Autoantibodies against modified low-density lipoproteins in coronary artery disease

Objectives: To evaluate the importance of different autoantibodies against modified low-density lipoprotein (LDL) in patients with coronary artery disease (CAD). Background: Previous studies of autoantibodies against LDL have shown that patients with CAD have increased titers of autoantibodies against LDL modified by copper and malondialdehyde (MDA), whereas there is a lack of information about autoantibody titers against LDL modified by hypochlorite (HOCl). Studies of autoantibodies in relation to severity of atherosclerosis are few and have reached divergent results. Furthermore, no data exist on the relationship between autoantibody titers and prognosis. Methods: Titers of autoantibodies against copper-, MDA- and HOCl-modified LDL were determined in serum by ELISA. Autoantibody titers in young male survivors of a first myocardial infarction were compared with those of healthy controls and related to coronary angiographic findings and to prognosis during 11 years of follow-up. Results: Patients had higher titers of autoantibodies against LDL modified by copper and MDA than controls. In contrast, no consistent associations were found between autoantibody titers and global severity of coronary atherosclerosis or number and severity of coronary stenoses and prognosis. Conclusions: The prognostic value of autoantibodies against modified LDL is limited in young postinfarction patients despite the fact that autoantibody titers against copper- and MDA-modified LDL are raised compared with healthy controls. Furthermore, the results indicate that autoantibodies against modified LDL are not protective in later stages of coronary atherosclerosis.