Changes in apolipoprotein E-containing high-density lipoprotein (HDL) have little impact on HDL-cholesterol measurements using homogeneous assays in normolipidemic and dyslipidemic subjects

• Published in: Clinica chimica acta Vol. 470; pp. 56 - 63
• Main Authors: Sasamoto, Kenta, Hirayama, Satoshi, Kon, Mika, Seino, Utako, Ueno, Tsuyoshi, Nagao, Yuki, Hirayama, Akiko, Isshiki, Miwa, Idei, Mayumi, Yano, Kouji, Miida, Takashi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.07.2017
• Subjects: Adult; Apolipoproteins E - blood; Blood Chemical Analysis - methods; Blood Specimen Collection; Case-Control Studies; Cholestasis; Cholesterol, HDL - blood; Cholesteryl ester transfer protein; Dyslipidemias - blood; Female; Homogeneous HDL-C assay; Humans; Lecithin:cholesterol acyltransferase; Lipoproteins, HDL - blood; Male; Middle Aged; Prebeta1-HDL; Temperature; Young Adult; γ-LpE; CETP; apoAI; CDC; PT; Lecithin:cholesterol acyltransferase; apoE; LCAT; apoB; HDL-C; PBC; Native 2D-gel; PLTP; Prebeta1-HDL; ABCA1; CE; DTNB; rHDL; Cholesteryl ester transfer protein; DCM; γ-LpE; TG; RMP; Homogeneous HDL-C assay; ABCG1; Cholestasis; apoE-HDL
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/j.cca.2017.04.018

High-density lipoprotein-cholesterol (HDL-C) is generally measured using several homogeneous assays. We aimed to clarify whether apolipoprotein E-containing HDL (apoE-HDL) subfractions are altered during storage, and if so, whether such changes affect the HDL-C concentration measured using homogeneous assays. We stored serum from normolipidemic (n=32) and dyslipidemic (n=17) subjects at 4°C for up to 7days. ApoE-HDL subfractions were analyzed using native 2-dimensional gel (native 2D-gel) electrophoresis. HDL-C concentrations were determined using 2 precipitation and 4homogeneous assays. Native 2D-gel electrophoresis revealed variously sized apoE-HDL subfractions. After 4h incubation at 37°C, subfractions of smaller particles were converted into larger particles by lecithin:cholesterol acyltransferase (LCAT) activity. After 7days storage at 4°C, the smaller subfractions were decreased in the normolipidemic group, accompanying increases in larger subfractions, whereas changes in the respective subfractions varied among individuals in the dyslipidemic group. HDL-C concentrations were significantly lower after storage at 4°C in all assays, except that using Sekisui Medical's reagent. Therefore, changes in HDL-C concentration and apoE-HDL subfractions were independent of each other. ApoE-HDL subfractions change during storage, but these changes are not linked to those in HDL-C concentration measured using homogeneous assays. •There are several apoE-containing HDL (apoE-HDL) subfractions in serum.•Smaller apoE-HDL subfractions increased in size by LCAT after 4h-incubation at 37°C.•ApoE-HDL subfractions were altered during 7days-storage even at 4°C.•Changes in apoE-HDL subfractions did not affect HDL-C levels measured using homogeneous assays.