Background: Helicobacter pylori induces inflammation of gastric mucosa regulated by several interleukins. This study examined associations between anti-Helicobacter pylori immunoglobulin G antibody seropositivity and functional polymorphisms of interleukin-8 T-251 A and interleukin-10 T-819C.
Materials and methods: The subjects were 454 health check-up examinees (126 males and 328 females) without a history of cancer, aged 35-85 years, residing in Nagoya, Japan. After written informed consent was obtained individually, residual blood was anonymously applied for anti-Helicobacter pylori immunoglobulin G antibody testing and genotyping by the polymerase chain reaction with confronting two-pair primers.
Results: The genotype frequency of interleukin-8 T-251 A was 52.2% for TT, 39.5% for TA, and 8.3% for AA, and that of interleukin-10 T-819C was 49.5% for TT, 39.9% for TC and 10.6% for CC. Although the differences in the positive rates among the genotypes were not marked, 115 individuals with interleukin-8-251TT (low expression genotype) and interleukin-10-819TT (high expression genotype) had a higher rate (63.5%) than the others (52.0%). Relative to the combination of interleukin-8-251TT and interleukin-10-819TT, the sex-age-adjusted odds ratio for those with the other combinations was 0.62 (95% confidence interval, 0.39-0.98). The adjusted odds ratio among 65 current smokers was 0.13 (0.03-0.61).
Conclusions: The observed association suggests that individuals with interleukin-8-251TT and interleukin-10-819TT, a combination presumably causing mild inflammation, have a higher probability of the continuing Helicobacter pylori infection, especially among current smokers.