Assessment of IgG antibodies to oxidized LDL in patients with acute coronary syndrome.

Objectives: Circulating IgG antibodies to oxidized low-density lipoprotein (anti-oxLDL) have been implicated in the development of atherosclerotic plaques. In this study, we investigated the prognostic value of IgG anti-oxLDL antibodies in patients with acute coronary syndrome (ACS).

Methods: In total 54 patients with ACS and 41 matched healthy controls were involved in this prospective study. Serum IgG anti-oxLDL levels were assessed by ELISA.

Results: Higher IgG anti-oxLDL levels were found in patients with ACS versus controls (22.8 ± 23.3 vs. 7.5 ± 5.27 EU/ml, p < 0.0001). IgG anti-oxLDL concentrations were significantly higher in ACS patients with unstable clinical complications (circulatory insufficiency, malignant arrhythmias, recurring ischaemic pain, positive stress-test, need for urgent coronary intervention or sudden cardiac death) versus those without such complications (30.0 vs. 11.7 EU/ml, p < 0.001). Twelve patients (22%) were taking statins. Patients on statins had a significant reduction in clinical complications (33%) versus patients not receiving statin therapy (61%). IgG anti-oxLDL levels were also different in these two groups (11.4 vs. 25.8 EU/ml, respectively; p = 0.03). Serum IgG anti-oxLDL levels correlated with the subsequent development of unstable coronary events. Levels of anti-oxLDL significantly decreased in response to statin therapy, independently of its lipid-lowering effect.

Conclusions: Anti-oxLDL antibodies are involved in ACS. The association of anti-oxLDL with unstable clinical complications may indicate the role of this antibody in plaque destabilization.