Cellular proliferation and ploidy of the gastric mucosa : the role of Helicobacter pylori

Background/Aims: Recently, H. pylori has been recognized as a risk factor for gastric adenocarcinoma. As such, we have analyzed the DNA content of gastric epithelial cells in an attempt to reveal the role of H. pylori in gastric carcinogenesis. Methodology: Fifty-three subjects presented with gastric dyspepsia, 39 males and 14 females, with a mean age of 42.15 (±13,16) years. They were referred to the out-patient clinic to undergo endoscopic examination for the first time. Biopsy specimens from the antrum of each subject were subjected to culture for the presence of H. pylori, histologic diagnosis, and DNA flow cytometry for the analysis of cellular proliferation and DNA ploidy. Results: The endoscopic diagnoses were normal appearance (12), Gastric ulcer (12), duodenal ulcer (29). Thirty-eight (72%) subjects were positive, and 15 (28%) subjects were negative for H. pylori. Abnormal DNA-content (aneuploidy) was found in specimens from the antrums of 3 patients, 2 patients with duodenal ulcers (DU) and one with a gastric ulcer (GU). The cellular proliferation as detected by flow cytometry in the form of proliferative index (PI; percentage of cells in the DNA S and G2M phases) was 27.88 (±12.48) and 14.17 (±2.94) in the antrums of those positive and negative for H. pylori, respectively. A very significant increase in the PI (p < 0.005) was found between subjects positive and negative for H. pylori. Patients with DU and H. pylori infection had the highest PI, and the PI was significantly higher than in patients with DU, but without infection. Regarding histology, there was a significant increase in the PI in the presence of H. pylori infection in either CAG or dysplasia groups as compared to cases without infection in the same groups. Conclusion: These results show that H. pylori infection is associated with changes in the DNA-content and cellular proliferative activity, suggesting that H. pylori may be implicated in gastric carcinogenesis. Also, the significant increase in the PI along the progression of severity of the disease suggests that measuring this parameter might allow more accurate monitoring of patients, so that a targeted therapeutic protocol may be defined.