Impact of STAT6 Variants on the Response to Proton Pump Inhibitors and Comorbidities in Patients with Eosinophilic Esophagitis.

Proton pump inhibitors (PPIs) are the first-line drug for eosinophilic esophagitis (EoE), although it is estimated that there is a lack of histological remission in 50% of patients. This research aimed to identify pharmacogenetic biomarkers predictive of PPI effectiveness and to study their association with disease features. Peak eosinophil count (PEC) and the endoscopic reference score (EREFS) were determined before and after an eight-week PPI course in 28 EoE patients. The impact of the signal transducer and activator of transcription 6 (STAT6), CYP2C19, CYP3A4, CYP3A5, and ABCB1 genetic variations on baseline PEC and EREFS, their reduction and histological response, and on EoE symptoms and comorbidities was analyzed. PEC reduction was higher in omeprazole-treated patients (92.5%) compared to other PPIs (57.9%, p = 0.003). STAT6 rs12368672 (g.18453G>C) G/G genotype showed higher baseline PEC values compared to G/C and C/C genotypes (83.2 vs. 52.9, p = 0.027). EREFS reduction in STAT6 rs12368672 G/G and G/C genotypes was higher than in the C/C genotype (36.7% vs. -75.0% p = 0.011). However, significance was lost after Bonferroni correction. Heartburn incidence was higher in STAT6 rs167769 (g.27148G>A) G/G patients compared to G/A (54.55% vs. 11.77%, p = 0.030). STAT6 rs12368672G>C and rs167769G>A variants might have a relevant impact on EoE status and PPI response. Further research is warranted to clarify the clinical relevance of these variants.

Circulating immunome fingerprint in eosinophilic esophagitis is associated with clinical response to proton pump inhibitor treatment.

Objectives: The aim of the study was to characterize the circulating immunome of patients with EoE before and after proton pump inhibitor (PPI) treatment in order to identify potential non-invasive biomarkers of treatment response. Methods: PBMCs from 19 healthy controls and 24 EoE patients were studied using a 39-plex spectral cytometry panel. The plasmacytoid dendritic cell (pDC) population was differentially characterized by spectral cytometry analysis and immunofluorescence assays in esophageal biopsies from 7 healthy controls and 13 EoE patients. Results: Interestingly, EoE patients at baseline had lower levels of circulating pDC compared with controls. Before treatment, patients with EoE who responded to PPI therapy had higher levels of circulating pDC and classical monocytes, compared with non-responders. Moreover, following PPI therapy pDC levels were increased in all EoE patients, while normal levels were only restored in PPI-responding patients. Finally, circulating pDC levels inversely correlated with peak eosinophil count and pDC count in esophageal biopsies. The number of tissue pDCs significantly increased during active EoE, being even higher in non-responder patients when compared to responder patients pre-PPI. pDC levels decreased after PPI intake, being further restored almost to control levels in responder patients post-PPI. Conclusions: We hereby describe a unique immune fingerprint of EoE patients at diagnosis. Moreover, circulating pDC may be also used as a novel non-invasive biomarker to predict subsequent response to PPI treatment.

Long Non-Coding RNA Signatures in the Ileum and Colon of Crohn's Disease Patients and Effect of Anti-TNF-α Treatment on Their Modulation.

Biological therapies only benefit one-third of patients with Crohn's disease (CD). For this reason, a deeper understanding of the mechanisms by which biologics elicit their effect on intestinal mucosa is needed. Increasing evidence points toward the involvement of long noncoding RNAs (lncRNAs) in the pathogenesis of CD, although their role remains poorly studied. We aimed to characterize lncRNA profiles in the ileum and colon from CD patients and evaluate the effect of anti-TNF-α treatment on their transcription. Terminal ileum and left colon samples from 30 patients (active CD = 10, quiescent CD = 10, and healthy controls (HCs) = 10) were collected for RNA-seq. The patients were classified according to endoscopic activity. Furthermore, biopsies were cultured with infliximab, and their transcriptome was determined by Illumina gene expression array. A total of 678 differentially expressed lncRNAs between the terminal ileum and left colon were identified in HCs, 438 in patients with quiescent CD, and 468 in patients with active CD. Additionally, we identified three new lncRNAs in the ileum associated with CD activity. No differences were observed when comparing the effect of infliximab according to intestinal location, presence of disease (CD vs. HC), and activity (active vs. quiescent). The expression profiles of lncRNAs are associated with the location of intestinal tissue, being very different in the ileum and colon. The presence of CD and disease activity are associated with the differential expression of lncRNAs. No modulatory effect of infliximab has been observed in the lncRNA transcriptome.

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.

Differential Effects of Anti-TNFα and Anti-α4ß7 Drugs on Circulating Dendritic Cells Migratory Capacity in Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is an idiopathic and chronic disorder that includes ulcerative colitis (UC) and Crohn's disease (CD). Both diseases show an uncontrolled intestinal immune response that generates tissue inflammation. Dendritic cells (DCs) are antigen-presenting cells that play a key role in tolerance maintenance in the gastrointestinal mucosa. Although it has been reported that DC recruitment by the intestinal mucosa is more prominent in IBD patients, the specific mechanisms governing this migration are currently unknown. In this study, the expression of several homing markers and the migratory profile of circulating DC subsets towards intestinal chemo-attractants were evaluated and the effect of biological drugs with different mechanisms of action, such as anti-TNFα or anti-integrin α4ß7 (vedolizumab), on this mechanism in healthy controls (HCs) and IBD patients was also assessed. Our results revealed that type 2 conventional DCs (cDC2) express differential homing marker profiles in UC and CD patients compared to HCs. Indeed, integrin ß7 was differentially modulated by vedolizumab in CD and UC. Additionally, although CCL2 displayed a chemo-attractant effect over cDC2, while biological therapies did not modulate the expression of the homing markers, we paradoxically found that anti-TNF-treated cDC2 increased their migratory capacity towards CCL2 in HCs and IBD. Our results therefore suggest a key role for cDC2 migration towards the intestinal mucosa in IBD, something that could be explored in order to develop novel diagnostic biomarkers or to unravel new immunomodulatory targets in IBD.

Accurate and timely diagnosis of Eosinophilic Esophagitis improves over time in Europe. An analysis of the EoE CONNECT Registry.

BACKGROUND: Poor adherence to clinical practice guidelines for eosinophilic esophagitis (EoE) has been described and the diagnostic delay of the disease continues to be unacceptable in many settings. OBJECTIVE: To analyze the impact of improved knowledge provided by the successive international clinical practice guidelines on reducing diagnostic delay and improving the diagnostic process for European patients with EoE. METHODS: Cross-sectional analysis of the EoE CONNECT registry based on clinical practice. Time periods defined by the publication dates of four major sets of guidelines over 10 years were considered. Patients were grouped per time period according to date of symptom onset. RESULTS: Data from 1,132 patients was analyzed and median (IQR) diagnostic delay in the whole series was 2.1 (0.7-6.2) years. This gradually decreased over time with subsequent release of new guidelines (p < 0.001), from 12.7 years up to 2007 to 0.7 years after 2017. The proportion of patients with stricturing of mixed phenotypes at the point of EoE diagnosis also decreased over time (41.3% vs. 16%; p < 0.001), as did EREFS scores. The fibrotic sub-score decreased from a median (IQR) of 2 (1-2) to 0 (0-1) when patients whose symptoms started up to 2007 and after 2017 were compared (p < 0.001). In parallel, symptoms measured with the Dysphagia Symptoms Score reduced significantly when patients with symptoms starting before 2007 and after 2012 were compared. A reduction in the number of endoscopies patients underwent before the one that achieved an EoE diagnosis, and the use of allergy testing as part of the diagnostic workout of EoE, also reduced significantly over time (p = 0.010 and p < 0.001, respectively). CONCLUSION: The diagnostic work-up of EoE patients improved substantially over time at the European sites contributing to EoE CONNECT, with a dramatic reduction in diagnostic delay.

Proton pump inhibitor therapy reverses endoscopic features of fibrosis in eosinophilic esophagitis.

BACKGROUND: Long-standing inflammation leads to esophageal remodeling with stricture formation in patients with eosinophilic esophagitis (EoE). The ability of proton pump inhibitors (PPI) to reverse endoscopic features of fibrosis is still unknown. OBJECTIVE: To investigate the effect of a short course of PPI treatment in reducing endoscopic findings indicative of esophageal fibrosis in EoE patients. METHODS: Cross-sectional analysis of the EoE CONNECT registry. Patients who received PPI to induce EoE remission were evaluated. Endoscopic features were graded using the EoE Endoscopic Reference Score (EREFS), with rings and strictures indicating fibrosis. Results were compared to those from patients treated with swallowed topic corticosteroids (STC). RESULTS: Clinico-histological remission was achieved in 83/166 adult patients treated with PPI (50%) and in 65/79 (82%) treated with STC; among responders, 60 (36%) and 57 (72%) patients respectively achieved deep histological remission (<5 eosinophils/hpf). At baseline, mean±SD EREFS was lower in patients treated with PPI compared to those who received STC (p < 0.001). Short term treatment significantly reduced EREFS scores in patients treated either with PPI or STC as well as rings and strictures. Among patients treated with PPI, deep histological remission (<5 eosinophils/hpf) provided further reduction in total EREFS score. CONCLUSION: Effective PPI therapy for EoE significantly reduced endoscopic esophageal fibrosis in the short term.

Efficacy of proton pump inhibitor therapy for eosinophilic oesophagitis in 630 patients: results from the EoE connect registry.

BACKGROUND: Proton pump inhibitors (PPIs) are the most commonly used first-line therapy for patients with eosinophilic oesophagitis (EoE). However, many aspects related to PPIs in EoE are still unknown. AIMS: To assess the effectiveness of PPI therapy for EoE in real-world practice. METHODS: This cross-sectional study collected data on PPI efficacy from the multicentre EoE CONNECT database. Clinical remission was defined as a decrease of ≥50% in dysphagia symptom score; histological remission was defined as a peak eosinophil count below 15 eosinophils per high-power field. Factors associated with effectiveness of PPI therapy were identified by binary logistic regression multivariate analyses. RESULTS: Overall, 630 patients (76 children) received PPI as initial therapy (n = 600) or after failure to respond to other therapies (n = 30). PPI therapy achieved eosinophil density below 15 eosinophils per high-power field in 48.8% and a decreased symptom score in 71.0% of patients. More EoE patients with an inflammatory rather than stricturing phenotype accomplished clinico-histological remission after PPI therapy (OR 3.7; 95% CI, 1.4-9.5); as well as those who prolonged treatment length from 8 to 12 weeks (OR 2.7; 95% CI, 1.3-5.3). After achieving clinico-histological remission of EoE, PPI dosage reduction was effectively maintained in 69.9% of patients, but tended to be less effective among those with a stricturing phenotype. CONCLUSIONS: Inflammatory EoE phenotype and treatment duration up to 12 weeks correlated with greater chance for inducing remission of EoE. A stricturing phenotype decreased response rates to PPI therapy both initially and in the long term.

Efficacy of Therapy for Eosinophilic Esophagitis in Real-World Practice.

BACKGROUND & AIMS: Topical steroids, proton pump inhibitors (PPIs), and dietary interventions are recommended first- and second-line therapies for eosinophilic esophagitis (EoE). We investigated differences in their effectiveness in a real-world, clinical practice cohort of patients with EoE. METHODS: We collected data on the efficacy of different therapies for EoE (ability to induce clinical and histologic remission) from the multicenter EoE CONNECT database-a database of patients with a confirmed diagnosis of EoE in Europe that began in 2016. We obtained data from 589 patients, treated at 11 centers, on sex, age, time of diagnosis, starting date of any therapy, response to therapy, treatment end dates, alternative treatments, and findings from endoscopy. The baseline endoscopy was used for diagnosis of EoE; second endoscopy was performed to evaluate response to first-line therapies. After changes in treatment, generally because lack of efficacy, a last endoscopy was performed. The time elapsed between endoscopies depended on the criteria of attending physicians. Clinical remission was defined by a decrease of more than 50% in Dysphagia Symptom Score; improvement in symptoms by less than 50% from baseline was considered as clinical response. Histologic remission was defined as a peak eosinophil count below 5 eosinophils/hpf. A peak eosinophil count between 5 and 14 eosinophils/hpf was considered histologic response. We identified factors associated with therapy selection and effectiveness using χ2 and multinomial logistic regression analyses RESULTS: PPIs were the first-line treatment for 76.4% of patients, followed by topical steroids (for 10.5%) and elimination diets (for 7.8%). Topical steroids were most effective in inducing clinical and histologic remission or response (in 67.7% of patients), followed by empiric elimination diets (in 52.0%), and PPIs (in 50.2%). Among the 344 patients who switched to a second-line therapy, dietary interventions were selected for 47.1% of patients, followed by PPIs (for 29.1%) and topical steroids (for 18.6%). Clinical and histologic remission or response was achieved by 80.7% of patients treated with topical steroids, 69.2% of patients given PPIs, and 41.7% of patients on empiric elimination diets. Multivariate analyses found the stricturing phenotype of EoE to be associated with selection of topical steroids over PPIs as the first-line therapy; lack of fibrotic features at initial endoscopy was associated with selection of elimination diets over topical steroids as a second-line therapy. The recruiting center was significantly associated with therapy choice; second-line treatment with topical steroids or PPIs were the only variables associated with clinical and histologic remission. CONCLUSIONS: In an analysis of data from a large cohort of patients with EoE in Europe, we found topical steroids to be the most effective at inducing clinical and histologic remission, but PPIs to be the most frequently prescribed. Treatment approaches vary with institution and presence of fibrosis or strictures.