Association of Cytokine Gene Polymorphisms with Gastritis in a Kazakh Population

Background: Gastritis and gastric cancer are the most common diseases in the Kazakh population. Polymorphisms in genes coding of cytokines have been played important role with gastric disease risk. The risk alleles of cytokines in patients with gastritis can predict the risk of developing gastric cancer. The aim of this study was to investigate cytokine gene polymorphisms as risk factors for the development of gastritis in a case-control study with gastritis patients and healthy individuals from the Kazakh ethnic group, living in North Kazakhstan. Materials and Methods: The polymerase chain reaction followed by direct sequencing were used for detection of two functional polymorphisms in the IL1 gene family, and TaqMan SNP Genotyping Assay Sets were applied for three potentially functional polymorphisms in the IL10 gene, and one in the TNFA promoter. Results: Association analysis of studied allelic variants and the development of gastritis in H. pylori-positive patients showed that IL1B -31C/C, IL1B -511T/T and IL1RN -2/2 allelic variants were associated with development of gastritis (OR=1.8 (1.07-3.16), p=0.025; OR=1.7 (1.04-2.99), p=0.035, and OR=4.92 (2.45-9.85), p<0.001) respectively. Haplotype C-T that combines both homozygous allelic variants of IL1B gene also had a statistically significant association with slightly higher OR (OR: 1.43, 95% CI: 1.08-1.88). Conclusions: The data from the current study showed that the genotype IL-1B -511T/-31C-IL1-RN-2 and H. pylori infection increase risk of gastritis in the Kazakh population. That genotype combination might be a factor increasing the risk of developing gastric cancer.