Interleukin-8 -251A/T polymorphism and periodontitis susceptibility: a meta-analysis

The -251A/T polymorphism in the anti-inflammatory cytokine interleukin-8 (IL-8) gene has been implicated in susceptibility to periodontitis; however, this correlation has not been elucidated. In this meta-analysis, we investigated the association between the IL-8 -251A/T polymorphism and the risk of periodontitis. All eligible case-control studies published until August 2014 were identified and extracted from PubMed, Web of Science, EMBASE, China National Knowledge Internet, and WanFang databases. The strength of this association was accessed by pooled odds ratios (ORs) with 95% confidence intervals (CIs), using either a fixed- or random-effect model. Nine case-control studies, including 1811 cases and 2043 controls, were identified. Overall, no significant associations were found between the IL-8 -251A/T polymorphism and the risk of periodontitis. The results of the analysis of periodontitis subgroup revealed similarities between chronic periodontitis and aggressive periodontitis. An additional analysis based on ethnicity revealed an association between the IL-8 -251A/T polymorphism and periodontitis among Asians (dominant model, OR = 1.784, 95%CI = 1.130-2.817) and a mixed population (AA vs TT, OR = 0.667, 95%CI = 0.471-0.974). The results of this meta-analysis suggest that the IL-8 -251A/T polymorphism may increase the risk of periodontitis in Asian and mixed populations. However, larger and well-designed studies are warranted to validate our findings.