Aim: To elucidate the relations between the myeloperoxidase (-468)G-->A polymorphism and the development of duodenal ulcer (DU), and to investigate the impacts of this host genetic polymorphism on the histopathological features of Helicobacter pylori (H pylori)-related gastritis.
Methods: In a case-control study of 115 consecutive DU patients and 182 controls, the myeloperoxidase (-468)G-->A polymorphism was genotyped. Additionally, gastric mucosal changes were examined according to the updated Sydney System.
Results: The two study groups differed in the distributions of myeloperoxidase genotypes (P = 0.008). All six individuals carrying myeloperoxidase A/A genotypes were in the DU group. The carriage of myeloperoxidase allele A and H pylori infection were associated with an increased risk of DU with odds ratios (OR) of 2.3 and 5.8, respectively. The combined risk of the carriage of myeloperoxidase allele A and H pylori infection for DU was 8.7 (95% CI, 3.5-21.8). In the H pylori-infected individuals, allele A carriers displayed higher bacterial density scores (P = 0.04) in the antrum than did non-carriers.
Conclusion: This work verifies for the first time the association of myeloperoxidase (-468)G-->A polymorphism with antral H pylori density and DU disease. The mechanisms underlying this genetic polymorphism in developing DU disease merit further investigations.