Specificity of autoantibodies against oxidized LDL as an additional marker for atherosclerotic risk

LDL oxidation is a crucial step in the development and progression of atherosclerotic lesions. The detection of an increase in the anti-oxidized LDL antibody titre may thus represent a biological marker of enhanced LDL oxidation in vivo.

The occurrence of anti-oxidized LDL autoantibodies was investigated in control patients, in patients with atherosclerotic coronary artery disease, in those without clinically relevant signs of atherosclerosis, but considered at risk, and in patients with chronic alcohol-related liver disease.

Anti-oxidized LDL autoantibodies were present in the plasma of the majority of patients with overt coronary atherosclerosis. An increased antibody titre can also be detected well before the onset of clinically relevant signs of the atherosclerotic disease in patients classically considered at risk, indicating the occurrence of in-vivo LDL oxidation during atherosclerosis development. The specificity of molecular targets (LDL) for oxidative modifications is supported by the demonstration that anti-oxidized LDL autoantibodies are absent in the plasma of alcoholic patients who exhibit a marked increase in biological markers of oxidative stress but do not classically develop atherosclerosis.

These data demonstrate that the occurrence of anti-oxidized LDL autoantibodies could be specifically related to the promotion and progression of atherosclerosis and is not a simple epiphenomenon of any oxidative process occurring in vivo.