Haltmayer Meinhard, Mueller Thomas, Gegenhuber Alfons, Poelz Werner
Department of Laboratory Medicine, Konventhospital Barmherzige Brueder, Linz, Austria.
Clin Lab. 2004;50(3-4):175-80.
A new fully automated chemiluminescence assay for total homocysteine (tHcy) determination (ADVIA Centaur homocysteine, Bayer) was evaluated in comparison with a previously established fluorescence polarization assay (AxSYM homocysteine, Abbott). Linearity could be demonstrated in a concentration range up to 50 micromol/l for both methods. The detection limit was 0.92 micromol/l for the AxSYM and 0.61 micromol/l for the ADVIA Centaur analyzer. Within-run coefficients of variation (%CV) ranged from 1.7% to 1.8% for the AxSYM, and from 2.2% to 2.7% for the ADVIA Centaur analyzer, total CV ranged from 2.5% to 3.5% for the AxSYM, and from 3.6% to 4.5% for the ADVIA Centaur analyzer. Passing and Bablock regression analysis of 180 samples with the AxSYM assay as reference method revealed an intercept of -0.41 micromol/l (95% CI -1.17 to 0.20 micromol/l) and a slope of 1.11 (95% CI 1.05 to 1.18), the Bland-Altman difference plot showed a mean difference of -0.9 micromol/l between tHcy measurements with wide 95% limits of agreement (-3.6 to 1.7 micromol/l). At thresholds of 10 and 15 micromol/l there was a considerable proportion of discordant classifications of study subjects by the AxSYM and ADVIA Centaur method. When evaluating case-control status for vascular disease both assays showed similar characteristics (i.e., significant difference of tHcy in 71 CAD patients and 109 control subjects, and non-significant odds ratios for tHcy in the multivariate model). In conclusion, both methods are reliable for routine tHcy determination in clinical laboratories, as they are fast and completely automated systems with good accuracy and precision allowing sample random access, automatic dilution and stored calibration capabilities. However, results of both assays may not be used interchangeably since the ADVIA Centaur method tends to overestimate tHcy values compared to the AxSYM method.
我们对一种用于测定总同型半胱氨酸（tHcy）的新型全自动化学发光测定法（ADVIA Centaur同型半胱氨酸检测法，拜耳公司）进行了评估，并与先前建立的荧光偏振测定法（AxSYM同型半胱氨酸检测法，雅培公司）进行了比较。两种方法在高达50微摩尔/升的浓度范围内均显示出线性关系。AxSYM的检测限为0.92微摩尔/升，ADVIA Centaur分析仪的检测限为0.61微摩尔/升。AxSYM的批内变异系数（%CV）范围为1.7%至1.8%，ADVIA Centaur分析仪的批内变异系数范围为2.2%至2.7%；AxSYM的总变异系数范围为2.5%至3.5%，ADVIA Centaur分析仪的总变异系数范围为3.6%至4.5%。以AxSYM检测法为参考方法，对180个样本进行的Passing和Bablock回归分析显示，截距为-0.41微摩尔/升（95%CI为-1.17至0.20微摩尔/升），斜率为1.11（95%CI为1.05至1.18），Bland-Altman差异图显示，tHcy测量值之间的平均差异为-0.9微摩尔/升，95%一致性界限较宽（-3.6至1.7微摩尔/升）。在10和15微摩尔/升的阈值下，AxSYM和ADVIA Centaur方法对研究对象的分类存在相当比例的不一致。在评估血管疾病的病例对照状态时，两种检测方法显示出相似的特征（即，71例CAD患者和109例对照受试者的tHcy有显著差异，多变量模型中tHcy的优势比无显著差异）。总之，两种方法对于临床实验室常规tHcy测定都是可靠的，因为它们是快速且完全自动化的系统，具有良好的准确性和精密度，允许样本随机进样、自动稀释和储存校准功能。然而，两种检测方法的结果可能不能互换使用，因为与AxSYM方法相比，ADVIA Centaur方法倾向于高估tHcy值。
