[Association between -590C/T polymorphisms of interleukin-4 gene and chronic periodontitis: a meta-analysis]

To evaluate the relationship between -590C/T polymorphisms of interleukin-4 gene and chronic periodontitis using meta-analysis.

The selected studies were pooled from eight major electronic databases for case-control study. To gain a more precise estimation of the relationship, a stratified meta-analysis with two subgroups was performed according to the races. Heterogeneity, publication bias and sensitivity analysis were also explored.

Totally 8 studies were recruited. Total sample sizes for chronic periodontitis and control groups were 628 and 717, respectively. Meta-analysis showed that both -590C/T polymorphisms and allele frequency were not significantly associated with chronic periodontitis. In subgroup analysis, a significant association of increased chronic periodontitis risk and T allele was found. The results also indicated a significant correlation between -590C/T polymorphisms of IL-4 and Caucasian who suffered from chronic periodontitis(C vs.T: OR=0.71,95% CI=0.56-0.89;CC vs.CT:OR=0.60,95% CI=0.38-0.94;recessive genetic model CC vs.CT+TT:OR=0.61,95% CI=0.42-0.88), further analysis of the results showed the CC genotype was about 39% less likely to have chronic periodontitis than the CT and TT genotype in Caucasian individuals.However, these significant associations was not found in Asian group.

The meta-analysis suggests there may be an important effect of single nucleotide polymorphisms (SNPs) in the promoter region of IL-4 gene on the pathogenesis of chronic periodontitis in Caucasian. This warrants further investigation in larger studies and multi-race epidemiological to evaluate the results.