Remnant lipoprotein cholesterol homogenous assay (RemL-C) is closely associated with very-low-density lipoprotein remnants: comparison with the immunoseparation assay.

BACKGROUND: Remnant-like particle-cholesterol (RLP-C) is recognized as a risk factor for cardiovascular disease. As an alternative to the immunoseparation assay widely used for the measurement of RLP-C, a new remnant lipoprotein-C homogenous assay (RemL-C) is available. In light of its homogeneity as an assay method, we speculated that this homogeneous assay (RemL-C) is closely associated with very-low-density lipoprotein(VLDL) remnant including intermediate-density lipoprotein(IDL). We examined the characteristics of the homogeneous assay for reacting with VLDL remnants. METHODS AND RESULTS: VLDL1, VLDL2, and IDL were separated by ultracentrifugation in the fasting serum of subjects including hypertriglyceridemia and uremic patients usually having higher levels of remnants. While RemL-C and RLP-C were mainly recovered in VLDL1 and both assays were strongly correlated with serum TG and VLDL1, the RemL-C assay was more closely correlated with VLDL2 and IDL levels than the RLP-C assay. RemL-C levels were significantly correlated with IDL-C, whereas RLP-C levels had only borderline associations with IDL-C (r= 0.56 Vs. 0.31). CONCLUSIONS: The remnant lipoprotein cholesterol homogenous assay is more closely associated with VLDL2 and IDL than the immunoseparation assay.