Oesophageal baseline impedance values are decreased in patients with eosinophilic oesophagitis

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). Objectives: 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) Omega, p = 0.015), mid-oesophagus (1420 (836-2164) vs. 2614 (2374-3879) Omega, p = 0.003), and proximal oesophagus (1856 (1006-2625) vs. 2868 (2397-3439) Omega, 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