Presence of the Genes <i>cag</i>A, <i>cag</i>E, <i>vir</i>B11 and Allelic Variation of <i>vac</i>A of <i>Helicobacter pylori</i> Are Associated with the Activity of Gastritis

Abstract

Non-atrophic active chronic gastritis (ACG) is characterized by the presence of H. pylori in the gastric epithelium, known to be one of the first steps that precede progression to gastric adenocarcinoma. Inactive chronic gastritis ( ICG) suggests that the patient has H. pylori gastritis, but this diagnosis is rarely made in routine histopathology. C linical manifestations associated with H. pylori infection are potentially due to differences in virulence between strains; however, it is unclear if the progression of ACG to ICG depends on the H. pylori strain. The aim of this study was to compare the prevalence of the virulence factors of H. pylori found in patients with ACG and ICG, and its influence on the development of ICG. A significant association was observed between H. pylori detection by histological examination and the activity of gastritis (p < 0.01). Long-term use of proton pump inhibitors (PPI) (>1 year) was reported by 28.6% of the ACG group and 42.5% of the ICG, while no evidence of association between long-term use of PPI and decreased inflammation was found in the patients studied. The genes cag A, cag E and vir B11 were statistically associated with ACG (p = 0.01, p < 0.001 and p = 0.002, respectively). In the vac As1 allele groups, ACG was associated with the most virulent group (p = 0.0015), while ICG was associated with the less virulent group (p < 0.001). The rate of co-infection was significantly higher in ICG than in ACG cases (p = 0.02). In conclusion, this study points to the role of virulent strains of H. pylori in the non-resolution of gastritis.