DETECTION OF AUTOANTIBODIES AGAINST OXIDIZED LOW-DENSITY LIPOPROTEINSAND OF IGG-BOUND LOW-DENSITY LIPOPROTEINS IN PATIENTS WITH CORONARY-ARTERY DISEASE

The role of oxidized low-density lipoprotein (ox-LDL) in the pathogene sis of atherosclerosis has been the object of intense investigation. I t has been proposed that, due to the antigenic properties of ox-LDL, t he anti-ox-LDL antibody titre could represent a useful index of in viv o LDL oxidation, On the other hand, LDL immune complexes (LDL-IC) have been demonstrated in patients with coronary disease and could play an atherogenic role. The goal of our study was to investigate anti-malon dialdehyde (MDA)-LDL autoantibodies and LDL-IC in a cohort of patients with coronary artery disease. Seventy control subjects and 70 coronar y angiographically documented patients were compared; in addition 32 h ealthy male nonsmokers were compared with 32 healthy male smokers (> 1 0 cigarettes/day). All patients were matched for age and cholesterolem ia. Enzyme-linked immunosorbent assay was used to measure anti-MDA-LDL autoantibodies and LDL-IC, Titres of anti-MDA-LDL autoantibodies were not larger in patients with documented coronary artery stenosis and i n smokers than they were in controls and non-smokers. The titre of LDL -IC was not higher in patients with coronary artery stenosis than in c ontrols. The results thus indicate that in populations matched for age and cholesterolemia the titres of anti-MDA-LDL autoantibodies and the titre of LDL-IC are not increased in patients suffering from coronary artery stenosis. Furthermore, cigarette smoking does not induce highe r titres of anti-MDA-LDL autoantibodies in healthy patients.