微流控芯片电泳测定血清小而密低密度脂蛋白及临床应用价值

Analysis of small,dense low-density lipoprotein by electrophoresis on microfluidic chip

目的建立微流控芯片电泳分离血清小而密低密度脂蛋白(sdLDL)的方法并探讨其临床应用价值。方法利用自制的微流控芯片,选择Tricine缓冲液为电泳缓冲液,SDS作为添加剂,电泳分离经硝基苯并噁二唑-C6-酰基鞘胺醇(NBD C6-ceram-ide)预染的脂蛋白,激光诱导荧光技术检测。结果大而轻低密度脂蛋白(lLDL)、sdLDL、极低密度脂蛋白(VLDL)和高密度脂蛋白(HDL)在3 min内得到有效分离。冠心病(CHD)组,sdLDL检出率显著高于正常对照组(P<0.01)。CHD患者血清经连续3次分析,sdLDL出峰时间和峰面积相对标准差分别为2.18%和2.94%。sdLDL阳性组TG水平增高,HDL-C水平降低,均与阴性组存在显著差异(P<0.01和P<0.05)。CHD患者sdLDL与三酰甘油(TG)、载脂蛋白B(apoB)呈正相关(r=0.82和0.79,P<0.0001)。结论微流控芯片电泳可望成为sdLDL的常规分析手段,用于CHD危险性的评估。

Objective To establish a method to analyze small, dense low-density lipoproteins （sdLDL） in serum by microchip capillary electrophoresis （MCE） and explore its clinical application. Methods The lipoproteins pre-stained with nitrobenzoxadiazole （NBD） C6- ceramide were separated on quartz chip, and detected by laser-induced fluorescence （LIF） detector. The electrophoresis buffer was constituted by 40 mmol/L of tricine and sodium dodeeyl sulfate （SDS） was used as the additive. Results By using the established method, the large, buoyant LDL （ 1LDL）, sdLDL, very low-density lipoproteins （VLDL） and high-density lipoprotein （HDL） were effectively separated in 3 minutes. The relative standard deviations （RSD） of sdLDL of the migration time （min） and peak areas of were 2.18% and 2.94%. The proportion of sdLDL （70.0%） in the patients with coronary heart disease （CHD） was significantly higher than that in healthy controls （7.5%, P 〈0. 001 ）. sdLDL positively related with TG and apoB （r = 0.82 and 0.79, P 〈 0. 0001 ）. TG level in sdLDL-positive group were significandy higher than that in sdLDL-negative group （ P 〈 0.01 ）, while HDL-C levels in sdLDL-positive group was significandy lower than that in sdLDL-negative group （P 〈 0. 05 ）. Conclusion The capillary electrophoresis on microchip is a simple, rapid, effective and cost-low method for the measurement of sdLDL, and its application significantly improved the estimation for CHD risk.