Background & objectives: Several studies have described VacA and CagA as the two important virulence determinants of Helicobacter pylori, which are associated with gastric ulcer (GU) and duodenal ulcer (DU). The aim of present study was to determine the associations of the i and d regions genotypes of H. pylori vacA gene and cagA status with GU and DU risk.

Methods: A total of 177 isolates were cultured from the biopsies of Iranian patients with different geographic origins and genotyped. Data were collected and analyzed.

Results: Frequency of the vacA i1, i2, i1i2, d1, and d2 alleles and cagA in all patients was 42.9%, 55.4%, 1.7%, 41.8%, 58.2% and 68.4%, respectively. There was a significant difference between the frequencies of vacA i1 in isolates from GU than those from non-atrophic gastritis (p<0.05). When the GU was considered as a dependant factor by the multiple logistic regression analysis, the vacA i1 genotype was significantly associated with the age- and sex-adjusted risk for GU (p=0.006, odds ratio [OR]=3.56 95% confidence interval [CI]=1.45–8.75). Statistical analysis showed no significant association between vacA d genotype and digestive diseases. After controlling for age and sex variables, the cagA genotype remained in the final model when the DU was considered as a dependant factor by the the multiple logistic regression analysis (p=0.021, OR=3.77 95% CI=1.22-11.60).

Conclusion: We have proposed that the H. pylori vacA i1 and cagA genotypes could be considered as benefit biomarkers for prediction of risk of GU and DU in Iran, respectively.