title: Proton pump inhibitor-responsive oesophageal eosinophilia and eosinophilic oesophagitis: more similarities than differences.
abstract: OBJECTIVE
  The purpose of this study is to discuss the clinical, endoscopic and histologic features, pathogenesis and disease mechanisms of proton pump inhibitor (PPI)-responsive oesophageal eosinophilia (PPI-REE), and to highlight similarities and differences with eosinophilic oesophagitis (EoE).
  
  
  RESULTS
  PPI-REE is a condition in which patients have clinical and histologic findings similar to EoE, but achieve complete remission with PPI treatment. More than one-third of patients who have oesophageal symptoms associated with oesophageal eosinophilia respond to PPI treatment. Emerging data elucidating the pathogenesis of PPI-REE have shown that Th2-related inflammatory factors such as interleukin (IL)-13, IL-5, eotaxin-3 and major basic protein (MBP) are elevated in PPI-REE, similar to EoE. PPI-REE also shares a genetic expression signature with EoE that reverses with PPI treatment. Mechanisms proposed to explain the PPI response include an acid-independent, anti-inflammatory action of PPIs and PPI-induced restoration of oesophageal barrier function.
  
  
  CONCLUSIONS
  Multiple features of PPI-REE overlap extensively with EoE. This raises the question of whether PPI-REE is merely a subtype of EoE rather than an independent condition. This similarity may have future implications for algorithms informing evaluation and treatment of oesophageal eosinophilia.
authors.affiliation: aCenter for Esophageal Diseases and Swallowing bCenter for Gastrointestinal Biology and Disease, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
authors.forename: Swathi
authors.initials: S
authors.lastname: Eluri
authors.forename: Evan S
authors.initials: ES
authors.lastname: Dellon
mesh_terms: D057765:Eosinophilic Esophagitis / Q000175:diagnosis / Q000188:drug therapy* / Q000235:genetics; D050782:Esophageal pH Monitoring / Q000379:methods; D004945:Esophagoscopy / Q000379:methods; D005764:Gastroesophageal Reflux / Q000175:diagnosis; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D011379:Prognosis; D054328:Proton Pump Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D054328:Proton Pump Inhibitors