Gene locus polymorphisms and expression levels of interleukin-1 in lumbar disc disease: a meta-analysis and immunohistochemical study

Abstract

Abstract Background: To investigate the association between interleukin (IL)-1α (rs1800587), IL-1β (rs1143634) and IL-1 receptor antagonist (RN) variable number tandem repeat (VNTR) polymorphisms, expression levels and lumbar disc disease (LDD).Methods: All relevant articles were searched from 4 databases including PubMed, Embase, Web of Science and China National Knowledge Infrastructure (CNKI). Odds ratios (OR) with 95 % confidence intervals (CI) were calculated to evaluate the association between IL-1 gene locus polymorphisms (rs1800587 in IL-1α, rs1143634 in IL-1β, VNTR in IL-1RN) and LDD susceptibility. Statistical analysis was conducted by Review Manager (Revman) 5.31 software. Furthermore, qRT-PCR and immunohistochemistry (IHC) were performed to evaluate IL-1α, IL-1β and IL-1RN expressions in the normal and degenerated disc.Results: A total of 15 case-control studies (1455 cases and 2362 controls) were included in our meta-analysis. The pooled results suggested that IL-1α rs1800587 polymorphism was associated with an increased risk of LDD in overall population (T vs. C, OR=1.21, 95%CI=1.04-1.40, P=0.01). The subgroup analysis found a significant association between IL-1β rs1143634 polymorphism and LDD in Asian population (T vs. C, OR=0.61, 95%CI=0.39-0.96, P=0.03). Results of qRT-PCR and IHC demonstrated that expressions of IL-1α and IL-1-β were significantly increased in the degenerated disc. (all P<0.05 )Conclusion: IL-1α rs1800587 and IL-1β rs1143634 polymorphisms were significantly associated with LDD in overall population and in Asian population, respectively.