Recurrence of Helicobacter pylori following successful eradication and clinical outcomes in Korean patients.

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) infections can recur as either recrudescence or reinfection. At a time when the decline in the eradication rate is becoming evident, increases in the rate of recurrence are concerning. In addition, there are no guidelines for selecting an eradication regimen for H. pylori recurrence. MATERIALS AND METHODS: A total of 996 H. pylori-infected patients treated with proton-pump inhibitor-based triple eradication therapy between 2017 and 2022 were enrolled in the study, and successful eradication therapies were confirmed by the 13 C-urea breath test. When retested within 1 year after successful eradication, analysis related to recrudescence was performed, and when retested after 1 year, analysis related to reinfection was performed. We reviewed the medical records and treatment outcomes of patients with H. pylori reinfection after successful eradication. RESULTS: The recrudescence rate was 3.9% (9/228), and the reinfection rate was 3.7% (36/970 person-year). The frequency of reinfection reached 5.9% per person-year within the first 24 months and 2.0%-2.4% per person-year thereafter. In multivariate factor analysis, reinfection was significantly higher in patients with non-ulcer dyspepsia (p < 0.01). At first-line therapy for reinfection, the eradication rate of standard triple therapy (STT) was 50.0% (16/32). The eradication rate of second-line bismuth quadruple therapy was 81.3% (13/16), and levofloxacin-based rescue therapy was 66.7% (2/3). CONCLUSION: Re-treatment of patients with H. pylori reinfection with STT had limited efficacy. Prospective research is needed to determine whether patients with non-ulcer dyspepsia are vulnerable to reinfection.

Helicobacter pylori-associated Chronic Atrophic Gastritis and Progression of Gastric Carcinogenesis.

Chronic inflammation due to a Helicobacter pylori (H. pylori) infection is a representative cause of gastric cancer that can promote gastric carcinogenesis by abnormally activating immune cells and increasing the inflammatory cytokines levels. H. pylori infections directly cause DNA double-strand breaks in gastric epithelial cells and genetic damage by increasing the enzymatic activity of cytidine deaminase. Eventually, gastric cancer is induced through dysplasia. Hypermethylation of tumor suppressor genes is an important cause of gastric cancer because of a H. pylori infection. In addition, the changes in gastric microbiota and the mucosal inflammatory changes associated with a co-infection with the Epstein-Barr virus are associated with gastric cancer development. DNA damage induced by H. pylori and the subsequent responses of gastric stem cells have implications for gastric carcinogenesis. Although the pathogenesis of H. pylori has been established, many uncertainties remain, requiring more study.