CD14基因启动子区-159位点多态性在重度烧伤患者中的分布及意义

目的 了解CD14基因启动子-159C/T基因多态性与严重烧伤患者CD14 mRNA表达及血浆可溶性CD14(sCD14)水平的关系.方法 2004年6月-2006年6月,选择2个笔者单位收治的烧伤总面积大于或等于30%TBSA的患者77例,分别于伤后1、3、5、7、14、21、28 d抽取患者静脉血,采用PCR-限制性片段长度多态性法检测血浆CD14-159C/T基因多态性,酶联免疫吸附测定法、RT-PCR法检测患者血浆sCD14的含量及白细胞CD14 mRNA表达.结果 77例患者的CD14基因C-159T基因型中,CC纯合子型7例占9.1%、TC杂合子型49例占63.6%、TT等位基因纯合子型21例占27.3%,T等位基因和C等位基因分布频率分别为59.1%和40.9%.经检验表明,此研究群体达到了Hard-Weinberg平衡.7例CC纯合子型患者中并发脓毒症3例占42.9%,49例TC杂合子型并发该症38例占77.6%,21例TT等位基因纯合子型并发该症15例占71.4%.3例CC纯合子型脓毒症患者中,1例出现MODS;38例TC杂合子型脓毒症患者19例出现MODS占50.0%;15例TT等位基因纯合子型脓毒症患者10例出现MODS占66.7%.伤后7～21 d TC杂合子型、TT等位基因纯合子型患者外周血CD14 mRNA表达明显高于CC纯合子型患者(P＜0.05或P＜0.01).伤后7d TC杂合子型、TT等位基因纯合子型患者CD14 mRNA表达达高峰,分别为1.18±0.25、1.15±0.35.烧伤后TC杂合子型、TT等位基因纯合子型患者血浆中sCD14含量较高,伤后5 d CC纯合子型患者血浆sCD14含量(85±46)μg/L显著低于TC杂合子型患者(134±43)μg/L,P＜0.01];伤后21、28 d TC杂合子型、TT等位基因纯合子型患者sCD14含量明显高于CC纯合子型患者(P＜0.01).结论 大面积烧伤后CD14基因启动子-159位点多态性TT基因型可能是烧伤感染患者发生MODS的主要基因标志物之一.携带TT基因型的烧伤脓毒症患者并发MODS概率高于其他基因型.

Distribution and clinical significance of CD14 promoter-159C/T polymorphism in patients with extensive burn

Objective To investigate association of CD14-159C/T polymorphism with expression of leukocyte CD14 mRNA and plasma soluble CD14 (sCD14) level in severe bum patients. Methods Sev-enty-seven patients with total burn surfaee area equal to or over 30% TBSA were hospitalized in the First Hospital Affiliated to the PLA General Hospital and Beijing You anmen Hospital from June 2004 to June 2006. Blood samples were collected on 1at, 3rd, 5rd, 7rd, 14rd, 21rd, and 28th postburn day (PBD) for de-termination of CD14-159C/T polymorphism by PCR-subsequent restriction fragment length polymorphism (BFLP) analysis,plasma level of sCD14 and leukocyte CDI4 mRNA expression were measured by ELISA and BT-PCR. Results Frequency of the T and C allele was 59.1%, 40.9% , respectively. Seven cases (9.1%) were homozygote (CC genotype), 49 cases(63.6% ) were heterozygote (TC genotype), and 21 eases (27.3%)were TT homozygous allele, which reached the Hard-Weinberg equilibrium. Three cases with CC homozygote, 38 cases with TC heterozygote, and 15 eases with "IT homozygous allele were complicated with sepsis, ending in MODS in 1, 19, 10 cases, respectively. Expression of leukocyte CDI4 mRNA in pa-tients with TC heterozygote and TT homozygous allele peaked on 7th PBD( 1.18 ± 0.25, 1.15 ± 0.35, re-spectively), which were markedly higher than that in patients with CC homozygote during 7th-21st PBD ( P < 0.05 or P < 0.01 ). The plasma level of sCDI4 in patients with CC homozygote was significantly lower than that in patients with TC heterozygote on 5 PBD (85±46 μg/L vs 134±43 μg/L, P <0.01 ), which were higher in patients with TC heterozygote and TT homozygous allele than that in patients with CC homozy-gore on 21st, 28th PBD ( P <0.01 ). Conclusions in CDI4 gene promoter-159C/T polymorphism, the gene and protein expression of CDI4 in patients with TT, TC genotype are much higher than those in patients with CC homozygote. CDI4 gene promoter-159 C/T polymorphism with TT homozygote may be one of the major markers in extensive burn patients in whom infection may progress to MODS. Compared with other genetypes, the incidence of MODS in sepsis patients with Tr genotype increase markedly.