Clinical significance of antibody against oxidized low density lipoprotein in patients with atherosclerotic coronary artery disease

Abstract

Serum anti-Ox-LDL titer not only can predict a presence of atherosclerotic CAD but also may be a marker of plaque instability. Low density lipoprotein oxidation may play an important role in the development of plaque instability.

Antibodies to Oxidized Low-Density Lipoproteins and Angiographically Assessed Coronary Artery Disease in White Patients

“…These negative findings differ from previous results. According to Inoue et al, 9 the oxLDLAb titer was higher in 108 Japanese patients who had angiographically confirmed CAD than in 31 patients who had chest pain but no significant CAD. Because these authors also reported higher oxLDLAb titers in 39 patients with acute MI than in 24 patients with no CAD, 14 they contended that the oxLDLAb titer would be higher in the patients with unstable angina and acute MI than in those with stable effort angina and therefore could allow discrimination between patients with these conditions.…”

“…However, consistent with our present results, they also found no significant differences between the multivessel and single-vessel CAD groups and the control subjects. 9 High plasma levels of oxLDLAbs have also been associated with carotid artery plaque instability in another study of Japanese patients, 30 but conflicting results on the association with carotid atherosclerosis exist in whites. 15,31 A more recent study, in which the ethnicity of case and control subjects was not specified, showed higher IgG oxLDLAb titer in 8 patients with acute MI, compared with 15 patients with unstable angina, 17 patients with stable CAD, or 8 subjects with normal coronary arteries.…”

“…The latter explanation is likely to apply to at least 2 of the aforementioned studies in which the number of cases was small and largely exceeded that of control subjects. 9,14 Equally important, it should be acknowledged that coronary angiography focuses on the arterial lumen, rather than on the arterial wall, whereas it has become widely recognized that plaques prone to rupture ("vulnerable plaques") are not those that that yield a high degree of stenosis, eg, the very advanced, fibrotic, and calcified atherosclerotic lesions. 33 It has been established that lesion growth goes hand in hand with compensatory dilatation of the artery wall and that even relatively large lipid-rich vulnerable ) in patients of GENICA study classified by coronary artery findings at angiography.…”

“…In this regard, we would like to point out that (1) our study was the largest ever performed to investigate the biological role of antibodies to oxLDL in patients with angiographically assessed CAD, to the best of our knowledge 9,[11][12][13][14]32,35 ; and (2) given its total sample size, it had 99% power to detect, with a 1-way ANOVA, an effect size (eg, the variance of the mean divided by the within-group variance) of 0.61, on the basis of the assumptions made earlier.…”

“…7 Oxidative modification of LDL induces immunogenic epitopes in the LDL molecule, 8 thus leading to formation of antibodies against oxLDL (oxLDLAbs) that are detectable in sera in the majority of patients with advanced atherosclerotic lesions 9 and can be measured as a tool for investigating the mechanisms of atherogenesis. 10 Several studies demonstrated an increased titer of oxLDLAbs in patients with atherosclerotic coronary artery disease (CAD), 9,[11][12][13] acute myocardial infarction (MI), 14 and cerebral or peripheral artery disease. 15,16 In contrast, other studies found no such positive relationship between oxLDLAb titers and cardiovascular (CV) phenotypes.…”