系统性红斑狼疮患者血浆CC趋化因子配体2水平与其启动子区-2518A/G多态性相关性研究

The level of chemokine C-C motif ligand 2 in systemic lupus erythematosus patients and its association with the 2518 A/G polymorphism in the CCL2 promoter region

目的探讨CC趋化因子配体2（CCL2）-2518A/G多态性与SLE发病的相关性及其对CCL2表达的影响。方法本研究纳入134例SLE患者及56名性别年龄匹配的健康体检者作为对照。采用ELISA检测134例SLE患者及56名健康体检者血浆CCL2水平，PCR-限制性片段长度多态性（RFLP）方法检测所有SLE患者及健康体检者CCL2-2518A/G基因型，并采用体外细胞培养方法观察基因型对PBMCs表达CCL2的影响。采用χ2检验、t检验，Mann-Whitney U检验进行统计学处理。结果SLE患者组血浆CCL2表达水平为358.5（500.1）pg/ml[中位数（四分位间距）]，高于对照组243.6（125.8）pg/ml（Z=3.892，P=0.000）。其中血浆CCL2水平高表达组的SLE患者更易患LN（χ2=7.159，P=0.007）、皮肤黏膜损伤（χ2=5.133，P=0.023），并具有较高的SLEDAI（Z=2.105，P=0.035）。结合研究个体的CCL2-2518A/G多态性基因型分析提示，携带G/G纯合子的SLE患者血浆CCL2水平为425.7（608.8）pg/ml，明显高于G/A杂合子的355.3（511.1）pg/ml及A/A纯合子的327.8（367.9）pg/ml（χ2=3.496，P=0.048）。体外实验结果显示，携带G/G纯合子的PBMCs经脂多糖刺激后CCL2表达增高较A/A纯合子的PBMCs更为明显（P〈0.05）。结论SLE患者外周血CCL2蛋白水平增高与组织损伤和高SLEDAI相关，表明CCL2可能在SLE的病理过程中起着重要作用。CCL2-2518A/G基因多态性虽与SLE发病无关，但可在炎症环境中通过促进CCL2的表达，从而影响SLE的病情。

ObjectiveTo explore the correlation between chemokine C-C motif ligand 2 （CCL2）-2518A/G polymorphism and the incidence of systemic lupus erythematosus （SLE）, and investigate the effects of CCL2-2518A/G polymorphism on the expression of CCL2.MethodsA total of 134 SLE patients and 56 sex and age matched healthy people were enrolled in this study. CCL2 plasma levels were measured by enzyme-linked immunosorbent assay（ELISA）. The 2518 A/G polymorphism in CCL2 promoter region was genotyped by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP）, and then peripheral blood mononuclear cells （PBMCs） were cultured in vitro to explore the influence of the 2518A/G polymorphism in CCL2 promoter region on the expression of CCL2. Mann-Whitney U-test, Student＇s t test and chi-squared test were used for analysis.ResultsThe plasma CCL2 level in the SLE group was 358.5（500.1） pg/ml [median （four interval）], which was significantly higher than that in the control group 243.6（125.8） pg/ml （Z=3.892, P=0.000）. Patients with high plasma CCL2 levels were more prone to have renal （χ2=7.159, P=0.007） and der-matomucosal（χ2=5.133, P=0.023） involvement, as well as much higher disease activity index （SLEDAI） scores （Z=2.012, P=0.047）. The results of the analysis of individual CCL2-2518A/G polymorphic genotypes suggested that patients with the G/G genotype had the highest CCL2 levels 425.7（608.8） pg/ml, followed by those with the G/A genotype 355.3（511.1） pg/ml and A/A genotype 327.8（367.9） pg/ml （χ2=3.496, P=0.048）. The results of in vitro experiment showed that after the stimulation of lipopolysaccharide, the expression of CCL2 in PBMCs with G/G homozygote increased more significantly than that with A/A homozygote （P〈0.05）.ConclusionThe increase of plasma CCL2 concentrations is associated with tissue injury and high SLEDAI, which suggests that CCL2 may play a crucial role in the pathogenesis of SLE. CCL2-2518A/G polymorphism is not related to the pathogenesis of SLE, but it can affect the condition of SLE by promoting the expression of CCL2 in inflammatory environment.