Association of Interleukin (IL)-12 and IL-27 Gene Polymorphisms with Chronic Obstructive Pulmonary Disease in a Chinese Population

The pathogenesis of chronic obstructive pulmonary disease (COPD) is not fully understood, and environment and genetic factors have been investigated. Moreover, cytokine genes play an important role in COPD pathogenesis. However, the molecular mechanism of COPD induced by the factors is still unknown. The present study was undertaken to clarify a role of interleukin (IL)-12 16974A/C and IL-27 4730T/C, -964A/G, and 2905T/G polymorphisms in Chinese subjects with COPD. Polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) and sequence analyses were used to type IL-12 and IL-27 polymorphisms in 120 patients with COPD and 100 healthy controls. There were significant differences in the genotype and allele distribution of -964A/G and 2905T/G polymorphisms of the IL-27 gene among cases and controls in a Chinese population. When compared with the control group, subjects with AG genotype of the IL-27 -964A/G had a 2.22-fold decreased risk of COPD (odds ratio [OR] = 0.450, 95% confidence interval [CI]: 0.245-0.826; p = 0.009), and subjects with TG genotype of the IL-27 2905T/G had a 2.85-fold decreased risk of COPD (OR = 0.351, 95% CI: 0.137-0.899; p = 0.024). Compared with the TAT haplotype, the TGG haplotype was associated with a significantly decreased risk of COPD (OR = 0.29, 95% CI: 0.108-0.784; p = 0.010). Even after Bonferroni corrections, significant associations with COPD were observed for the AG genotype of the IL-27 -964A/G and the TGG haplotype of the IL-27 gene. Our data suggest that polymorphisms in the IL-27 gene may play a role in the development of COPD in Chinese population.