The potential role of the esophageal pre-epithelial barrier components in the maintenance of integrity of the esophageal mucosa in patients with endoscopically negative gastroesophageal reflux disease

OBJECTIVE: Patients with gastroesophageal reflux disease (GERD) accompanied by erosive reflux esophagitis (RE) exhibit an impairment within the esopha geal pre-epithelial barrier protective components that may facilitate the d evelopment and/or progression of the mucosal injury. Little is known, howev er, whether such impairment is a general phenomenon affecting all patients with GERD or whether this is a characteristic feature only of patients with erosive RE. We therefore studied the rate of secretion of esophageal inorg anic and organic protective factors in patients with endoscopically negativ e [E (-)] GERD and compared these results with the corresponding values in asymptomatic volunteers (CTRL). METHODS: The study was conducted on 33 white asymptomatic volunteers and 10 white patients with a long history of GERD confirmed by 24-h pH monitoring and a grossly negative upper endoscopy. Esophageal secretion was collected during mucosal exposure to NaCl, HCl, HC/pepsin and NaCl using the esophag eal perfusion catheter. In collected samples all investigated parameters we re measured. RESULTS: The pH of esophageal secretion and its content of bicarbonate, EGF , and PGE(2) in patients with E (-) GERD and asymptomatic volunteers were s imilar. Unexpectedly, the rate of esophageal glycoconjugate (predominantly mucin) secretion was significantly higher in patients with E (-) GERD than in controls during perfusion with HCl (p < 0.05). Furthermore, secretion of protein in patients with E (-) GERD was significantly higher than in the c ontrol group during the mucosal exposure to HCl/Pepsin (p < 0.05). The nonb icarbonate buffer secretion during perfusion with HCl and HCl/Pepsin as wel l as the rate of esophageal TGF alpha output during infusion of final salin e in patients with E (-) GERD were significantly lower than in CTRL group ( p < 0.05). CONCLUSIONS: Our data indicate that patients with E (-) GERD have an esopha geal secretory potential, in terms of glycoconjugate and protein, higher th an that in asymptomatic controls. This phenomenon in patients with E (-) GE RD may, by enhancing the quantity of the esophageal pre-epithelial barrier, help to prevent the development of erosive esophagitis. A significantly lo wer esophageal secretory response in patients with E (-) GERD in terms of n onbicarbonate buffers and TGF alpha may facilitate the development of GERD symptoms and histological changes of GERD, respectively. (C) 2000 by Am. Ce ll. of Gastroenterology.