Helicobacter pylori vacA allelic combination, dupA, cagE and cagA genotypes and their associations with gastric diseases among Moroccan population.

Abstract

The combination of the four regions of vacA with cagA, cagE, dupA genes and cagA-EPIYA motifs, was studied to find the most likely combination that can be used as a disease determinant marker in Moroccan population. A total of 838 H. pylori positive obtained from consenting patients, that were previously analyzed by PCR to characterize vacA-s -m, -i regions, cagE status and cagA 3' region polymorphism, were used to characterize vacA-d region and to determine dupA gene status. The analysis shows the predominance of the less virulent combination (vacA(s2m2i2d2)dupA(-)cagE(-)cagA(-)), and shows that the risk of gastric cancer is 13.33 fold higher (1.06-166.37)) in patients infected by strains harboring vacA(s1m1i1d1)dupA(-)cagE(+)cagA(2EPIYA-C) compared to patients with gastritis without lesions and infected by H.pylori strains harboring vacA(s2m2i2d2)dupA(-)cagE(-)cagA(-). The infection with strains harboring vacA(s1m1i1d1)dupA(+)cagE(+)cagA(1EPIYAC) genotype combination represents a risk factor for gastric ulcer and duodenal ulcer (the Odds Ratio (95% CI) were 16 (1.09-234.24) and 6.54 (1.60-26.69) respectively) compared to patients with gastritis without lesions. These results suggest that the combination of the active form of vacA genotypes, dupA gene status and the number of EPIYA-C motif may be considered helpful markers to discriminate between several gastric diseases.