RESUMO
OBJECTIVE: Lipoprotein(a) - Lp(a) is an independent risk factor of atherosclerosis and its complications. In spite of the long period of Lp(a) research there is no complete understanding of its physiological role and atherogenic action. The goal of this study was to investigate the presence in human plasma of circulating autoantibodies to Lp(a) belonging to different classes of immunoglobulins, and to elucidate their relationship to the presence and severity of coronary atherosclerosis in middle aged patients with coronary heart disease. MATERIAL AND METHODS: Autoantibodies to Lp(a) and LDL level were measured in 97 men with quantitative angiography data. Among these patients 17 had intact vessels and 80 had stenoses >50% in 1 or more large coronary arteries. RESULTS: Lp(a) level in patients with coronary atherosclerosis (CA) was significantly higher (median 19.0 [95%CI 12.9-27.3] mg/dl) than in patients without CA (median 10.2 [95%CI 4.5-18.3] mg/dl, p=0.05). Level of IgG autoantibodies to Lp(a) was also elevated in patients with verified CA (264 ± 188 and 187 ± 59 RLU, respectively, p=0,003). Correlation analysis showed significant association between Lp(a) concentration and presence of CA (r=0.20, p=0.05). Level of antibodies against Lp(a) correlated with the quantity of affected coronary arteries (r=0.27, p=0.008). CONCLUSION: Plasma concentration of Lp(a) as well as elevated level of autoantibodies to Lp(a) were associated with the presence and severity of coronary atherosclerosis in examined patients.