Helicobacter pylori vacA and cagA genotype diversity and interferon gamma expression in patients with chronic gastritis and patients with gastric cancer

Abstract

Background: Helicobacter pylori (H. pylori) is the main risk factor for the development of chronic gastritis, gastric ulcer, and gastric cancer. In H. pylori-infected individuals, the clinical result is dependent on various factors, among which are bacterial components, the immune response, and environmental influence. Aims: To compare IFN-γ expression with the H. pylori vacA and cagA genotypes in patients with chronic gastritis and patients with gastric cancer. Methods: Ninety-five patients diagnosed with chronic gastritis and 20 with gastric cancer were included in the study. Three gastric biopsies were taken; one was used for the molecular detection and genotyping of H. pylori; another was fixed in absolute alcohol and histologic sections were made for determining IFN-γ expression through immunohistochemistry. Results: No differences were found in the cells that expressed IFN-γ between the patients with chronic gastritis (median percentage of positive cells: 82.6% in patients without H. pylori and 82% in infected persons) and those with gastric cancer (70.5% in H. pylori-negative patients and 78.5% in infected persons). IFN-γ expression was 69% in chronic gastritis patients infected with H. pylori vacAs2m2/cagA− it was 86.5% in patients infected with H. pylori vacAs1m2/cagA-, 86.5% in vacAs1m1/cagA−, and 82% in vacAs1m1/cagA+. Similar data were found in the patients with gastric cancer. Conclusions: IFN-γ expression varied depending on the H. pylori vacA and cagA genotype, but not in accordance with the presence of chronic gastritis or gastric cancer.

Keywords

• Helicobacter pylori
• cagA
• vacA
• Interferon gamma
• Gastric cancer