A two-step homogeneous assay for apolipoprotein E-containing high-density lipoprotein-cholesterol:

BackgroundApolipoprotein 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.MethodsIn 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).ResultsThe 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 per...