Antibodies against oxLDL and acute coronary syndrome.

BACKGROUND The oxidation of low-density lipoprotein (oxLDL) induces the formation of immunogenic epitopes in molecules. The presence of autoantibodies against oxLDL has been demonstrated in the serum of patients with coronary artery disease (CAD). However, the role of these autoantibodies in the pathophysiology of acute coronary syndromes (ACS) and their clinical significance remain undefined. OBJECTIVE To evaluate the association between antibodies against oxLDL and ACS. METHODS Titers of IgG autoantibodies against oxLDL by copper (anti-oxLDL) and anti-D synthetic peptide derived from apolipoprotein B (antipeptD) were determined by Enzyme-linked immunosorbent assay (ELISA) in 90 patients, in the first 12 hours of ACS (cases) and in 90 patients with chronic CAD (controls). RESULTS The results showed that the titers of anti-oxLDL were significantly higher (p = 0.017) in cases (0.40 +/- 0.22) than in controls (0.33 +/- 0.23). On the other hand, the titers of antipeptD were significantly lower (p < 0.01) in cases (0.28 +/- 0.23) than in controls (0.45 +/- 0.30). The difference in the titers of both antibodies between the two groups was independent of age, sex, hypertension, diabetes mellitus, dyslipidemia, body mass index, smoking, lipid profile, statin use and family history of CAD. CONCLUSION The results showed that the titers of anti-oxLDL were significantly higher in patients with acute coronary syndrome as compared to patients with coronary artery disease and may be associated with atherosclerotic plaque instability.