ANTIBODIES TO LOW DENSITY LIPOPROTEINS MODIFIED BY MALONIDALDEHYDE: CONTENT IN BLOOD AND ROLE IN ATHEROGENESIS

Abstract

In this work, we determined the content of antibodies to low-density lipoproteins modified by malondialdehyde, the concentration of circulating immune complexes cholesterol and oxidized low-density lipoproteins in the blood of healthy individuals and patients with various manifestations of atherosclerosis. In addition, the effect of antibodies to low-density lipoproteins modified with malondialdehyde on the interaction of such lipoproteins with macrophages was studied. 253 persons were examined: healthy individuals (59 people), patients with preclinical atherosclerosis (25 people) and patients with coronary artery disease (169 people). It was found that the concentration of circulating immune complexes cholesterol in plasma was increased in patients with coronary artery disease compared with healthy individuals and patients with preclinical atherosclerosis, while oxidized low-density lipoproteins content did not differ between patients groups. At the same time, a positive correlation oxidized low-density lipoproteins plasma concentration with circulating immune complexes cholesterol content was found in patients with atherosclerosis. The plasma level of IgG antibodies to malondialdehyde-modified lipoproteins was significantly reduced in patients with coronary artery disease compared with healthy people and patients with preclinical atherosclerosis. While the level of IgM antibodies to malondialdehyde low-density lipoproteins practically did not change in patients with atherosclerosis independently of disease severity. It was shown that specific antibodies vastly reduced malondialdehyde low density lipoproteins cytotoxicity and ability to induce cholesterol esters accumulation in macrophages derived from human peripheral blood mononuclear cells. Thus, the data obtained indicate that anti-lipoprotein antibodies may have a protective effect by preventing cell death and reducing the accumulation of cholesterol esters in macrophages when they interact with modified low-density lipoproteins, i.e. prevent the foam cells formation.

Keywords

• inflammation
• atherosclerosis
• circulating immune complexes
• modified low density lipoproteins
• antibodies to modified low density lipoproteins
• macrophage apoptosis