肿瘤坏死因子和白介素-1基因多态性与严重感染易感性和预后关系的研究

Influence of cytokine genomic polymorphisms on the susceptibility and outcome of severe sepsis

目的 探讨细胞因子肿瘤坏死因子 (TNF)α、TNFβ、白介素 (IL) 1β和IL 1受体拮抗剂 (IL 1ra)基因多态性与严重感染易感性和预后的相关性。方法 以 2 0 0 1年～ 2 0 0 2年ICU收治的5 9例严重感染患者为研究对象 ,以正常献血者为对照。提取全血基因组DNA ,应用聚合酶链反应(PCR)和限制性长度片段多态性 (RFLP)方法检测细胞因子TNFα、TNFβ和IL 1β基因多态性 ,PCR法检测IL 1ra基因内含子 2区多态性区域含有 86bp的同向重复结构可变数 (VNTR)。结果 严重感染患者TNFα等位基因TNF2 的检出率 15 3% ,显著高于对照组 (7 5 % ,P =0 0 18) ,基因型TNF2 /TNF2 在严重感染组的检出率为 10 2 % ,亦显著高于对照组 (1 5 % ,P =0 0 2 0 )。等位基因TNF2 携带者和TNF2 /TNF2 纯合子发生严重感染的相对危险度分别为 2 2 32和 7 4 72。TNFβ、IL 1β和IL 1ra基因多态性在严重感染和对照组的分布两组间无显著性差异。TNFβ等位基因TNFB2在严重感染病死患者中的检出率为 73 1% ,显著高于存活患者 (31 5 % ,P =0 0 0 0 ) ,基因型TNFB2 /B2 在病死组的检出率为 5 3 8% ,显著高于存活组 (15 2 % ,P =0 0 0 4 )。严重感染患者中TNFB2 携带者和TNFB2 /B2 纯合子患者病死的相对危险度分别为 5 897和 6 5 0 0。

Objective To investigate the correlations between the polymorphisms of TNFα,TNFβ,IL-1β and IL-1ra gene and the susceptibility or outcome of severe sepsis.Methods A prospective,consecutive entry study was made among 59 patients with severe sepsis admitted in ICU,Nanjing ZhongDa Hospital between 2001 and 2002.The genomic DNA of peripheral blood nucleated was extracted.The region containing the polymorphism sites of TNFα,TNFβ and IL-1β gene was amplified by polymerase chain reaction (PCR) and restrictive fragment length polymorphism (RFLP).The polymorphic region within intron 2 of the IL-1ra gene was amplified by PCR.Results The frequency of allele TNF 2 of TNFα was 15.3% in the 59 patients with severe sepsis,higher than that in normal controls [7.5%(P=0.018)],with an odds ratio of 2.232.The frequencies of genotype TNF 2/TNF 2 in the 59 patients with severe sepsis and normal controls were 10.2% and 1.5% respectively (P=0.020),with an odds ratio of 7.472.The polymorphisms of TNFβ,IL-1β and IL-1ra did not differ between the patients with severe sepsis and normal controls.The frequency of allele TNB 2 of TNFβ was 73.1% in the nonsurvivors,higher than in the survivors 31.5%(P=0.004),with an odds ratio of 5.897.The frequency of TNB 2/TNB 2 was increased in the nonsurvivors compared with survivors,with an odds ratio of 6.500(P=0.004).The allele frequency and genotype distribution of TNFα,IL-1β and IL-1ra did not differ between the surviors and nonsurviors.Conclusion The allele TNF 2 of TNFα NcoI polymorphism may contribute to susceptibility to severe sepsis.The allele TNFB 2 of TNFβ NcoI polymorphism may be a genomic marker indicating poor prognosis.