Associations between the Plasticity Region Genes of Helicobacter pylori and Gastroduodenal Diseases in a High-Prevalence Area

Abstract

Background/aims: Genes associated with the Helicobacter pylori (H. pylori) plasticity region may play a role in the pathogenesis of H. pylori. We compared the genes jhp0940, jhp0947, and jhp0986 in H. pylori isolates from patients with different gastroduodenal diseases and in different age groups.

Methods: The H. pylori hyperplasticity region genes jhp0940, jhp0947, and jhp0986 were studied by PCR. We also evaluated whether these genes were related to the cytotoxin-associated gene (cagA) and histology findings.

Results: Of the patient cohort, 71 (62%) were positive for jhp0940, 67 (59%) for jhp0947, 12 (10%) for jhp0986, and 69 (60%) for cagA. jhp0940 (n=18, 67%) and jhp0947 (n=23, 85%) were found more frequently in duodenal ulcer (DU) patients than in gastritis patients (n=14, 39%; p=0.029 and p<0.001, respectively). Gastric ulcer (GU) was more frequently associated with jhp0940 (17 patients, 77%; p=0.003) than with gastritis (14 patients, 39%). Gastric carcinoma (GC) was more strongly associated with both jhp0940 (22 patients, 76%; p=0.003) and jhp0947 (22 patients, 76%; p=0.003) than was gastritis (14 patients, 39%). jhp0947 was more frequently associated with chronic active inflammation (58 patients, 87%; p=0.009) than with chronic inflammation (9 patients, 13%). Multivariate analysis demonstrated that jhp0947 was associated with DU (odds ratio, 6.1; 95% confidence interval, 1.87-20).

Conclusions: The genes jhp0947 and jhp0940 were identified in H. pylori isolates from patients with GC and DU, while jhp0940 was also isolated from patients with GU. jhp0947 was independently associated with DU.

Keywords: Duodenal ulcer; Gastric carcinoma; Gastric ulcer; Helicobacter pylori; Hyperplasticity region.