Dittadi Ruggero, Matteucci Mara, Meneghetti Elisa, Ndreu Rudina
U.O.C. Laboratorio Analisi, Laboratory Medicine Department, Ospedale dell'Angelo, ULSS 3 Serenissima, Mestre, Italy.
Eureka srl - Lab Division, Chiaravalle (AN), Italy.
J Clin Lab Anal. 2018 Mar;32(3). doi: 10.1002/jcla.22286. Epub 2017 Jun 23.
To reassess the imprecision and Limit of Quantitation, to evaluate the cross-reaction with dehydroepiandrosterone-sulfate (DHEAS), the accuracy toward liquid chromatography-mass spectrometry (LC-MS) and the reference interval of the Access Testosterone method, performed by DxI immunoassay platform (Beckman Coulter).
Imprecision was evaluated testing six pool samples assayed in 20 different run using two reagents lots. The cross-reaction with DHEAS was studied both by a displacement curve and by spiking DHEAS standard in two serum samples with known amount of testosterone. The comparison with LC-MS was evaluated by Passing-Bablock analysis in 21 routine serum samples and 19 control samples from an External Quality Assurance (EQA) scheme. The reference interval was verified by an indirect estimation on 2445 male and 2838 female outpatients.
The imprecision study showed a coefficient of variation (CV) between 2.7% and 34.7% for serum pools from 16.3 and 0.27 nmol/L. The value of Limit of Quantitation at 20% CV was 0.53 nmol/L. The DHEAS showed a cross-reaction of 0.0074%. A comparison with LC-MS showed a trend toward a slight underestimation of immunoassay vs LC-MS (Passing-Bablock equations: DxI=-0.24+0.906 LCMS in serum samples and DxI=-0.299+0.981 LCMS in EQA samples). The verification of reference interval showed a 2.5th-97.5th percentile distribution of 6.6-24.3 nmol/L for male over 14 years and <0.5-2.78 nmol/L for female subjects, in accord with the reference intervals reported by the manufacturer.
The Access Testosterone method could be considered an adequately reliable tool for the testosterone measurement.
重新评估不精密度和定量限，评估与硫酸脱氢表雄酮（DHEAS）的交叉反应、相对于液相色谱 - 质谱联用仪（LC - MS）的准确性以及由DxI免疫分析平台（贝克曼库尔特公司）执行的Access睾酮检测方法的参考区间。
通过使用两个试剂批次在20次不同运行中检测6个混合样本评估不精密度。通过置换曲线以及在两个已知睾酮含量的血清样本中加入DHEAS标准品来研究与DHEAS的交叉反应。通过对21份常规血清样本和来自外部质量保证（EQA）计划的19份对照样本进行Passing - Bablock分析来评估与LC - MS的比较。通过对2445名男性和2838名女性门诊患者进行间接估计来验证参考区间。
不精密度研究表明，对于浓度为16.3和0.27 nmol/L的血清混合样本，变异系数（CV）在2.7%至34.7%之间。20% CV时的定量限为0.53 nmol/L。DHEAS显示交叉反应为0.0074%。与LC - MS的比较表明，免疫分析相对于LC - MS有轻微低估的趋势（Passing - Bablock方程：血清样本中DxI = -0.24 + 0.906 LCMS，EQA样本中DxI = -0.299 + 0.981 LCMS）。参考区间验证显示，14岁以上男性的第2.5至97.5百分位数分布为6.6 - 24.3 nmol/L，女性受试者为<0.5 - 2.78 nmol/L，与制造商报告的参考区间一致。
Access睾酮检测方法可被视为用于睾酮测量的足够可靠的工具。
