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

Background/Aims: To investigate the influence of VacA activity on the gastric mucosa prior to and after Helicobacter pylori (H. pylori) eradication in Chinese patients with peptic ulcer disease and chronic gastritis. Methods: Seventy-four consecutive dyspeptic Chinese 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. Histologic specimens were examined and graded semiquantitatively according to the updated Sydney classification. Results: VacA⁺ H. pylori organisms were isolated from 59/74 (80%) patients, its prevalence in peptic ulcer disease and chronic gastritis was similar, and the eradication rates were also similar in those with VacA⁺ and VacA^- H. pylori strains. 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-six weeks after eradication of H. pylori infection, the degrees of acute and chronic inflammation and epithelial damage in the antrum decreased significantly, particularly in those with VacA⁺ H. pylori (P < 0.000 1), whereas the number of lymphoid follicles in the antrum also diminished more in those with VacA⁺ H. pylori (P = 0.051). However, the degrees of atrophy and IM remained unchanged. Conclusions: There is no specific correlation between VacA⁺ and VacA^- H. pylori strains and mucosal clinicopathological features among Chinese patients with upper gastrointestinal diseases before and after eradication therapy. Successful eradication of H. pylori infection dose not improve the atrophic and IM lesions of gastric mucosa.