Association of the $myeloperoxidase^{-463}$ G $\rightarrow$ A polymorphism with development of atrophy in Helicobacter pylori-infected gastritis

Background : Helicobacter pylori (H. pylori) infection is characterized by extensive infiltration of neutrophile and induces atrophic gastritis, however, the host factors governing the development of atrophy have not been defined. Myeloperoxidase (MPO) in neutrophils amplifies the oxidative potential, thus MPO is suspected to play a role in H. pylori-induced gastric atrophy. Therefore, we explored the association of host MPO genetic polymorphism with atrophic gastritis upon H. pylori infection. Methods : Biopsy specimens taken from the gastric mucosa were examined histologically in 127 patients. The PCR-RFLP assay was used to characterize MPO genotypes. Results : The distributions of MPO genotypes were MPO (G/G) 81.9% and MPO (G/A) 18.1%. None of MPO (A/A) genotype was observed in 127 patients studied. The degree of active inflammation increased with the increase in H. pylori colonization. A strong positive correlation between the levels of neutrophil infiltration and gastric atrophy was found only in MPO (G/G) but not in MPO (G/A) genotype. Conclusion : MPO G/G genotype may be a critical determinant in the pathogenesis of atrophic gastritis subsequent to H. pylori infection.