H-1 NMR-BASED ABSOLUTE QUANTITATION OF HUMAN LIPOPROTEINS AND THEIR LIPID CONTENTS DIRECTLY FROM PLASMA

A new method is presented for absolute quantitation of lipid and prote in contents of human lipoproteins directly from plasma. The method ena bles complete lipoprotein lipid profiles to be obtained in a total tim e of less than one hour. Absolute concentrations of triglycerides, pho spholipids, total cholesterol, free cholesterol, esterified cholestero l, total proteins, and total masses can be estimated for the very low density (VLDL) and low density (LDL) lipoprotein fractions. For the hi gh density lipoprotein (HDL) fraction all components except triglyceri des can be quantitated. The method is a combination of H-1 NMR spectro scopy and a sophisticated lineshape fitting analysis technique. In thi s paper we present the calibration of the method using 15 plasma sampl es followed by a double-blind test of 51 plasma samples from 43 indivi duals. In total, 66 plasma samples were analyzed. Comparison of the H- 1 NMR-based results with the data of the biochemical assays showed exc ellent agreement; the correlation coefficient for VLDL triglycerides w as 0.98, for LDL cholesterol 0.88, and for HDL cholesterol 0.93. This method can be directly integrated to many kinds of biomedical NMR stud ies to offer additional biochemically important quantitative lipoprote in information, the measurement of which is usually too laborious by c onventional biochemical methods and too high-priced to be adapted into the study protocols. Moreover, the method also has considerable poten tial to be developed for a routine clinical assay.