripheral blood EoP level was determined by flow cytometry.

RESULTS

Thirty-four children with active (n = 16) and inactive (n = 18) EoE were included in the analysis. EoP levels in the peripheral blood were 3-fold higher in patients with active EoE than inactive EoE (P < 0.0025). Blood absolute eosinophil count did not distinguish between active and inactive EoE (P = 0.16). A cut-off EoP level ≥17 accurately detected active disease in 79% of patients with 94.4% specificity and 62.5% sensitivity (area under the curve 0.81; P < 0.0024). Antihistamine use lowered the threshold EoP level to detect active EoE.

CONCLUSIONS

This study suggests that blood EoP levels may be used as a biomarker to detect active EoE disease in patients undergoing food trials and potentially reduce the need for repeated endoscopies. Larger prospective studies are needed to investigate the effects of antihistamines and swallowed steroids on EoP mobilization into the peripheral blood and longitudinal studies to assess the performance of the assay in individual patients over time.

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.

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTIONS

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

RESULTS

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

CONCLUSION

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

Molecular, endoscopic, histologic, and circulating biomarker-based diagnosis of eosinophilic gastritis: Multi-site study

BACKGROUND

Eosinophilic gastritis (EG) is a clinicopathologic disorder with marked gastric eosinophilia and clinical symptoms. There is an unmet need among patients with EG for more precise diagnostic tools.

OBJECTIVE

We aimed to develop tissue- and blood-based diagnostic platforms for EG.

METHODS

Patients with EG and control subjects without EG were enrolled across 9 Consortium of Eosinophilic Gastrointestinal Disease Researchers-associated sites. An EG Diagnostic Panel (EGDP; gastric transcript subset) and EG blood biomarker panel (protein multiplex array) were analyzed. EGDP₁₈ scores were derived from the expression of 18 highly dysregulated genes, and blood EG scores were derived from dysregulated cytokine/chemokine levels.

RESULTS

Gastric biopsy specimens and blood samples from 185 subjects (patients with EG, n = 74; control subjects without EG, n = 111) were analyzed. The EGDP (1) identified patients with active EG (P < .0001, area under the curve ≥ 0.95), (2) effectively monitored disease activity in longitudinal samples (P = .0078), (3) highly correlated in same-patient samples (antrum vs body, r = 0.85, P < .0001), and (4) inversely correlated with gastric peak eosinophil levels (r = -0.83, P < .0001), periglandular circumferential collars (r = -0.73, P < .0001), and endoscopic nodularity (r = -0.45, P < .0001). For blood-based platforms, eotaxin-3, thymus and activation-regulated chemokine, IL-5, and thymic stromal lymphopoietin levels were significantly increased. Blood EG scores (1) distinguished patients with EG from control subjects without EG (P < .0001, area under the curve ≥ 0.91), (2) correlated with gastric eosinophil levels (plasma: r = 0.72, P = .0002; serum: r = 0.54, P = .0015), and (3) inversely correlated with EGDP₁₈ scores (plasma: r = -0.64, P = .0015; serum: r = -0.46, P = .0084). Plasma eotaxin-3 levels strongly associated with gastric CCL26 expression (r = 0.81, P < .0001).

CONCLUSION

We developed tissue- and blood-based platforms for assessment of EG and uncovered robust associations between specific gastric molecular profiles and histologic and endoscopic features, providing insight and clinical readiness tools for this emerging rare disease.

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.