Evaluation of the AxSYM Homocysteine Assay and Comparison with the IMx Homocysteine Assay

Increased plasma total homocysteine (tHcy), a sulfur amino acid, is an important risk factor for vascular disease (1) and for arterial and venous thromboembolism (2). Several techniques have been developed to measure plasma or serum tHcy concentrations (3). Given the extension of this determination to routine clinical chemistry laboratories, an immunoassay has been developed for use with the AxSYM analyzer (4). The AxSYM is a completely automated system, which allows immediate and continuous access. We evaluated the analytical performance of the automated AxSYM assay and compared it with the IMx Hcy assay (5), a method widely used for tHcy determination in laboratories. Both methods use reduction of protein-bound Hcy by dithiothreitol, conversion of Hcy to S -adenosylhomocysteine in the presence of adenosine catalyzed by hydrolase …