Anti-Apo B-100 Autoantibody is a Marker of Unstable Coronary Plaque

Cardiovascular diseases (CVD) are a global leading cause of mortality. However, few biomarkers are available to predict future coronary plaque rupture. We have recently demonstrated that low levels of anti-apolipoprotein B-100 autoantibody (anti-apo B-100 Ab) correlated with an increased CVD risk in Japanese patients with diabetes. In the present study, we examined the relationship between serum anti-apo B-100 Ab levels and coronary plaque characteristics in patients undergoing elective percutaneous coronary intervention (PCI).

We conducted iMAP^®-intravascular ultrasound (IVUS) in 88 Japanese male patients undergoing elective PCI, and the five consecutive slices of IVUS images at the center of the most stenotic culprit lesion were used for identifying the plaque characteristics. The serum levels of anti-apo B-100 Ab against synthetic peptides (p45 or p210) were measured using a homemade enzyme-linked immunosorbent assay.

Serum IgG levels of anti-apo B-100 Ab against both native p45 and p210 (IgG _N-p45 and IgG_N-p210) and malondialdehyde (MDA)-modified p45 and p210 (IgG_MDA-p45 or IgG_MDA-p210) showed a negative correlation with plaque burden in total male patients undergoing elective PCI. Additionally, both IgG_N-p45 and IgG_N-p210, but neither IgG_MDA-p45 nor IgG_MDA-p210, correlated negatively with necrotic and positively with fibrotic components of iMAP^®-IVUS plaque characteristics in the patients with ＜1 month statin treatment before elective PCI ("statin-untreated" group). There was no significant correlation between anti-apo B-100 Ab and any plaque characteristics in the patients with statin treatment for 1 month or more before elective PCI ("statin-treated" group).

Measuring serum levels of anti-apo B-100 Ab might be helpful in the evaluation of unstable coronary plaque in male CVD patients without statin treatment.