[Plasma determination of homocysteine on CPC Immulite 2000: comparison with determination on IMX Abbott]

Plasma total homocysteine is a parameter frequently included in the biological investigation of arterious or venous thrombotic diseases. Different techniques, chromatographic, enzymatic, and immunochemical, are used in the measurement of homocysteine. Among immunochemical methods, some are conceived to function on multiparametric automates, leading to a greater accessibility of the test for most of the clinical laboratories. In this study, we have evaluated a new immunoassay proposed by the DPC Company for the Immulite 2000 analyzer (chemiluminescence) and compared its performance against the Abbott's immunoassay on IMx (fluorescence polarization). The results obtained show very good general performance of the DPC's technique. Linearity is also excellent. The within run CVs are 9.9, 7.0 and 5.4% and the between run CVs are 8.2, 3.9 and 4.3% respectively for homocysteine levels of 4.2, 13.9 and 27.7 pmol/L. We found a very good correlation between DPC's and Abbott's methods (regression analysis:y=0.948 x + 0.05; r=0.895). The mean of differences between both methods is -0.55 micromol/L. On the whole, the DPC technique appeared in our experience as easily exchangeable, from the analytical point of view, with Abbott's technique.