Toll样受体9基因启动子单核苷酸多态性与儿童变应性哮喘的相关性

Objective To investigate the distribution characteristics of the single nucleotide polymorphisms (SNPs) in the promoter region of the toll-like receptor 9 gene (TLR9)in Chinese Han children from Zhejiang province, and their associations with asthma susceptibility and phenotypes. Methods A case-control study was conducted. A total of 312 asthmatic children aged between 1.9 and 11.6 and 339 age matched healthy controls were enrolled in this study from April 2007 to November 2008. The -1486 C/T in rs187084 and -1237 C/T in rs5743836 loci of the TLR9 gene were genotyped by direct DNA sequencing of the PCR products. Serum levels of IFN-γ, IL-12 and IL-4 were detected by enzyme linked immunosorbent assay. Serum levels of total IgE were detected by chemiluminescence, and serum levels of ildren (P＜0.01). The CC genotype had the lowest levels of serum IFN-γand the highest levels of serum IL-4 among the three genotypes. There were no significant differences in these cytokines among the healthy controls (P＞0.05). No statistical differences of serum IL-12 were found among the three genotypes in the two groups (P＞0.05). (4) There were no significant differences of total IgE (log-transformed) among the three genotypes in the asthmatic children (P＞0. 05). Conclusion The -1237 C/T polymorphism of TLR9 gene was not detected in Chinese Han children in this study. The - 1486 C/T polymorphism was associated with the levels of serum IFN-γ and IL-4 in children with asthma.However, there were no correlations between the -1486C/T polymorphism and serum IL-12 levels, total IgE levels or asthmatic susceptibility.

Association of single nucleotide polymorphisms in the promoter region of the TLR9 gene with childhood atopic asthma