BackgroundPatients with Eosinophilic esophagitis (EoE) require long-lasting resolution of inflammation to prevent fibrostenosis and dysphagia. However, the dissociation between symptoms and histologic improvement suggests persistent molecular drivers despite histologic remission. ObjectiveTo characterize persisting molecular alterations in pediatric patients with EoE using tissue transcriptomics and proteomics. MethodsEsophageal biopsies (n=247) collected prospectively during 189 endoscopies from pediatric patients with EoE (N=36, up to 11 follow-up endoscopies) and pediatric controls (N=44, single endoscopies) were subjected to bulk transcriptomics (n=96) and proteomics (n=151). Intercellular junctions (Desmoglein-1/-3, Desmoplakin, E-cadherin) and epithelial-to-mesenchymal transition (EMT, Vimentin:E-cadherin ratio) were assessed by immunofluorescence staining. ResultsActive EoE (≥15 eosinophils/hpf), inactive EoE (<15 eosinophils/hpf) and deep remission EoE (0 eosinophils/hpf) were diagnosed in 107/185, 78/185 and 41/185 biopsies, respectively. Among the dysregulated genes (up-/downregulated 310/112) and proteins (up-/downregulated 68/16) between active EoE and controls, 17 genes and 6 proteins remained dysregulated in inactive EoE. Using persistently upregulated genes (n=9) and proteins (n=3) only, such as ALOX15, CXCL1, CXCL6, CTSG, CDH26, PRRX1, CLC, EPX, and POSTN was sufficient to separate inactive EoE, as well as deep remission biopsies from control tissue. While 32 differentially expressed genes persisted in deep remission of EoE compared to controls, the proteome normalized except for persistently upregulated Periostin (POSTN). Epithelial-mesenchymal transition normalized in inactive EoE, whereas desmosome recovery remained impaired due to Desmoglein-1 downregulation. ConclusionThe analysis of molecular changes shows persistent EoE-associated esophageal dysregulation despite histologic remission. These data expand our understanding of inflammatory processes and possible mechanisms that underlie tissue remodeling in EoE.
Read full abstract