Meta-analysis of the association of IL1-RN variable number of tandem repeats polymorphism with osteoarthritis risk

OBJECTIVE: The aim of this meta-analysis was to clarify the role of Interleukin-1 receptor antagonist gene (IL1-RN) Variable Number of Tandem Repeats (VNTR) polymorphism on the risk of OA by means of meta-analysis. METHODS: Eligible articles were retrieved from PubMed, Web of science and Google scholar with a total of 1187 OA cases and 2659 controls. The strength of the association between the IL1-RN VNTR polymorphism and the risk of OA was assessed by odds ratios (ORs) with the corresponding 95% confidence interval (CI) for each study. RESULTS: The meta-analysis of seven published studies retrieved from the literature search showed a significantly increased OA risk in the recessive model analysis (22 vs 2L + LL: P(b) = 0.18, I(2) = 32.8, OR(95% CI) = 1.50(1.12, 2.02), P = 0.007), the additive model analysis (22 vs LL: P(b) = 0.08, I(2) = 46.8, OR(95% CI) = 1.56(1.15, 2.12), P = 0.004) and in the allele contrast model (2 vs L: P(b) = 0.02, I(2) = 58.8, OR(95% CI) = 1.20(1.05, 1.36), P = 0.007). By subgroup analysis, the IL1-RN VNTR polymorphism was found to be significantly associated with OA susceptibility in Caucasian and Hospital based case-control study (HCC) groups. CONCLUSION: This meta-analysis showed that IL1-RN VNTR polymorphism may increase the susceptibility to OA. More studies with detailed information are needed to validate our conclusion. LEVEL OF EVIDENCE: Level III, diagnostic study.