Relevance of VacA and mucosal pathological changes in Chinese patients with upper gastrointestinal diseases before and after Helicobacter pylori eradication

Objective: To investigate the influence of VacA activity on gastric mucosa prior to and after Helicobacter pylori eradication in Chinese patients with peptic ulcers and chronic gastritis. Methods: Seventy-four dyspeptic patients with H. pylori infection were enrolled. The status of H. pylori infection was evaluated by culture and histopathology before and 4-6 weeks after H. pylori eradication therapy. Histological specimens were examined and graded semiquantitatively according to the updated Sydney classification. Results: Helicobacter pylori with VacA was found in 59 of 74 patients (80%), and its prevalence in patients with peptic ulcers and chronic gastritis was similar. Helicobacter pylori eradication rates in patients with VacA⁺ and VacA^- strains were similar. Before eradication, the degrees of acute or chronic inflammation, epithelial damage, atrophy, intestinal metaplasia (IM) and the number of lymphoid follicles were similar in patients with VacA⁺ and VacA^- H. pylori. Four to 6 weeks after the eradication of H. pylori infection, the degrees of acute and chronic inflammation, and epithelial damage in the antrum decreased significantly, particularly in patients with VacA⁺ H. pylori (P < 0.0001). The number of lymphoid follicles in the antrum also decreased more in patients with VacA⁺ H. pylori than in those with VacA^- H. pylori (P = 0.051). However, there was no difference in the extent of atrophy and IM between these two groups. Conclusions: There is no specific correlation between VacA⁺/VacA^- H. pylori strains and mucosal clinicopathological features in Chines patients with upper gastrointestinal diseases before and after eradication therapy. Successful eradication of H. pylori infection does not improve atrophic and IM lesions of the gastric mucosa.