Novel diagnosis of oxidized LDL in serum using monoclonal antibody

随着人们对动脉壁低密度脂蛋白氧化致动脉粥样硬化机制的认识不断加深，循环氧化低密度脂蛋白的临床重要性还不是很清楚，这主要是因为缺乏一种灵敏的方法来检测循环中氧化低密度脂蛋白的水平。尽管许多研究人员测量了血浆中的硫代巴比妥酸活性物质，如过氧化脂质和异前列腺素，但没有人直接测量氧化修饰的低密度脂蛋白的形成。最近，用制备的抗丙二醛修饰的低密度脂蛋白(MDA-LDL)和抗铜OxLDL的鼠单抗进行免疫分析表明，循环中的OxLDL或MDA-LDL存在于人的血浆中，并且在冠心病患者中发现更高的水平。然而，这些研究并未将OxLDL与丙二醛-低密度脂蛋白区分开来，因为抗铜OxLDL的单抗与丙二醛-低密度脂蛋白发生交叉反应。在体内氧化低密度脂蛋白的过程中会产生大量的活性脂质过氧化产物，这一点越来越明显。在动脉粥样硬化动物模型apoE基因敲除小鼠的研究中，抗氧化型低密度脂蛋白的自身抗体识别脂蛋白氧化过程中形成的复杂结构的不同表位或在不同病变部位独立形成的表位。我们开发了一种独特的单抗Fohla/DLH3，它通过使用人动脉粥样硬化斑块的匀浆作为抗原来特异性地对抗氧化磷脂酰胆碱(OxPC)，而不针对天然的低密度脂蛋白、丙二醛-低密度脂蛋白、乙酰化低密度脂蛋白或糖化低密度脂蛋白。将该抗体与载脂蛋白B抗体结合，建立了循环氧化型低密度脂蛋白的酶免疫分析方法。本研究旨在探讨动脉粥样硬化性疾病患者血浆氧化低密度脂蛋白水平的临床特点。

Our increasing knowledge of the atherogenic mechanisms of oxidation of LDL in the arterial wall, the clinical importance of circulating OxLDL is poorly understood, mainly because of a lack of a sensitive method to specifically detect circulating OxLDL levels. Although a number of investigators have measured thio-barbituric acid reactive substances in plasma, such as lipid hydroperoxides and isoprostanes, none have directly measured the formation of oxidatively modified LDL. Recently, immunoassays using murine monoclonal antibodies prepared against malondialdehyde-modified LDL (MDA-LDL) and against copper OxLDL demonstrated that circulating OxLDL or MDA-LDL exists in human plasma, and higher levels are found in patients with coronary heart disease (CHD). these studies, however, OxLDL was not distinguished from MDA-LDL because the monoclonal antibody against copper OxLDL cross-reacts against MDA-LDL. It is becoming clear that a large number of reactive lipid peroxidation products are generated in vivo during the oxidation of LDL. A study on apoE knockout mice, an animal model for the development of atherosclerosis, that auto-antibodies against OxLDL recognize different epitopes of complex structures formed during oxidation of lipoproteins or epitopes formed independently at different lesion sites.We have developed a unique monoclonal antibody FOHla/DLH3 that reacts specifically against oxidized phosphatidylcholine (OxPC) by use of a homogenate of atheromatous plaques of human aorta as an antigen but not against native LDL, MDA-LDL, acetylated LDL, or glycated LDL. By use of this antibody in combination with an anti-apoprotein B antibody, an enzyme immunoassay of circulating OxLDL was developed. The present study, the clinical characteristics of plasma OxLDL levels in patients with atherosclerotic disease were investigated.