Associations among oxidized low-density lipoprotein antibody, C-reactive protein, interleukin-6, and circulating cell adhesion molecules in patients with unstable angina pectoris.

Oxidized low-density lipoprotein (LDL) is believed to play a key role in the development of atherosclerosis. However, the significance of anti-oxidized LDL antibody in atherogenesis is unclear. The purposes of this study were to assess whether anti-oxidized LDL antibody titers are related to other inflammatory markers of possible interest in atherosclerotic development, such as soluble cell adhesion molecules, interleukin-6, and C-reactive protein (CRP), and to determine the prognostic value of anti-oxidized LDL antibody as a predictor of cardiac events in patients with unstable angina pectoris. Sixty patients (35 men and 25 women; mean age 60 years) with unstable angina were included in this study. The levels of CRP and of intercellular adhesion molecule-1 (ICAM-1) at 24 and 72 hours after admission were significantly higher than their baseline levels (p <0.05, respectively). After adjusting for age, gender, body mass index, and statin use, anti-oxidized LDL antibodies were positively correlated with CRP (r = 0.72, p <0.001) and ICAM-1 (r = 0.68, p <0.001). Elevated anti-oxidized LDL antibodies (mean >11.37 U/ml) and CRP levels (median >2.4 mg/L) on admission were correlated with a significantly lower 16-month, event-free survival rate (Kaplan-Meier event-free survival analysis, log-rank p <0.01 and p <0.05, respectively). Multivariate analysis by logistic regression revealed that elevated levels of anti-oxidized LDL antibody (mean >11.3 U/ml) on admission were an independent risk factor for an adverse cardiac event (odds ratio 2.2, 95% confidence interval 1.5 to 10.7, p = 0.001). This study demonstrates that anti-oxidized LDL antibody expression is associated with the expression of CRP and adhesion molecules, especially ICAM-1, and is a predictor of cardiac events in patients with unstable angina pectoris. The observed elevated levels of anti-oxidized LDL antibody suggest plaque instability and may be useful for identifying patients at higher risk of a cardiac event.