Oxidized Low-Density Lipoprotein-ß2-Glycoprotein I Complex But Not Free Oxidized LDL Is Associated With the Presence and Severity of Coronary Artery Disease.

ABSTRACT

Oxidized low-density lipoprotein (oxLDL) and ß2-glycoprotein I (ß2GPI) have been identified in human atherosclerotic lesions and when complexed have been implicated as a pro-atherothrombotic antigen. We examined the association of free oxLDL and oxLDL-ß2GPI complex in patients with coronary artery disease who underwent elective cardiac catheterization. Serum was collected from patients with suspected coronary artery disease immediately before elective cardiac catheterization who were either treated (n = 385) or not treated (n = 150) with statins and from healthy volunteers (n = 134). OxLDL and oxLDL-ß2GPI complex levels were determined by enzyme-linked immunosorbent assay. Disease severity was defined angiographically as none-minimal (<20%), moderate (20% to 75%), and severe (>75%) luminal diameter obstruction of any major coronary vessel. Both oxLDL and oxLDL-ß2GPI complex were lower in patients on statins (p <0.001). In statin-naive patients, oxLDL-ß2GPI complex, but not free oxLDL, was associated with severe coronary artery disease (p = 0.036). However, no association was observed in patients on statins. LDL4 and triglycerides increased with oxLDL-ß2GPI complex quartiles (p = 0.001). OxLDL-ß2GPI complex (>0.32 U/ml) was predictive of severe atherosclerosis by receiver-operating characteristic curve analysis in statin-naive patients (area under the curve 0.66, p = 0.002). In conclusion, oxLDL-ß2GPI appears more predictive of coronary artery disease severity than oxLDL alone in statin-naive patients.