[Standardization of the immunochemical detection of apolipoprotein A-I and B]

Apolipoprotein A-I, the major protein of high-density lipoproteins, and apolipoprotein B, the major protein of low-density lipoproteins can serve as important predictor of the risk of cardiovascular diseases. The lack of an internationally valid standardization is a serious impediment to a broad application of the apolipoprotein measurements in the laboratory diagnosis of atherosclerosis. A common effort is at the present made by the IFCC Committee on Apolipoproteins together with several commercial organizations to achieve a consensus on a practical standardization procedure for the measurement of apolipoprotein A-I and B. The aim is a) to calibrate all commercially available Apo A-I and Apo B test kits using frozen serum pools previously standardized against primary reference materials and b) to select the secondary serum reference preparations which will substitute the frozen serum pools and will be used for the control of the validity of the own calibration. The available results from a preliminary exercise prove with a variation less than 5% for Apo A-I and less than 8% for Apo B with patients' samples that the use of common reference materials leads to the harmonization of the results obtained with different test systems for measurement of apolipoprotein A-I and B.