Analytical Laboratory Chemistry, 92190Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan.
Research Fellow of Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo, Japan.
Ann Clin Biochem. 2022 Mar;59(2):134-143. doi: 10.1177/00045632211054406. Epub 2021 Nov 4.
Cholesterol efflux capacity (CEC), an atheroprotective function of high-density lipoprotein, is expected to be a potential biomarker for cardiovascular disease. However, CEC has not been widely introduced for application in clinical laboratories because of the complexity of the conventional CEC assay using cells and radioactive materials. Previously, we developed a novel CEC assay using immobilized liposome-bound gel beads (ILG), which solves these issues. We aimed to confirm the validation and further improve the ILG method for application in the clinical setting.
Cholesterol efflux capacity values by the ILG method assayed for shorter incubation time (4 h) were compared to those assayed for 16 h (our previous ILG method). To investigate a reference material that can correct the variation between ILG manufacturing lots, bovine serum albumin, human gamma-globulins, and globulin complexes were evaluated. CEC values were also estimated in plasmas obtained with different anticoagulants, serum treated with freeze-thaw cycles, and serum mixed with several interference substances.
The CEC of 4- and 16-h incubation times were well correlated. Globulin complexes may be used as a reference material. Plasma can be used as the specimen. The serum and stored temperature of the specimen did not largely affect CEC. Hemoglobin and chyle did not have an effect on CEC, whereas high-bilirubin serum showed elevated CEC. The effect of bilirubin was nearly canceled by subtracting basal fluorescence intensity.
Present ILG method further fulfills some requirements for application in clinical laboratory. Using this reliable simple method, evaluation for clinical significance of CEC is expected.
胆固醇流出能力（CEC）是高密度脂蛋白的一种抗动脉粥样硬化功能，有望成为心血管疾病的潜在生物标志物。然而，由于使用细胞和放射性物质的传统 CEC 测定法较为复杂，CEC 尚未广泛应用于临床实验室。我们之前开发了一种使用固定化脂质体结合凝胶珠（ILG）的新型 CEC 测定法，该方法解决了这些问题。我们旨在确认验证并进一步改进 ILG 方法，以应用于临床环境。
比较了 ILG 法测定较短孵育时间（4 小时）的胆固醇流出能力值与以前的 ILG 法（16 小时）的胆固醇流出能力值。为了研究一种可以纠正 ILG 制造批次之间差异的参考物质，评估了牛血清白蛋白、人γ球蛋白和球蛋白复合物。还估计了不同抗凝剂获得的血浆、经冻融循环处理的血清和与几种干扰物质混合的血清中的 CEC 值。
4 小时和 16 小时孵育时间的 CEC 相关性良好。球蛋白复合物可用作参考物质。血浆可作为标本。血清和标本的储存温度对 CEC 的影响不大。血红蛋白和乳糜对 CEC 没有影响，而高胆红素血清显示出升高的 CEC。胆红素的影响通过减去基础荧光强度几乎可以消除。
目前的 ILG 方法进一步满足了在临床实验室应用的一些要求。使用这种可靠且简单的方法，有望评估 CEC 的临床意义。
