IL-18 gene polymorphisms were associated with risk of chronic obstructive pulmonary disease in a Chinese Han population

Abstract

Chronic obstructive pulmonary disease (COPD) is a kind of lung disease with high morbidity and mortality. Genetic polymorphisms of IL18 have been associated with respiratory system disease such as asthma, pulmonary tuberculosis, and lung cancer; however, little information is found about the association between IL18 polymorphisms and risk of COPD. We investigated the association between single nucleotide polymorphisms (SNPs) in IL18 and COPD risk in a case–control study that included 300 COPD cases and 300 healthy controls. Five SNPs were selected and genotyped using the Sequenom MassARRAY platform. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression after adjusting for gender and age. In the genotype model analysis, we determined that rs2043055 polymorphism had an increased effect on the risk of COPD (GG versus AA: OR = 5.29; 95% CI = 1.15–24.35; p = 0.006). In the genetic model analysis, we identified four SNPs associated with COPD risk under recessive model. The “GG” genotype of rs2043055 and rs187238 were associated with increased risk of COPD (rs2043055: OR = 5.13, 95% CI = 1.12-23.49, p = 0.021; rs187238: OR = 4.99, 95% CI = 1.08–23.06, p = 0.025). Additionally, the “CC” genotype of rs1946519 was associated with increased risk of COPD (OR = 2.31; 95% CI = 1.03–5.19; p = 0.038). By contrast, the “TT” genotype of rs1946518 was associated with decreased risk of COPD (OR = 0.58; 95% CI = 0.35–0.98; p = 0.039). Our data shed new light on the association between IL18 polymorphisms and risk of COPD in a Chinese Han population.