IL1R1 gene polymorphisms are associated with knee osteoarthritis risk in the Chinese Han population

IL1R1, encoding interleukin 1 receptor type 1, is located in the IL-1 gene cluster and is involved in the pathogenesis of hand, hip, and knee osteoarthritis (OA) in different ethnicities. However, the link between IL1R1 polymorphisms and OA risk in the Chinese Han population is unknown. We studied the association between five IL1R1 polymorphisms (rs10490571, rs12712127, rs956730, rs3917225, and rs3917318) and OA risk by analyzing the genotypes of 298 knee OA patients and 297 controls using Sequenom MassARRAY technology. Logistic regression analysis after adjusting for gender and age revealed significant differences in the allele frequencies of IL1R1 rs956730 and IL1R1 rs3917225 between patients and controls. In addition, IL1R1 rs3917225 was associated with increased risk of knee OA with or without adjustment by age and gender in the dominant model (adjusted OR=1.47, 95% CI: 1.04-2.07, P=0.030), the recessive model (adjusted OR=1.75, 95% CI: 1.08-2.85, P=0.023), and the additive model (adjusted OR=1.40, 95% CI: 1.09-1.79, P=0.007). This study is the first to report that IL1R1 polymorphisms are associated with knee OA susceptibility in the Northwestern Chinese Han population.