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In vivo evaluation of acid-induced changes in oesophageal mucosa integrity and sensitivity in non-erosive reflux disease
  1. Philip Woodland,
  2. Mohannad Al-Zinaty,
  3. Etsuro Yazaki,
  4. Daniel Sifrim
  1. Neurogastroenterology Group, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK
  1. Correspondence to Dr Daniel Sifrim, The Wingate Institute of Neurogastroenterology, 26 Ashfield Street, London E1 2AJ, UK; d.sifrim{at}


Objective Patients with non-erosive reflux disease (NERD) have impaired oesophageal mucosal integrity (dilated intercellular spaces). Oesophageal mucosal integrity reflects the balance between repeated reflux damage and mucosal recovery. The relationship between mucosal integrity and acid sensitivity is unclear. Oesophageal impedance may be used for in vivo mucosal integrity measurement. We studied acid-induced changes in oesophageal mucosal integrity and acid perception in patients with heartburn.

Design 50 patients with heartburn whithout oesophagitis underwent impedance monitoring before, during and after 10 min oesophageal perfusion with neutral (pH6.5) and acid solutions (pH1). Symptoms and impedance were recorded during perfusion. Impedance recovery was assessed for 2 h post-perfusion in ambulatory conditions followed by 24-h impedance-pH study.

Results Reflux monitoring discriminated 20 NERD and 30 functional heartburn (FH) patients. Neutral perfusion caused impedance fall that recovered within 10 min. Acid perfusion caused impedance fall with slow recovery: 6.5 Ω/min (IQR 3.3-12.0 Ω/min). Patients with slow recovery (<25th percentile) had lower baseline impedance (1273 Ω ±208 Ω vs. 3220 Ω ±275 Ω ±, p < 0.01) and more frequent acid sensitivity (10/12 vs. 4/12, p = 0.04) than those with fast (>75th percentile) recovery. Patients with NERD had lower baseline impedance (1669 ± 182 Ω vs. 2384 ± 211 Ω, p = 0.02) and slower impedance recovery (6.0 ± 0.9 Ω/min vs. 10.7 ± 1.6 Ω/min, p = 0.03) than patients with FH.

Conclusion Impaired mucosal integrity might be the consequence of repeated reflux episodes with slow recovery. Mucosal integrity, recovery capacity and symptom perception are linked. Low basal impedance and slow recovery after acid challenge are associated with increased acid sensitivity.

  • Gastro-oesophageal reflux disease
  • oesophageal mucosa
  • oesophageal impedance
  • oesophageal reflux
  • oesophageal physiology
  • endoscopic ultrasonography
  • acid-related diseases
  • adenocarcinoma
  • anti-reflux therapy
  • Barrett's oesophagus
  • gastrointestinal motility
  • dysphagia
  • erosive oesophagitis
  • mucosal barrier
  • neurogastroenterology

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  • Funding Grant support: DS receives a grant from the Medical Research Council for Translational Research in Neurogastroenterology; grant number: MGAB1A7R. DS receives a research grant from Sandhill Scientific, USA.

  • Competing interests Philip Woodland, Mohannad Al-Zinaty and Etsuro Yazaki have no conflicts of interest to declare. Daniel Sifrim receives a research grant from Sandhill Scientific, USA.

  • Provenance and peer review Not commissioned; externally peer reviewed.