白细胞介素4和10基因多态性与儿童哮喘的相关性及对细胞因子表达的影响

目的　探讨白细胞介素 (IL) 4和IL 10基因启动子区多态性与我国儿童哮喘的易感性和临床表型的关系 ,以及对细胞因子产生的调节作用。方法　用聚合酶链反应和限制性长度片段多态性 (PCR/RFLP)方法检测IL 4和IL 10基因启动子区 4个多态性位点 ,对 16 8例哮喘患儿及 5 3名正常对照儿童进行相关性分析 ,选择了各位点为纯合型的哮喘患儿 33例进行体外外周血单核细胞(PBMC)培养 ,用酶联免疫吸附 (ELISA)方法测定上清中的IL 4和IL 10含量。结果　 (1)我国儿童IL 4基因 5 89(C/T)位点等位基因频率与白种人和美国黑人之间明显不同 (P =0 0 0 1) ;IL 10基因 10 82(G/A)、 819(C/T)、 5 92 (A/C) 3个位点等位基因频率与英国人明显不同 (P =0 0 0 1)。 (2 )协方差分析显示 :IL 10基因 10 82 (G/A)、 819(C/T)影响哮喘患儿血清总IgE水平 ,进一步分析显示 10 82A和 819T等位基因与患儿高血清总IgE相关 (P <0 0 1,OR =3 16 ;P <0 0 5 ,OR =1 84 )。 (3)IL 10基因 819TT和ATA/ATA纯合型患儿的PBMC经刺激后 ,培养上清中IL 10含量升高程度明显低于其他型(P值均 <0 0 5 )。 (4)未获得IL 4基因启动子区 5 89(C/T)位点与哮喘表型有意义的结果 ,哮喘患儿PBMC经刺激后 ,上清中IL 4含量升高程度在 2种纯合型间差异无显

Correlation between polymorphism of IL-4 and IL-10 gene promoter and childhood asthma and their impact upon cytokine expression

OBJECTIVE: To investigate the correlation between the polymorphism of IL-4 and IL-10 gene promoters and the susceptibility of Chinese children to asthma and to study the impact of such polymorphism upon cytokine production. METHODS: The data of medical history, pulmonary function, hypersensitive test, and serum IgE were recorded among 168 unrelated Chinese children with asthma aged 5 approximately 15. Four polymorphism sites of IL-4 and IL-10 gen promoter regions were determined by PCR/RFLP. The peripheral blood monocyte (PBMC) was cultured and stimulated by lipopolysacchride (LPS). Then the contents of IL-4 and IL-10 gene promoter regions were determined by ELISA. 53 age-matched children without asthma were used as control. RESULTS: (1) The allele frequencies of-598 (C/T) site of IL-4 gene promoter was significantly different between Chinese children and children of Caucasian and Afro-American origin (P = 0.01). The allele frequency of -1082 (G/A) site, -819 (C/T) site, and -592 (A/C) site in IL-10 gene promoter was significantly different between Chinese children and their British counterparts (P = 0.01). (2) The serum total IgE level was significantly different among children with different allelic sites in IL-4 and IL-10 gene promoters. A allele in IL-10 - 1082 (G/A) site and T allele in IL-10 - 819 (C/T) site -1082 were associated with elevated total serum IgE (P < 0.01, OR = 3.16; P < 0.05, OR = 1.84). (3) The IL-10 level in the supernatant of PBMC culture of children with homozygous genotypes of -819 TT and ATA/ATA in IL-10 gene promoter after stimulation of LPS was the lowest in comparison with those in the supernatant of PBMC culture of children with other genotypes (all P < 0.05). (4) No correlation was found between -589 (C/T) site in IL-4 gene promoter and asthma. There was no significant difference between the increase of IL-4 level in the supernatant of PBMC culture of children with the two different homozygous genotypes of IL-4 gene promoter. CONCLUSIONS: (1) There is no significant correlation between the polymorphism sites in IL-4 and IL-10 gene promoters and the susceptibility to asthma among Chinese. (2) The polymorphism of IL-10 gene promoter may be an important candidate gene for severity of asthma. The allele -819T plays an important role in increase of the total serum IgE by reducing the upregulation of IL-10 gene expression.