Characteristics of Lipoprotein(a)-Containing Circulating Immune Complexes as Markers of Coronary Heart Disease.

We studied the composition of circulating immune complexes precipitated in the presence of various concentrations of polyethylene glycol in patients with coronary heart disease (CHD) and high concentration of lipoprotein(a) - Lp(a). Precipitation of highly purified Lp(a) preparation with polyethylene glycol was evaluated. The contents of Lp(a), autoantibodies to Lp(a), IgG, and IgM in circulating immune complexes isolated from the sera of donors and CHD patients with normal and high levels of Lp(a) were measured. Circulating immune complexes containing Lp(a) were detected in the plasma of CHD patients with high Lp(a) concentrations. The presence of high concentrations of Lp(a), autoantibodies to Lp(a), and circulating immune complexes in CHD patients suggests that immunological factor contributes to high atherothrombogenicity of Lp(a).