Gastric epithelial proliferation and p53 and p21 expression in a general population sample: relations to age, sex, and mucosal changes associated with H. pylori infection.

Helicobacter pylori infection is the main cause of chronic gastritis. The infection has been linked to altered proliferative activity and changes in various cell cycle regulating proteins. To determine, in a general population sample, the proliferative activity and expression of p53 and p21 in males and females of different age groups with and without H. pylori-associated chronic gastritis, gastric biopsies from 273 subjects (188 with and 85 without H. pylori infection) randomly selected from a general population were examined immunohistochemically for Ki-67, p53, and p21. One thousand epithelial cells, including the surface, neck, and glandular areas, were counted in both the corpus and the antrum. Results are expressed as the percentage of positive cells. Subjects with H. pylori infection showed significantly increased proliferative activity and expression of p53 compared to uninfected individuals. Regarding the expression of p21, no difference was detected. Multiple linear regression analysis showed significant associations between chronic inflammation or inflammatory activity, on the one hand, and the degree of proliferation in both the corpus and the antrum, on the other hand. In the antrum, the degree of H. pylori colonization was related to the expression of p53. H. pylori seems to cause increased proliferation and increased expression of p53 (but not p21) in the gastric mucosa, neither of which is age or sex dependent. The proliferative activity is related mainly to events associated with inflammation, while the expression of p53 in the antrum is associated with the degree of H. pylori infection. The action of p53 appears to be independent of p21 activity.