Dyslipidemia, inflammation and immunological processes play a key role in the development of atherosclerosis. This study investigates the relationship of different phenotypes of low-density lipoprotein (LDL) and high-density lipoprotein (HDL), human antibodies G classes against oxLDL (IgG anti-oxLDL antibodies) and inflammatory marker pentraxin-3 (PTX3) in patients with ST-segment elevation acute myocardial infarction (STEMI). Among STEMI patients with different Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX) score, we analyzed predictive abilities of these biomarkers to assess disease outcome.

Material and methods:
In 69 STEMI, 21 patients with stable angina pectoris (AP) and 67 healthy controls, IgG anti-oxLDL antibodies and PTX3 were determined by ELISA. Gradient gel electrophoresis was used for lipoprotein subclasses separation.

We found significantly lower HDL and LDL diameters (p<0.001 and p<0.001, respectively) and higher PTX3 concentration (p<0.001) in patients than in controls. Control subjects with small-sized HDL and LDL B phenotype had significantly higher IgG anti-oxLDL antibody levels (p=0.015), whereas STEMI patients with the same profile had higher PTX3 concentration (p=0.005). STEMI patients with intermediate SYNTAX score had lower levels of IgG anti-oxLDL antibodies (p=0.008). Multivariate logistic regression analysis showed that smaller LDL diameter was an independent predictor of intermediate SYNTAX score (OR=0.370; p=0.019).

Smaller LDL and HDL particles are associated with elevated IgG anti-oxLDL antibodies in healthy subjects, but with increased PTX3 level in STEMI patients. In addition, we found that smaller LDL size was independent predictor of higher SYNTAX score. Further studies are needed to expand our preliminary observations.