The lipid and lipoprotein profiles of apo B-carrying particles in remnant-like lipoproteins isolated from plasma in sudden cardiac death cases

Objective: Remnant-like lipoprotein particles (RLP) are known as a subset of TG-rich lipoproteins which possess proatherogenic properties. In this study we have elucidated the characteristics of apoB carrying lipoprotein particles in RLP isolated from plasma in sudden cardiac death (SCD) cases and in coronary artery disease (CAD) patients. Methods: Lipids and lipoproteins, especially apoB-48 and apoB-100, were analyzed in plasma and in RLP from SCD and CAD cases with full stomach. Results: SDS-PAGE and ELISA showed the predominance of apoB-100 in RLP compared with apoB-48. The main peak of RLP fractionated by HPLC and monitored by TC and TG revealed the particle size at VLDL or IDL, similar to those from CAD patients. The main peak of RLP monitored by apoB-48 revealed the particle size smaller than those monitored by apoB-100 in both cases. RLP-TG/total TG ratio was shown to be significantly higher in SCD cases than in control death cases (P < 0.001) in spite of the same fatty acid composition in RLP between the cases. Conclusion: These results suggested that the major subset of apoB particles in RLP isolated from plasma in SCD cases was apoB-100 carrying VLDL remnants, not apoB-48 CM remnants, which was identical with RLP in CAD patients.