Increased expression of proton pump and allergic inflammation genes predicts PPI failure in pediatric eosinophilic esophagitis.

Proton pump inhibitors (PPIs) are one of the standards of care of eosinophilic esophagitis (EoE) treatment, though PPI response rates are variable ranging from 23 to 63% in pediatric studies. We sought to determine if expression of select genes in esophageal mucosa can predict PPI responsiveness in EoE. Children with a new diagnosis of EoE (15 or more eosinophils/hpf on esophageal biopsy) were prospectively treated with 8 weeks of PPI therapy before follow-up esophagogastroduodenoscopy (EGD). Children with <15 eosinophils/hpf on follow-up were classified as having PPI-Responsive EoE (PPI-R) and ≥ 15 eosinophils/hpf as PPI-Nonresponsive EoE (PPI-NR). Using the Nanostring nCounter Analysis System, mRNA expression of a custom panel of genes was measured in esophageal biopsies. Immunohistochemical staining of biopsies was performed. Among children with EoE, 32% (8/25) had PPI-R EoE. ATP12A, ATP4A, tryptase-beta 2 (TPSB2), CLC and IL13 had higher expression in PPI-NR EoE compared to PPI-R EoE or controls. Immunohistochemical staining of ATP12A was higher among PPI-R EoE and PPI-NR EoE, compared to non-EoE controls. In this study, PPI-NR EoE had significantly higher baseline gene expression of mast cell, cytokine, proton pump, and eosinophil genes compared to PPI-R EoE. PPIs may be involved in an inflammatory cascade of mast cell activation that stimulates IL-13 release, which upregulates ATP12A and ATP4A that leads to eosinophil recruitment. Histologic PPI failure may occur when increased gene expression of these components is high and cannot be overcome pharmacologically, especially in the case of proton pump genes.

Bose P ，Zhang W ，Mehrpouya-Bahrami P ，Collins K ，Zhao J ，Cannon AM ，Albright E ，Idrees MT ，Perkins A ，Gupta SK ，Hon EC ，Kaplan MH ... -  《-》

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

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. 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. 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. 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.

Molina-Jiménez F ，Ugalde-Triviño L ，Arias-González L ，Armenteros E ，Relaño-Rupérez C ，Casabona S ，Moreno-Monteagudo JA ，Pérez-Fernández MT ，Martín-Domínguez V ，Fernández-Pacheco J ，Laserna-Mendieta EJ ，Muñoz-Hernández P ，García-Martínez J ，Muñoz J ，Lucendo AJ ，Santander C ，Majano P ... -  《-》

Children with eosinophilic esophagitis non-responsive to combination therapy have distinct esophageal transcriptomic and microbiome profile.

A combination of proton-pump inhibitors (PPI) and topical steroids (TS) is used to treat children with eosinophilic esophagitis (EoE). However, a subset of children do not respond to this combination therapy. We aimed to identify the esophageal transcriptional, cell composition, and microbial differences between the non-responders (EoE-PPI-TSnr; n = 7) and responders (EoE-PPI-TSr; n = 7) to the combination therapy for EoE and controls (n = 9) using metatranscriptomics. Differential gene expression analysis was used to identify transcriptional differences, validated using the EoE diagnostic panel (EDP). Deconvolution analysis was performed to identify differences in their cell type composition. Microbiome analysis was conducted from esophageal biopsies RNAseq data, and microbial abundance was correlated with esophageal gene expression. In all, 3164 upregulated and 3154 downregulated genes distinguished EoE-PPI-TSnr from EoE-PPI-TSr. Eosinophilic inflammatory response, cytokine signaling, and collagen formation pathways were significantly upregulated in EoE-PPI-TSnr. There was a 56% overlap in dysregulated genes between EoE-PPI-TSnr and EDP, with a perfect agreement in the directionality of modulation. Eosinophils, dendritic cells (DCs), immature DCs, megakaryocytic-erythroid progenitors, and T helper type 1 cells were significantly higher in EoE-PPI-TSnr. There was no significant difference in microbiome diversity. The relative abundance of Fusobacterium sp. and Acinetobacter sp. notably differed in EoE-PPI-TSnr and correlated with the key pathways. Our results provide critical insights into the molecular, cellular, and microbial factors associated with the lack of response to PPI and TS combination therapy in children with EoE. This study advances our understanding of the pathobiology of EoE while guiding personalized treatment strategies.

Hiremath G ，Choksi Y ，Correa H ，Jacobse J ，Das SR ，Ma S ，Goettel JA ，Rajagopala SV ... -  《-》

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

Muftah M ，Hartnett DA ，Flanagan R ，Redd WD ，Jenkins A ，Goldin AH ，Hsu Blatman K ，Chan WW ... -  《-》

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

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. 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. 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. 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.

Ugalde-Triviño L ，Molina-Jiménez F ，H-Vázquez J ，Relaño-Rupérez C ，Arias-González L ，Casabona S ，Pérez-Fernández MT ，Martín-Domínguez V ，Fernández-Pacheco J ，Lucendo AJ ，Bernardo D ，Santander C ，Majano P ... -  《Frontiers in Immunology》