High-density lipoproteins reference methods

Hahoran P, Roetering H, Pisani T, van den Berg B, Cobbaert C. Reference standardization and analytical performance of a liquid homogeneous high-density lipoprotein cholesterol method compared with chemical precipitation method. Arch Pathol Lab Med 1999 123 317-26. 

Table 1 Metrological properties of methods used by the Choles- CV coefficient of variation, HDLC high-density lipoprotein cho-terol Reference Method Laboratory Network (CKMLN). 2 KM lesterol, SD standard deviation, LDLC low-density lipoprotein Secondary reference method, DCM designated comparison meth- cholesterol, NA not available od, IDMS isotope dilution mass spectroscopy, AK Abell-Kendall,...

Harris N, Galpchian V, Rifai N. Three routine methods for measuring high-density lipoprotein cholesterol compared with the Reference Method. 

Lipoproteins produced in the liver take one of two forms. Low-density lipoproteins (LDL) carry cholesterol directly to cells. Because this cholesterol serves a useful biological function, it is sometimes called good cholesterol. High-density lipoproteins (HDL), by contrast, bypass cells and remain in the blood stream. The cholesterol in HDL lipoproteins serves no useful function in the body and is often referred to as bad cholesterol. The role of cholesterol in the human body and dietary methods of maintaining the correct HDL LDL ratio in the blood has been the subject of some controversy and considerable educational programs in recent decades. 

For the convenience of the reader, we have outlined the method of sequential flotation employed in our laboratory for separating chylomicrons VLDL, LDL, HDLa, HDLs, VHDL, and d> 1.25 bottom (Table 1). This method, the result of years of experience, has been highly reproducible in terms of the normal human population examined in this laboratory. Such a method may not necessarily apply to dyslipoproteinemic states, where modifications may be necessary, depending on the type of abnormality under consideration. It should also be stressed that any lipoprotein isolated is in need of purification this may be achieved by ultracentrifugation based on the assumption that contaminants are in loose association with the main complex. Whenever this purification is not achieved, other methods may be used as outlined below. For a discussion of the application of density gradient ultracentrifugation to the study of plasma lipoproteins, the reader is referred to a recent review (L3). 

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