Predicting the role of dupA-positive Helicobacter pylori strains in severe gastrointestinal disorders: An updated meta-analysis

Abstract

BackgroundIn 2005, a novel virulence factor of Helicobacter pylori was discovered that could increase the risk of duodenal ulceration by stimulating the secretion of IL-8. Hence, it was named duodenal ulcer promoting gene A (dupA). According to statistical analysis, the association between dupA and severe clinical outcomes in Asian and Western countries was evaluate. MethodsA systematic search was performed on the association between dupA and its clinical outcomes. Finally, a sensitivity analysis was used to eliminate the significant heterogeneity, as well as random-effect meta-regression was used to assess confounding variables such as cagA and vacA s1. Finally, publication bias was calculated using Egger's and Begg's p value tests. ResultsOf 182 related studies, 31 reliable studies were included in the quantitative analysis according to inclusion criteria. Sensitivity analysis showed that dupA significantly increases the risk of duodenal ulcer and gastric cancer (OR: 1.58; 95% CI: 1.33–1.88 and OR: 1.27; 95% Cl: 0.99–1.63, respectively), while no significant relationship was observed between dupA and gastric ulcer risk (OR: 1.27; 95% Cl: 0.99–1.63). Based on meta-regression results, cagA and vacA s1 (slope: 0.31; p value: 0.05, slope: 0.23; p value: 0.05, respectively) virulence factors could significantly effect on the association between dupA and the risk of gastric cancer. Due to confounding effects of cagA and vacA s1, the virulence effects of dupA are distorted, and it appears that this gene alone does not increase the risk of gastric cancer. ConclusionOur results confirmed the previous studies, and we found that dupA alone does not appear to increase the risk of gastric adenocarcinoma.