Increased autoantibodies against oxidized low-density lipoprotein in coronary circulation in patients with coronary spastic angina

Oxidized low-density lipoproteins are important in the progression of ather osclerosis. Autoantibodies against malondialdehyde-modified low-density lip oproteins have been reported to be predictive of the progression of atheros clerosis. This study sought to examine whether plasma levels of autoantibod ies against oxidized low-density lipoprotein increase in the coronary circu lation in patients with coronary spastic angina. The authors examined plasm a antioxidized low-density lipoprotein antibody levels (activity unit value s (AcU)/mL) simultaneously in the coronary sinus and the aortic root in 20 patients with coronary spastic angina, 23 patients with stable exertional a ngina, and 15 control subjects by measuring plasma levels of immunoglobulin G (IgG) autoantibodies against malondialdehyde-modified low-density lipopr oteins by enzyme-linked immunosorbent assay. The plasma antioxidized low-de nsity lipoprotein antibody levels (AcU/mL) in the coronary sinus increased in coronary spastic angina (38 +/- 16) compared with stable exertional angi na (23 +/- 7) and control subjects (20 +/- 6) (p less than or equal to 0.00 01). The levels (AcU/mL) in the aortic root also increased in coronary spas tic angina (33 +/- 12) compared with stable exertional angina (23 +/- 7) an d control subjects (20 +/- 6) (p < 0.005). Furthermore, the coronary sinus- arterial differences of the levels (AcU/mL) were also higher in coronary sp astic angina (5 <plus/minus> 9) than in stable exertional angina (0 +/- 6) and healthy subjects (-1 +/- 5) (p < 0.05). The generation of malondialdehy de-modified low-density lipoproteins is reported to be associated with athe rothrombosis. These findings suggest that elevated levels of autoantibodies against malondialdehyde-modified oxidized low-density lipoproteins in coro nary circulation are associated with the development of atherothrombosis fr om the progression of atherosclerosis rather than with the extent of corona ry atherosclerosis in patients with coronary spastic angina.