Relationship of Helicobacter pylori CagA and VacA status to morphological changes of gastric mucosa and primary clarithromycin resistance rate in patients with chronic gastritis: a cross-sectional study

Abstract

The aim: To investigate the relation of H. pylori CagA and VacA status to morphological changes of gastric mucosa and primary clarithromycin resistance rate in patients with chronic gastritis. Materials and methods: A cross-sectional study was conducted between May 2021 and January 2023, involving 64 patients with H. pylori-associated chronic gastritis. The patients were assigned to two groups according to the H. pylori virulence factors (CagA and VacA) status. The grades of inflammation, activity, atrophy, and metaplasia were determined according to the Houston-updated Sydney system. The identification of H. pylori genetic markers of antibiotic resistance and pathogenicity was performed by the polymerase chain reaction using paraffin stomach biopsies. Results: Patients with CagA- and VacA-positive H. pylori strains had significantly higher grades of inflammation both in the antrum and in the corpus of the stomach, activity of gastritis in the antrum, higher incidence and grade of atrophy in the antrum. Primary resistance to clarithromycin was significantly more prevalent in patients with CagA- and VacA-negative H. pylori strains (58.3% vs. 11.5%, p=0.002). Conclusions: Positive CagA and VacA status is related to more severe histopathological changes of gastric mucosa. In contrast, the rate of primary clarithromycin resistance is higher in patients CagA- and VacA-negative H. pylori strains.