A two-step homogeneous assay for apolipoprotein E-containing high-density lipoprotein-cholesterol. (January 2019)

• Record Type: Journal Article
• Authors: Takahashi, Yuji; Ito, Yasuki; Sakurai, Toshihiro; Wada, Norio; Nagasaka, Atsushi; Fujikawa, Masato; Chiba, Hitoshi; Hui, Shu-Ping
• Is Part Of: Annals of clinical biochemistry. Volume 56:Number 1(2019:Jan.)
• Page Start: 123
• Page End: 132
• Publication Date: 2019-01
• Subjects: Lipids -- analytical systems -- enzymatic methods; Clinical chemistry -- Periodicals; Clinical biochemistry -- Periodicals; 616.075
• DOI: 10.1177/0004563218795212
• Languages: English
• ISSNs: 0004-5632

Abstract

Background: Apolipoprotein E-containing high-density lipoprotein shows antiatherogenic properties in vitro . There is a need for a homogeneous assay to determine the concentration of apolipoprotein E-containing high-density lipoprotein for in vivo studies. Methods: In the proposed homogeneous assay, lipoproteins other than apolipoprotein E-containing high-density lipoprotein were eliminated in the first step. Apolipoprotein E-containing high-density lipoprotein-cholesterol was measured in the second step. The control study used a 13% polyethylene glycol precipitation assay (control assay). Results: The homogeneous assay showed good performance in validation studies. In subjects with normal liver function ( n = 78), a significant correlation was found between the control assay and the homogeneous assay ( r = 0.824). Serum apolipoprotein E-containing high-density lipoprotein cholesterol concentrations, determined by the control assay and the homogeneous assay, respectively, were 0.05 (0.04–0.10) (median [25th–75th percentile]) mmol/L and 0.10 (0.06–0.13) mmol/L for healthy individuals ( n = 12), and 0.03 (0.01–0.13) mmol/L and 0.02 (0.01–0.02) mmol/L for patients with cholestasis ( n = 6). The results indicate that the homogeneous assay recovers cholesterol contained in physiological apolipoprotein E-containing high-density lipoprotein, but not in pathological apolipoprotein E-containing high-density lipoprotein from cholestatic patients. Conclusions: The proposed two-step homogeneous assay enables selective measurement of physiological apolipoprotein E-containing high-density lipoprotein cholesterol in common autoanalysers. This assay might uncover a role for apolipoprotein E-containing high-density lipoprotein in physiological conditions.