Automated determination of apolipoproteins A-I and B with an improved immunoturbidimetric assay using Boehringer Mannheim and Hitachi analyzer systems

Results from an evaluation of immunoturbidimetric methods (Tina-quant) for apolipoprotein A-I (apo AI) and apolipoprotein B (apo B), are presented and compared with results from six other commercial immunoassays. These apo AI and B procedures are fully automated on the Boehringer Mannheim (BM) and Hitachi 704 and 717 analyzers and use undiluted serum. The methods provide an analytical range from 0.002 to 2.3 g/L for apo AI and from 0.003 to 2.2 g/L for apo B and are precise with maximal CVs of 4%. Neither hemoglobin nor intralipid interfered with the assays. Bilirubin concentrations higher than 376 mumol/L for apo AI and 444 mumol/L for apo B, produce a negative interference. In the apo AI method a positive interference caused by rheumatoid factor was found for concentrations higher than 440 x 10(3) IU/L. All comparisons showed an excellent correlation (r > 0.93) with all methods, and slopes ranged from 1.01 to 1.25 for apo AI, and from 0.62 to 1.15 for apo B.