Correlation between cholesterol content in circulating immune complexes and atherogenic properties of CHD patients' serum manifested in cell culture.

Blood serum of most patients with coronary heart disease (CHD) caused a 2-5-fold increase in the total cholesterol content of smooth muscle cells cultured from unaffected human aortic intima, i.e. possessed an atherogenic potential manifested in culture. Removal of immunoglobulins G and M from an atherogenic serum brought about a fall in its atherogenic potential. The serum deficient in immunoglobulins A retained its ability to induce the cholesterol accumulation in cells. Treatment of the CHD patients' serum with 2.5% polyethylene glycol 6000 removed the circulating immune complexes. The serum subjected to this treatment lost its atherogenicity, i.e. failed to increase the cholesterol content in cultured cells. Incubation of smooth muscle cells derived from human aortic intima with circulating immune complexes isolated from an atherogenic patients' serum caused a 1.5-3-fold rise in the intracellular cholesterol. Blood sera of most (89%) CHD patients was characterized by a high cholesterol content in circulating immune complexes. More than 75% of healthy subjects and patients without stenosis of coronary arteries had low level of cholesterol in immune complexes. Blood sera atherogenicity manifested in culture directly correlated with the cholesterol level of circulating immune complexes (r = 0.90). These findings suggest that the atherogenicity of CHD patients blood serum is due to cholesterol-containing immune complexes.

Peritoneal macrophages: a model for detecting atherogenic potential in patients' blood serum.

Human and mouse peritoneal macrophages cultured in the presence of the blood serum of patients with documented coronary heart disease showed a 2- to 3-fold rise in levels of intracellular cholesterol ester and a 1.5- to 2-fold increase in those of free cholesterol and triglycerides. This effect was observed in 83% of cases, whereas the serum of healthy subjects induced the accumulation of lipids in macrophages only in 28% of cases. These data accord with previously published observations obtained on smooth muscle cells of human aortic intima. A direct correlation was found between the accumulation of cholesterol in macrophages and in cultured smooth muscle cells of human aortic intima. The accumulation of lipids in macrophages was dose dependent and increased with time. It is assumed that a culture of peritoneal macrophages may serve as a model for identifying an atherogenic potential of patients' blood serum.

[Cholesterol-containing circulating immune complexes--a component of the blood serum in patients with ischemic heart disease that determines its atherogenic properties]. / Kholesterinsoderzhashchie tsirkuliruiushchie immunnye kompleksy-- komponent syvorotki krovi bo'lnykh ishemicheskoi bolez'niu serdtsa obuslovlivaiushchii ee aterogennos't.

In most patients with coronary heart disease (CHD) and angiographically documented stenosed 1-3 coronary arteries, serum contained cholesterol (C) in the circulating immune complexes (CIC), cholesterol levels in these complexes being directly related to serum atherogenicity, i.e. to their ability to cause a 2-5-fold accumulation of lipids in cultured smooth muscle cells (SMC) of the uninvolved human aortic intima (r = 0.91). Removal of IgG and IgM from the patients' sera led to a 75 and 37% decrease, respectively, in their atherogenic properties displayed in cultured SMC. Much more decrease in the atherogenic potential of the sera was seen in 2.5% polyethylene glycol-induced precipitation of CIC. At the same time, incubation of human aortic intimal SMC with CIC isolated from the atherogenic sera from CHD patients caused a 1.5-3-fold increase in intracellular C levels. It was suggested that CIC cholesterol was a determinant of atherogenicity of the sera from patients with coronary atherosclerosis.