The association of polymorphisms in virulence factor of Helicobacter pylori and gastroduodenal diseases in South Korea

Abstract

Background: Helicobacter pylori (H. pylori) has been suggested to be associated with development of several gastroduodenal diseases. Clinical outcomes of H. pylori infection have been shown to be dependent on the variability of virulence factors in addition to host and environmental factors. Aims: The aims of this study were to evaluate the prevalence of each virulence factor and the association between polymorphisms in virulence factors of H. pylori and clinical outcome of gastroduodenal diseases in South Korea Methods: Four hundreds and thirteen H. pylori colonies were analyzed [78 colonies from 47 controls

68 colonies from 37 benign gastric ulcer (BGU) patients

104 colonies from 55 duodenal ulcer (DU) patients

119 colonies from 75 stomach cancer (SC) patients

44 colonies from 35 dysplasia patients]. PCR amplifications for vacA, cagA, iceA, oipA and dupA were performed using DNA extract from H. pylori isolates cultured from mucosal biopsy specimens. Results: Most colonies were composed of vacA s1 (100.0%), i1 (98.3%) and m1 (92.7%), cagA (85.9%), iceA1 (95.6%), oipA (89.5%) and dupA (90.3%) genotype. dupA was expressed more frequent in BGU (98.4%), DU (99.0%) and SC (97.6%) than control (68.8%) (p<.001). Infection by H. pylori with dupA showed an increased risk of BGU (OR 4.43, 95% CI 4.17-284.33), DU (OR 36.99, 95% CI 4.56-300.10) and SC (OR 16.28, 95% CI 3.44-77.02). Conclusion: H. pylori infection in South Korea appeared to be closely related to highly virulent strains [vacA s1/i1/m1, cagA(+), iceA1(+), oipA(+) and dupA(+)]. It was considered that dupA had intimate association with the development of peptic ulcer disease and stomach cancer.