Effect of Helicobacter pylori infection, age and epithelial cell turnover in a general population at high risk for gastric cancer

Abstract

Background: H. pylori and age are two known risk factors for atrophic gastritis and high epithelial cell turnover may be an indicator for preneoplastic changes in the stomach. We searched for an association between H. pylori, age and gastritis in the general population together with the proliferative state into the antral mucosa.

Methods: We examined gastric biopsies from antrum and corpus of 117 consecutive volunteers which were endoscoped during a population study in San Marino. H. pylori status was determined by serum IgG antibodies, rapid urease test on biopsies and histology. Presence of gastritis and grading of inflammation, activity, intestinal metaplasia and atrophy were ascertained using Sydney System. On a subsample of 36 subjects without endoscopic lesions we performed an immunohistochemical study on gastric cell proliferation using PCNA. A computer-aided count was made on stained epithelial cells to evaluate labeling index. Statistical analysis was performed using chi 2 test and linear regression.

Results: Inflammatory infiltrate (both activity and mononuclear cells), (p < 0.0001) and intestinal metaplasia (p < 0.004) were significantly higher in H. pylori positive subjects. Atrophic gastritis was present in 82% H. pylori positive subjects vs 17.6% (p < 0.0001). Labeling Index was significantly higher in H. pylori positive subjects (p < 0.005) and it was correlated with inflammation and atrophy (p = 0.001). Elderly H. pylori negative subjects have a lower cell turnover (p = 0.006) but H. pylori infected subjects do not show any decrease of Labeling Index with age.

Conclusions: In the general population of an area with high gastric cancer rate, H. pylori infection is associated with atrophic gastritis and with hyperproliferative gastric cell state. These conditions are present either in young and old age and increase the neoplastic risk of gastric mucosa.