Effects of 5 years of treatment with rabeprazole or omeprazole on the gastric mucosa

Background: Prolonged gastric acid suppression leads to hypergastrinaemia, which promotes hyperplasia of the enterochromaffin-like (ECL) cells of the oxyntic mucosa. The objective was to determine the effects of 5 years of treatment with rabeprazole or omeprazole on the gastric mucosa. Methods: Two hundred and forty-three patients received rabeprazole (20 mg or 10 mg) or omeprazole (20 mg) once daily for up to 5 years, for gastro-oesophageal reflux disease and 51% completed the whole 5 year period. Gastric biopsy specimens were taken and examined for gastritis, Helicobacter pylori infection, and ECL cell status. Findings: H. pylori infection in the gastric corpus was more common than in the antrum, and remained constant, whereas antral H. pylori infection became less common as the study progressed. H. pylori infection was a highly significant predictor of higher gastritis scores, which were similar among the three treatment groups. ECL cell hyperplasia occurred in a minority of patients, and was associated with serum gastrin concentrations. No ECL cell dysplasia or tumours were observed. There were no significant differences among the treatment groups in gastritis or ECL cell hyperplasia grades. Interpretation: This study has confirmed the link between ECL cell hyperplasia and elevated serum gastrin concentrations, but has found no evidence that this progresses to high grades of hyperplasia during 5 years of treatment with rabeprazole or omeprazole.