Detection of circulating IgG antibodies to apolipoprotein B100 in acute myocardial infarction

A number of studies have reported an association between increased levels of antibodies against oxidized low-density lipoprotein (oxLDL) and cardiovascular disease, but the anti-oxLDL antibody has not been confirmed to serve as an effective biomarker for prediction of acute myocardial infarction (AMI). Apolipoprotein B100 (ApoB100)-derived peptide fragments generated by proteolytic degradation and aldehyde modification are the major antigens in oxLDL, and so the present work was undertaken to detect circulating IgG for Apo-B100-derived peptide antigens. An in-house enzyme-linked immunosorbent assay (ELISA) was developed with eight ApoB100-derived peptide antigens (Ag1-Ag8) to detect circulating anti-ApoB100 IgG levels in 267 patients with AMI and 201 control subjects. Binary logistic regression analysis revealed that circulating IgG for Ag1 was significantly higher in the patient group than the control group (P < 0.001) after adjustment for age, gender, smoking, hypertension, diabetes and circulating levels of cholesterol, HDL, LDL, ApoA and ApoB100. None of the other seven antigens detected an increase in IgG levels in AMI patients compared with control subjects. Spearman correlation analysis showed no correlation between IgG antibody for Ag1 and clinical characteristics. In conclusion, the linear peptide antigens derived from ApoB100 may be suitable for the development of an ELISA antibody test for prediction of AMI, although further confirmation is still needed in large-scale clinical studies.