Ito Yasuki, Ohta Motoko, Ikezaki Hiroaki, Hirao Yuhko, Machida Asako, Schaefer Ernst J, Furusyo Norihiro
R&D Center, Denka Seiken Co., Ltd., Tokyo, Japan.
Department of General Internal Medicine, Kyushu University Hospital, Fukuoka, Japan.
J Appl Lab Med. 2018 Mar 1;2(5):746-756. doi: 10.1373/jalm.2017.024554.
Low-density lipoprotein (LDL) is measured by its cholesterol content (LDL-C), but it has been suggested that LDL triglyceride (LDL-TG) may also be related to coronary artery disease risk. LDL-TG can be measured after ultracentrifugation or electrophoresis, but these are labor intensive methods, indicating the need for an automated homogeneous assay.
TG-rich lipoproteins (TRLs), LDL, and HDL were isolated by ultracentrifugation and used to determine optimal characteristics of surfactants and various enzymes for assay development. We analyzed assay precision and linearity, and compared results with those obtained after ultracentrifugation. Serum samples from a large population study (n = 12284 subjects) were used to generate reference intervals for LDL-TG and to determine levels in various types of hyperlipidemia.
An assay for LDL-TG has been developed by use of surfactants 1 and 2, and enzymes to measure LDL-TG directly on an automated analyzer. There was an excellent correlation between results obtained with this assay and after isolation of LDL by ultracentrifugation. When the assay was applied to serum samples from normal and hyperlipidemic subjects, median normal values were 0.09 mmol/L, with significant median elevations observed in subjects with increased LDL-C, hypertriglyceridemia, combined hyperlipidemia, and hyperchylomicronemia of 0.19, 0.18, 0.28, and 0.43 mmol/L, respectively, as compared with mean LDL-C values in these subjects of 2.25, 4.01, 2.66, 3.96, and 2.43 mmol/L, respectively.
We have developed an automated homogeneous assay for LDL-TG for potential use in research and clinical laboratories, and documented that the TG molar content of LDL is about 5% of its cholesterol content.
低密度脂蛋白（LDL）通过其胆固醇含量（LDL-C）来测定，但有研究表明，LDL甘油三酯（LDL-TG）也可能与冠状动脉疾病风险相关。LDL-TG可通过超速离心或电泳后进行测量，但这些方法劳动强度大，表明需要一种自动化的均相测定法。
通过超速离心分离富含甘油三酯的脂蛋白（TRL）、LDL和HDL，并用于确定表面活性剂和各种酶的最佳特性以用于分析方法开发。我们分析了分析的精密度和线性，并将结果与超速离心后获得的结果进行比较。来自一项大型人群研究（n = 12284名受试者）的血清样本用于生成LDL-TG的参考区间，并确定各种类型高脂血症中的水平。
利用表面活性剂1和2以及酶开发了一种直接在自动分析仪上测量LDL-TG的分析方法。该分析方法获得的结果与通过超速离心分离LDL后获得的结果之间具有极好的相关性。当将该分析方法应用于正常和高脂血症受试者的血清样本时，正常中位数为0.09 mmol/L，在LDL-C升高、高甘油三酯血症、混合性高脂血症和高乳糜微粒血症受试者中观察到中位数显著升高，分别为0.19、0.18、0.28和0.43 mmol/L，而这些受试者的平均LDL-C值分别为2.25、4.01、2.66、3.96和2.43 mmol/L。
我们开发了一种用于LDL-TG的自动化均相分析方法，可潜在用于研究和临床实验室，并证明LDL的TG摩尔含量约为其胆固醇含量的5%。
