Helicobacter pylori strain types and risk of gastric cancer: A case-control study

The aim of this: novel endoscopy clinic-based case-control study war, to ex plore the influence of different Helicobacter pylori strain types on the ri sk of gastric adenocarcinoma using isolated bacterial strains, tissue sampl es, and sera. We included 72 cases with gastric adenocarcinoma and 324 age- and sex-matched controls. Histological characterization, culture, molecular typing of Ii pylori genes by PCR (cagA/vacA), conventional Ige ELISA, and immunoblotting (Western blot) for the CagA and VacA proteins were performed , With four tests combined, Ii pylori infection was detected in 57 (79%) ca ses acid 213 (66%) controls, A positive association between ii pylori infec tion and gastric cancer risk was found [odds ratio (OR), 2.1; 95% confidenc e interval, 1.1-3.9], Type I(OR, 1.8), intermediate (OR, 2.0), and type II (OR, 0.2) strains of Ii, pylori presented different serum antibody levels a nd different levels of association with gastric cancer. Our case-control st udy, based on molecular characterization and serology, provides further evi dence that infection by more virulent strains of H, pylori and the presence of antibodies toward the CagA protein can be used as markers for an increa sed risk of gastric adenocarcinoma and that the strain types of Ii pylori c ould be used in the future to determine disease outcome.