Abstract 16386: Establishment of Enzyme-Linked Immunosorbent Assay for Oxidized High Density Lipoprotein and its Clinical Application for Cardiovascular Risk Assessment
Background: Observational studies have shown that plasma HDL-C levels are negatively correlated with cardiovascular events. HDL particles have a variety of anti-atherogenic functions such as cholesterol efflux and its transport to the liver. However, in vitro studies also elucidated that HDL from coronary artery disease patients become dysfunctional or even proinflammatory. One possible mechanism for formation of dysfunctional HDL is the oxidation of HDL component. Therefore, the quantification of oxidized HDL (Ox-HDL) could be an useful and easy strategy to assess the quality or functionality of HDL.
Methods: Using DLH3 antibody that can specifically recognize oxidized phosphatidylcholine, we have developed a sandwich enzyme-linked immunosorbent assay (ELISA) for Ox-HDL. We defined forced-oxidation of 1 mg/L HDL phospholipids (HDL-PL) as 1 U/L Ox-HDL. We analyzed the serum of 118 healthy normolipidemic controls and 173 dyslipidemic outpatients respectively.
Results: Intra and inter-assay coefficients of variation for this ELISA were both less than 15%. In healthy controls, the serum Ox-HDL levels were 28.3 ± 4.9 U/L (mean ± SD). Ox-HDL levels were moderately correlated with HDL-PL levels (r=0.59), therefore we also evaluated Ox-HDL/HDL-PL ratio, which represents what proportion of phospholipids is oxidized in the HDL fraction. Ox-HDL/HDL-PL ratio in healthy controls was 0.232 ± 0.036. In dyslipidemic patients treated with drugs, the serum Ox-HDL levels were 27.2 ± 8.7 U/L, displayed quite a high variability ranging from 7.2 to 62.1 U/L. The serum Ox-HDL levels correlated positively with serum HDL-C levels and were extremely high (50.4 ± 13.3 U/L) in patients with hyperalphalipoproteinemia due to CETP deficiency. On the other hand, patients treated with probucol, which is a potent anti-oxidative anti-hyperlipidemic drug, showed significantly lower Ox-HDL (18.7 ± 6.6 vs 29.7 ± 7.7, p<0.001) and Ox-HDL/HDL-PL ratio (0.206 ± 0.045 vs 0.223 ± 0.044, p=0.043) than those without probucol, suggesting that probucol may prevent oxidation of HDL.
Conclusion: Our sandwich ELISA for Ox-HDL showed that Ox-HDL levels are very high in CETP-deficient patients, suggesting the presence of dysfunctional HDL. Probucol may prevent the formation of these Ox-HDLs.
Author Disclosures: T. Okada: None. T. Ohama: None. M. Sumida: None. Y. Katayama: None. K. Kanno: None. H. Matsuda: None. M. Sairyo: None. Y. Zhu: None. A. Saga: None. T. Kobayashi: None. D. Masuda: Research Grant; Significant; Merck Sharp & Dohme Corp.. M. Koseki: None. M. Nishida: None. N. Kayahara: None. Y. Sakata: None. S. Yamashita: Research Grant; Modest; Kyowa Medex Co., Ltd.. Research Grant; Significant; Merck Sharp & Dohme Corp..
- © 2016 by American Heart Association, Inc.