title: Oesophageal baseline impedance values are decreased in patients with eosinophilic oesophagitis.
abstract: BACKGROUND
  Gastro-oesophageal reflux has been suggested to play a role in eosinophilic oesophagitis (EoO). Oesophageal acid exposure decreases baseline intraluminal impedance, a marker of mucosal integrity, in patients with gastro-oesophageal reflux disease (GORD).
  
  
  OBJECTIVE
  The aim of this study was to assess oesophageal baseline impedance levels in EoO patients and to investigate their relationship with oesophageal acid exposure.
  
  
  METHODS
  Ambulatory 24-h pH-impedance monitoring was performed in 11 EoO patients and in 11 healthy controls with matched oesophageal acid exposure. We assessed baseline impedance levels in the distal, mid-, and proximal oesophageal impedance channels.
  
  
  RESULTS
  BASELINE IMPEDANCE LEVELS IN EOO PATIENTS WERE MARKEDLY LOWER COMPARED TO CONTROLS IN THE DISTAL OESOPHAGUS (MEDIAN (INTERQUARTILE RANGE): 988 (757-1978) vs. 2259 (1767-2896) Ω, p = 0.015), mid-oesophagus (1420 (836-2164) vs. 2614 (2374-3879) Ω, p = 0.003), and proximal oesophagus (1856 (1006-2625) vs. 2868 (2397-3439) Ω, p = 0.005). Whereas baseline impedance decreased from proximal to distal in healthy subjects (p = 0.037), no such gradient was seen in EoO patients (p = 0.123).
  
  
  CONCLUSIONS
  Throughout the oesophagus, baseline impedance values are decreased in EoO patients, indicating impaired mucosal integrity. Our findings suggest that factors other than acid reflux are the cause of low baseline impedance in EoO.
authors.affiliation: Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Bram D
authors.initials: BD
authors.lastname: van Rhijn
authors.affiliation: Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Boudewijn F
authors.initials: BF
authors.lastname: Kessing
authors.affiliation: Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Andreas Jpm
authors.initials: AJ
authors.lastname: Smout
authors.affiliation: Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Bredenoord
keywords: Aetiology; EoO; RDQ; ambulatory 24-h ph-impedance monitoring; atopy; baseline impedance; follow up; gastro-oesophageal reflux; mucosal integrity; pathophysiology