严重烧伤患者CD14基因多态性对高迁移率族蛋白B1表达的影响

目的 了解LPS受体CD14C-159T基因多态性对严重烧伤患者伤后高迁移率族蛋白B1(HMGB1)合成、释放的影响以及与脓毒症的关系.方法 采集35例烧伤总面积大于或等于30%TBSA患者伤后1、3、5、7、14、21、28 d静脉血.另设11名志愿者作为健康对照组.采用PCR-限制性片段长度多态性方法检测CD14-159C/T基因多态性,ELISA法检测血浆HMGB1水平,RT-PCR法检测HMGB1 tuRNA表达.对数据行χ~2检验、方差分析和t检验.结果 35例患者的CD14基因C-159T基因型中,CC纯合子型7例占20.0%、TC杂合子型16例占45.7%、TT等位基因纯合子型12例占34.3%.T等位基因和C等位基因分布的频率为57.2%和42.8%.验证表明,此研究群体达到了Hard-Weinberg平衡.在CD14C-159T基因型中,CC纯合子型患者发生脓毒症的概率较TC杂合子型、TT等位基因纯合子型低.3例CC纯合子型脓毒症患者中,仅1例死亡;9例TC杂合子型脓毒症患者中4例死亡;7例TT等位基因纯合子型脓毒症患者中4例死亡.与健康对照组比较伤后1 d患者血浆HMGB1水平即迅速升高,伤后14、21、28 d TC杂合子型、TT等位基因纯合子型患者血浆HMGB1水平均显著高于CC纯合子型(F值为3.5671、4.2035、3.8529,P<0.05或P<0.01).伤后14 d脓毒症组患者外周血白细胞HMGB1 mRNA表达量为1.5±0.5,显著高于非脓毒症组患者(1.2±0.4,t=-2.205,P<0.05).伤后7、21 d脓毒症组患者血浆HMGB1水平分别为(44±29)、(25±15)ng/mL,均高于非脓毒症组患者的(26±12)、(10±6)ng/mL(t值分别为-2.355、-3.872,P<0.05或P<0.01).结论 CD14C-159T基因多态性可显著影响严重烧伤后HMGB1的合成与释放,并与烧伤患者脓毒症易感性有关.

Influence of CD14 gene polymorphism on the expression of high mobility group box-1 protein in patients with severe burn

Objective To investigate the influence of the lipopolysaccharide receptor CD14-159C/T gene polymorphism on the synthesis and release of high mobility group box-1 protein (HMGB1) , and its relation to sepsis in patients with severe burn. Methods Venous blood from 35 patients with burn area e-qual to or larger than 30% TBSA was obtained on post burn day (PBD) 1 , 3 , 5 , 7, 14, 21, and 28 respectively. Eleven volunteers were enrolled as healthy control group (HC). CD14-159C/T gene polymorphism was detected with polymerase chain reaction ( PCR) -restriction fragment length polymorphism analysis. Plasma level of HMGB1 was determined with ELISA. Leukocyte HMGB1 mRNA expression was determined with RT-PCR. Data were processed with χ~2 test, analysis of variance, and t test. Results Among the C-159T genotype of CD14 gene in the 35 patients, the distribution frequency of the T and the C allele was respectively 57.2% and 42.8%. Seven cases (20.0% ) were homozygous for the C allele (CC) , 16 cases (45.7% ) were heterozygous (TC) , and 12 cases (34.3% ) were homozygous for the T allele (TT). Allele and genotype frequencies in cases were testified as reaching the Hard-Weinberg equilibrium. The incidence of sepsis was markedly lower in CC homozygous patients than in TC heterozygous and TT homozygous patients. Only one of the 3 septic patients in CC homozygous type died; 4 of 9 septic cases in TC heterozygous type and 4 of 7 septic cases in TT homozygous type died. Plasma levels of HMGB1 of patients were significantly elevated early on PBD 1 as compared with HC group, and higher values were found in TC heterozygous and TT homozygous patients than that in CC homozygous patients on PBD 14, 21 , 28 (with F value respectively 3. 5671, 4.2035, 3.8529, P <0.05 or P <0.01). Higher HMGB1 mRNA expression was found in septic patients as compared with non-sepsis patients on PBD 14 (1. 5 ± 0. 5 vs. 1. 2 ± 0.4, t = - 2. 205 , P < 0. 05 ). Plasma level of HMGB1 was also respectively higher in septic patients than in non-sepsis patients on PBD 7, 21 (44 ±29) ng/mL vs. (26 ±12) ng/mL, t = -2.355, P <0.05; (25 ±15) ng/mL vs. (10 ±6) ng/mL, t = -3. 872, P <0.01) ]. Conclusions CD14C-159T gene polymorphism might markedly influence the synthesis and release of HMGB1, and it is associated with increase in susceptibility of sepsis in patients with severe burn.