Development of homogeneous assay for simultaneous measurement of apoE-deficient, apoE-containing, and total HDL-cholesterol

• Published in: Clinica chimica acta Vol. 454; pp. 135 - 142
• Main Authors: Takahashi, Yuji, Ito, Yasuki, Wada, Norio, Nagasaka, Atsushi, Fujikawa, Masato, Sakurai, Toshihiro, Shrestha, Rojeet, Hui, Shu-Ping, Chiba, Hitoshi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.02.2016
• Subjects: Analytical systems; Apolipoproteins E - blood; Apolipoproteins E - deficiency; Blood Chemical Analysis - methods; Cholesterol, HDL - blood; Enzymatic methods; Healthy Volunteers; Humans; Lipids; Enzymatic methods; Analytical systems; Lipids
• ISSN: 0009-8981; 1873-3492; 1873-3492
• DOI: 10.1016/j.cca.2016.01.013

Pathophysiological role for high-density lipoprotein (HDL) subclasses remains to be elucidated. Homogeneous assay for simultaneous measurements of apoE-deficient HDL-cholesterol (HDL-C), apoE-containing HDL-C, and total HDL-C is desired, because apoE plays important roles in lipid metabolism. The proposed assay consists of a primary reaction to remove non-HDL-C, a secondary reaction to measure apoE-deficient HDL-C, and a tertiary reaction to measure apoE-containing HDL-C. The assay is completed within 10min. For control study, 13% polyethylene glycol precipitation assay and phosphotungstate-dextran sulfate–magnesium precipitation assay were carried out. Good correlations between the control assays and the proposed assay was obtained in serum samples from patients without liver disease (n=33): r=0.987, 0.957, and 0.991 for apoE-deficient, apoE-containing, and total HDL-C, respectively. ApoE-containing HDL-C by the proposed method in healthy individuals (n=12) and patients with hyper-HDL-cholesterolemia (n=5) were 0.11±0.03 and 0.26±0.05mmol/l (4.1±1.3 and 10.1±2.0mg/dl), respectively. ApoE-containing HDL-C increased rapidly at >2.59mmol/l (100mg/dl) of total HDL-C, suggesting a unique regulating mechanism of apoE-containing HDL-C. The established homogeneous assay might be useful for clinical and epidemiological studies on apoE-deficient and apoE-containing HDL subclasses. •Homogeneous apoE-deficient, apoE-containing and total HDL-C assay is established.•Simultaneous assay can be finished within 10min.•ApoE-containing HDL-C increases rapidly at total HDL-C>100mg/dl.