Histopathology of the gastric oxyntic mucosa in two different patient groups during long-term treatment with omeprazole

Objectives Hypochlorhydria, hypergastrinaemia, inflammation and Helicobacter pylori infection, dose and duration of omeprazole treatment may separately, or in combination, influence the proliferation of enterochromaffin-like (ECL) cells and parietal cell changes in gastric mucosa. To assess the effects of these variables comparisons were carried out in patients with the acid related Zollinger-Ellison syndrome (ZES) versus patients with progressive systemic sclerosis (PSS) and gastro-oesophageal reflux disease. Methods Twenty-five patients with PSS and 16 patients with ZES were included and received continuous omeprazole treatment for a mean of 7.5 and 9 years. The patients were investigated every 6-12 months with endoscopy, biopsies and histology, and plasma gastrin measurements. PSS patients were titrated by 24 h pH-metry to oesophageal pH>4, and all ZES patients were titrated to a basal acid output of zero H+. Results Changes towards diffuse and linear ECL cell hyperplasia were observed in 41% of the PSS patients. Micronodular hyperplasia and neoplasia were not seen. In the ZES patients changes towards linear and micronodular hyperplasia were observed in all patients. Two patients developed ECL cell carcinoids; one of these had MEN-1 syndrome. Also parietal cell changes were more pronounced in the ZES group than in the PSS group. Conclusions In patients without intrinsic acid hypersecretion and hypergastrinaemia significant proliferation of ECL cells is not an issue irrespective of gastric mucosal inflammation, omeprazole dose, duration of treatment and acid inhibition. The level of gastrin secretion and high plasma gastrin appear to accelerate ECL cell proliferation and parietal cell changes possibly influenced by chronic gastritis and H. pylori infection.