Interleukin-6 polymorphisms, Helicobacter pylori infection in adult Brazilian patients with chronic gastritis and gastric adenocarcinoma.

Background: The discovery of Helicobacter pylori offered the etiologic agent of the initiating event of the inflammatory cascade. It has been confirmed that the development of gastric cancer spans over several decades sequentially starting with the acquisition of H. pylori infection and the development of chronic gastritis. The IL-6 gene (Il-6), inflammatory cytokine and the single-nucleotide polymorphisms (SNPs) at the 5' flanking region of the Il-6 gene promoter (G or C at -174 base and at -572 or -597 C or A) have been identified with increased Il-6 levels.
Methods: Biopsies were collected from 168 patients. SNPs in Il-6-174 were analyzed by PCR-RFLP.
Results: Promoter SNP of Il-6 at -174 base were within Hardy-Weinberg equilibrium. We did not find any association between the frequencies of -174 polymorphism with specific histological type of gastric adenocarcinoma, but the G (guanine) allele at -174 was significantly higher in gastric adenocarcinoma than in patients with chronic gastritis.
Conclusions: We observed an association between GG allele on -174 base with gastric cancer.