Detection of Oxidized LDL in Plasma

描述(申请人提供)：由于60%的血浆胆固醇与低密度脂蛋白(LDL)有关，降低低密度脂蛋白是减少心血管疾病干预的主要目标之一。然而，对现有临床试验的荟萃分析一直表明，虽然临床事件的风险随着低密度脂蛋白的降低而降低，但动脉粥样硬化的进展并未停止。许多患者继续有临床事件，包括死亡，尽管已经达到低密度脂蛋白的目标水平。根据动脉粥样硬化的氧化假说，天然低密度脂蛋白不会导致动脉粥样硬化。另一方面，氧化修饰的低密度脂蛋白颗粒可以被巨噬细胞贪婪地摄取，导致泡沫细胞的形成和斑块的不稳定。我们已经开发了一些针对半胱酸(氧化形式的半胱氨酸)的特异性和高灵敏度的单抗，半胱酸是自然发生的蛋白质氧化的最常见形式之一。使用K2F1.6克隆(保存在ATCC PTA-897，美国专利6,953,666B1)的初步数据表明，与健康对照相比，高危个体可以检测到广泛的阳性信号。SBIR第一阶段的目标是在大量患有和不患有心血管疾病的患者中证明这种氧化标记物的临床意义，包括有记录的冠状动脉疾病。来自三组患者的样本将可用：(1)患有和不患有冠心病的自由生活个体，其特征是病史和内皮功能障碍(肱动脉血流介导的扩张)；(2)NIH资助的退伍军人双心研究的参与者，其临床特征是MRI和内皮功能障碍；(3)患有和不伴有CAD的2型糖尿病退伍军人，他们已经接受过低密度脂蛋白目标的治疗。这将是一项前瞻性、嵌套式病例对照单盲研究设计。公共卫生相关性：除了传统的危险因素外，血浆氧化低密度脂蛋白水平升高可能会增加未来心血管事件的风险。使用一种基于识别氧化半胱氨酸部分的独特单抗的专利保护的ELISA法，我们建议定义该氧化表位在三组独立受试者中的分布，这些受试者包括健康对照组、2型糖尿病患者和确诊的冠心病患者。

DESCRIPTION (provided by applicant): With 60% of plasma cholesterol being associated with low-density lipoproteins (LDL), reduction in LDLc is one of the primary targets for intervention to reduce cardiovascular disease. However, meta- analyses of available clinical trials have consistently demonstrated that, while the risk for clinical event is reduced with LDLc reduction, the progression of atherosclerosis is not stopped. Many patients continue to have clinical events, including death, in spite of having reached target levels for LDLc. According to the oxidation hypothesis of atherosclerosis, native LDL is not atherogenic. LDL particles that have been oxidatively modified, on the other hand, can be avidly taken up by macrophages leading to the formation of foam cells and plaque instability. We have developed a number of specific and highly sensitive monoclonal antibodies against cysteic acid (oxidized form cysteine), which is one of the most common forms of naturally occurring protein oxidation. Preliminary data using the K2F1.6 clone (deposited with the ATCC PTA-897, US patent 6,953,666B1) indicates that a wide range of positive signals can be detected in high-risk individuals as compared to healthy controls. The objective of this SBIR Phase 1 is to demonstrate the clinical significance of this oxidative marker in a large cohort of patients with and without cardiovascular disease, including documented coronary artery disease. Specimen from three cohorts of patients will be available (1) free-living individuals with and without CAD as characterized from medical history and endothelial dysfunction (brachial artery flow-mediated dilatation), (2) participants in the NIH funded Veterans Twin Heart Study characterized clinically by MRI and endothelial dysfunction, (3) veterans with type 2 diabetes mellitus with and without concomitant CAD who have been treated to LDLc goal. This will be a prospective, nested case-control single-blind study design. PUBLIC HEALTH RELEVANCE: Elevated plasma levels of oxidized LDL may contribute to the risk for future cardiovascular events beyond the traditional risk factors. Using a patent-protected ELISA assay based on a unique monoclonal antibody that recognizes an oxidized cysteine moiety, we propose to define the distribution of this oxidized epitope in three independent cohorts of subjects including healthy controls, patients with type 2 diabetes mellitus and patients with documented CAD.