[Development of homogeneous assay for HDL-C in serum]

Recent development of several homogeneous assays for measuring HDL-cholesterol (HDL-C) in serum without pretreatment has been reviewed. Several problems on the five homogeneous assays based on PEG-modified enzyme/alpha-cyclodextrin sulfate (PEGME), polyanion-polymer/detergent (PPD), immunoinhibition, catalase/detergent and 4-sulfonyl calyx[8]areine are discussed comparing with CDC reference method. The two homogeneous assays (PEGME and PPD) used in many laboratories were precise and correlated well with CDC reference method (mean percentage bias: < 5%). The discrepancies of recoveries for apo E-rich HDL-C were observed among reagents of homogeneous assays in serum from patients with hepatobiliary diseases and cholesterol ester transfer protein (CETP) deficiency. Apo E-rich HDL slightly contained in normal serum was most recovered by homogeneous methods, but not by precipitation methods. The differences between the normal values for HDL-C obtained by homogeneous assay (PEGME method) and precipitation method (dextran sulfate-phosphotungstate-MgCl2) were statistically significant (p < 0.01).