Homocysteine measurement by Vitros® Microtip homocysteine assay
Homocysteine measurement by Vitros® Microtip homocysteine assay
复制标题
DOI：
10.1515/cclm.2008.054
复制
发表时间：
2008-01-01
影响因子：
6.8
通讯作者：
Gerlo, Erik
中科院分区：
文献类型：
--
作者：
Martens, Geert A.;De Nayer, Joeri;Gerlo, Erik
背景：循环总同型半胱氨酸升高是一个独立的血管危险因素。酶促同型半胱氨酸测定是高效液相或免疫化学分析的替代方法，适用于自动化检测。在这里，我们报告了用于Vitros(R)自动分析仪的基于商业半胱氨酸β-合成酶的分析性能。方法：通过重复测量同型半胱氨酸标准溶液(1-65mU/L)，推导出线性范围、检出限和分析灵敏度。使用NCCLS EP5-A2商业对照和NIST-SRM1955参考材料的准确性进行不精密度评估。结果：同型半胱氨酸在1~90mU/L范围内呈良好的线性关系。在同型半胱氨酸9.7~43.2 mU/L范围内，日内总不精密度为4.5(3.9)%~2.8(1.6)%；同型半胱氨酸浓度为8.9和17.7 mU/L时，准确度较好，偏差分别为+6.4%和-1.2%，而在4.0 mU/L时有显著负偏差(-20.1%)。酶促方法的灵敏度略低于高效液相色谱法(检出限分别为0.7mU/L和0.2mU/L)，但与后者相关性良好(r(2)=0.9997，斜率=1.04，截距=-0.66mU/L)，且精密度更高(p=9mU/L)。
Background: Elevated circulating total homocysteine is an independent vascular risk factor. Enzymatic homocysteine measurements represent an alternative to HPLC- or immunochemistry-based assays, suitable for automation. Here, we report on analytical performance of a commercial cystathionine beta-synthasebased assay, for use on Vitros (R) automated analyzers.Methods: Linear range, limit of detection and analytical sensitivity were inferred from duplicate measurements of homocystine standard solutions (1-65 mu mol/L). Imprecision was assessed using commercial controls according to NCCLS EP5-A2 and accuracy using NIST-SRM1955 reference material. Agreement with a clinically validated HPLC method was examined on 207 patient samples.Results: The enzymatic assay was linear from 1 to 90 mu mol/L homocysteine. Total (within-day) imprecision ranged from 4.5 (3.9)% to 2.8 (1.6)% at homocysteine 9.7-43.2 mu mol/L. Accuracy was acceptable at 8.9 and 17.7 mu mol/L homocysteine, with +6.4% and -1.2% bias, respectively, but showed substantial negative bias (-20.1%) at 4.0 mu mol/L. High triglycerides (19.8 mu mol/L) negatively interfered. The enzymatic method was slightly less sensitive than the HPLC method (limit of detection 0.7 and 0.2 mu mol/L, respectively) but correlated well with the latter (r(2) =0.9997, slope=1.04, intercept=-0.66 mu mol/L) and was more precise (p= 9 mu mol/L. Its analytical performance and suitability for automation make the Vitros (R) assay an analytically acceptable alternative to HPLC-based methods.