THE RELATIVE USEFULNESS OF AUTOMATED APOLIPOPROTEIN-A-I AND HIGH-DENSITY-LIPOPROTEIN CHOLESTEROL ASSAYS AS MARKERS FOR CORONARY-ARTERY DISEASE

Research studies have shown that apolipoprotein A-I (ape A-I) is a bet ter marker for coronary artery disease (CAD) than high-density lipopro tein cholesterol (HDLC). Yet, it is unclear whether assays for apolipo protein A-I, which is part of macromolecular lipoprotein complex, can perform as well when measured by routine automated clinical laboratory techniques. The purpose of this study was to compare automated apolip oprotein A-I assays with HDLC as a marker for CAD. The authors studied two groups of of angiographically documented men, aged 44-70 years, 4 2 with CAD and 123 without CAD in an unmatched, controlled study. Stan dard clinical laboratory techniques for assaying HDLC, and automated k it rate immunonephelometric, end point immunonephelometric, end immuno turbidimetric assays for apolipoprotein A-I were used. High-density li poprotein cholesterol was a better marker than apolipoprotein A-I, acc ording to the Mann Whitney test; HDLC also showed better diagnostic se nsitivity, specificity, and predictive value. Using a precipitation me thod, HDL(3) was a better marker than HDL(2), but not as good as total HDLC. The authors concluded that HDLC remains the best routine single CAD marker commonly available for evaluation of HDL status in a high- risk population.