贵阳地区250例哮喘患儿IL-4基因-590C/T的多态性与血浆IgE水平的相关性

Correlation between Polymorphism of -590C/T in IL-4 Gene Promoter and Plasma Ig E Levels in Asthma Children

目的：探讨白细胞介素-4（IL-4）基因启动子区-590C/T位点与贵阳地区儿童支气管哮喘的相关性及不同基因型对患儿血浆总Ig E（TIg E）水平的影响。方法：用聚合酶链式反应-限制性片段长度多态性（PCRRFLP）方法,检测贵阳地区250例哮喘患儿（哮喘组）及200例健康对照儿童（对照组）IL-4基因-590C/T位点的多态性,分析IL-4基因-590C/T位点基因型频率分布,以及与哮喘危险性的关系;采用酶联免疫吸附法（ELISA）检测两组血浆TIg E水平,比较l L-4-590C/T位点不同基因型间血浆TIg E水平。结果：IL-4基因-590C/T位点在哮喘组和对照组中存在CC、CT、TT 3种基因型,且基因型频率在组间的分布差异有统计学意义（χ2=13.395,P〈0.01）;哮喘组和对照组IL-4基因-590C/T位点C等位基因频率与T等位基因频率的差异有统计学意义（χ2=16.384,P〈0.01）,此位点变异基因型TT携带者患病危险性均高于CC纯合子或CT杂合子基因型携带者（OR=1.78,95%CI=1.22~2.60）,且T变异等位基因携带者患病危险均高于非携带者（χ2=9.851,P〈0.01;OR=1.82,95%CI=1.36~2.44）;相同基因型血浆TIg E水平哮喘组高于对照组（P〈0.05）,哮喘组变异基因T携带者TIg E水平明显高于非携带者（t=1.978,P〈0.05）,对照组变异基因T携带者与非携带者TIg E水平比较,差异无统计学意义（t=0.249,P〉0.05）。结论：IL-4基因-590C/T位点T等位基因与哮喘发病相关,且变异基因T与血浆TIg E水平升高相关。

Objective： To investigate the correlation between the single nucleotide polymorphisms （SNP） of -590C/T in the promoter region of IL-4 gene and asthma children in Guiyang, and to study the impact of this polymorphism on total plasma IgE （TIgE） levels. Methods ： Polymerase chain reac- tion-restriction fragment length polymorphism（PCR-RFLP） was used to detect -590C/T polymorphism of 250 children with asthma in Guiyang and 200 healthy children. The TIgE levels were determined by enzyme-linked immunosorbent assay （ELISA）. The TIgE levels were compared among children with different -590C/T genotypes. Results： There were three genotypes in -590C locus of IL-4 gene： CC, CT and TT, significant differences were found in genotypic frequency between the two groups （X2 = 13. 395 ,P 〈0.01）. The C allele frequencies and the T allele frequencies had significant differences between the two groups（x2 = 16. 384, P 〈0.01 ）. Compared with CC and CT genotypes in this locus,the risk of developing asthma of Tr carrier was significantly higher （ OR = 1.78, 95% CI = 1. 22 ~ 2.60）, and mutant T allele increased the risk of developing asthma（x2 = 9. 851, P 〈 0. 01; OR = 1.82,95 % CI = 1.36 - 2.44）. With the same genotype and locus, the TIgE levels of asthma children were higher than those of control （ P 〈 0.05 ）, and there were significant differences in TIgE levels be- tween subjects with or without mutant T allele in asthma group （ t = 1. 978, P 〈 0.05 ）, but there was no significant difference in TIgE levels between subjects with or without mutant T allele in control group （ t = 0. 249, P 〉 0.05 ）. Conclusions： T allele in -590C locus of IL-4 gene is associated with asthma, and mutant T allele is correlated with increasing of TIgE levels.