Association of myeloperoxidase -463 G/A polymorphism with clinical outcome of Helicobacter pylori infection in Iranian patients with gastrointestinal diseases.

BACKGROUND Polymorphisms in the immune related genes are important in the clinical outcome of Helicobacter pylori infection. Myeloperoxidase -463 G/A polymorphism has been shown to reduce enzyme expression and activity. OBJECTIVE the aim of the present study is to investigate the association of myeloperoxidase G-463A polymorphism with clinical outcome of Helicobacter pylori infection. METHODS two hundred and eighty five patients with positive culture of Helicobacter pylori from their gastric biopsies are included in this study. Human leukocyte DNA was extracted using salting out method and myeloperoxidase G-463A polymorphism was investigated by PCR-RFLP. All clinicopathological data were collected from individual records. RESULTS When the patients were categorized according to the high (GG) and low + intermediate (AG+AA) genotypes of myeloperoxidase producers, there was a significant association between myeloperoxidase G-463A genotypes and clinical outcome of Helicobacter pylori infection (p=0.006). In search for combined effect of cagA status and myeloperoxidase genotypes on clinical presentations, only in cagA- Helicobacter pylori infected patients a significant association between myeloperoxidase genotypes and clinical outcome was found (p=0.0001). Also this association was found only in patients infected with vacA s1m1 genotype (p=0.008). CONCLUSIONS Our findings suggest that the myeloperoxidase G-463A polymorphism is a host genetic factor which determines the clinical outcome of Helicobacter pylori infection. Moreover, the combination of host and bacterial genetics could provide a better understanding of clinical outcome after infection with Helicobacter pylori.