AIMS: To characterize the variation in virulence of Helicobacter pylori associated with CagA Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs, and to explore its relationship with the histopathological features of chronic gastritis and with the development of gastric carcinoma. METHODS AND RESULTS: A total of 169 H. pylori-infected patients with chronic gastritis and gastric carcinoma were studied. The presence of cagA and the number and type of EPIYA motifs were determined by polymerase chain reaction. Infection with strains harbouring two or more CagA EPIYA C motifs was associated with the presence of surface epithelial damage, and with atrophic gastritis and gastric carcinoma. The magnitude of risk for atrophic gastritis and gastric carcinoma increased with increasing number of EPIYA C motifs: strains with one EPIYA C motif conferred a risk (odds ratio [OR]) of 7.3 [95% confidence interval (CI) 2.1-25] for atrophic gastritis, whereas strains with two or more EPIYA C motifs conferred a risk (OR) of 12 (95% CI 2.5-58); strains with one EPIYA C motif conferred a risk (OR) of 17 (95% CI 5.4-55) for gastric carcinoma, whereas strains with two or more EPIYA C motifs conferred a risk (OR) of 51 (95% CI 13-198). CONCLUSIONS: Characterization of the number of H. pylori EPIYA C motifs is important in better defining gastric carcinoma risk.
AIMS: To characterize the variation in virulence of Helicobacter pylori associated with CagA Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs, and to explore its relationship with the histopathological features of chronic gastritis and with the development of gastric carcinoma. METHODS AND RESULTS: A total of 169 H. pylori-infectedpatients with chronic gastritis and gastric carcinoma were studied. The presence of cagA and the number and type of EPIYA motifs were determined by polymerase chain reaction. Infection with strains harbouring two or more CagA EPIYA C motifs was associated with the presence of surface epithelial damage, and with atrophic gastritis and gastric carcinoma. The magnitude of risk for atrophic gastritis and gastric carcinoma increased with increasing number of EPIYA C motifs: strains with one EPIYA C motif conferred a risk (odds ratio [OR]) of 7.3 [95% confidence interval (CI) 2.1-25] for atrophic gastritis, whereas strains with two or more EPIYA C motifs conferred a risk (OR) of 12 (95% CI 2.5-58); strains with one EPIYA C motif conferred a risk (OR) of 17 (95% CI 5.4-55) for gastric carcinoma, whereas strains with two or more EPIYA C motifs conferred a risk (OR) of 51 (95% CI 13-198). CONCLUSIONS: Characterization of the number of H. pylori EPIYA C motifs is important in better defining gastric carcinoma risk.