relationship of il1 and tnf polymorphisms with helicobacter pylori in gastric diseases in a brazilian population it is well known that the risk of development of gastric cancer gc in helicobacter pyloriinfected patients depends on several factors thus the aim of this study was to investigate the effect of proinflammatory cytokine gene polymorphisms for il1 il1rn and tnf on the development of gc in a brazilian population a total of 202 biopsies obtained from brazilian patients with chronic gastritis and gc were included in the study infection with h pylori caga was determined by the polymerase chain reaction pcr as previously described il1 il1rn and tnf polymorphism genotyping was performed by restriction fragment length polymorphism pcr associations between gene polymorphisms clinical diseases and virulence markers were evaluated using either the test or the fisher exact test our results demonstrated that the il1 511 cc and il1 511 ct alleles were associated with chronic gastritis in h pyloripositive patients p 004 and p 005 respectively and the il1 511 cc genotype was associated with gc p 003 the frequency of il1rn alleles from patients with chronic gastritis and gc indicated that there was no difference between the genotypes of the groups studied similar results were found for tnf 308 gene polymorphisms our results indicate that the il1 511 cc and ct gene polymorphisms are associated with chronic gastritis and gc development in h pyloriinfected individuals