McMaster University, Juravinski Hospital and Cancer Centre, 711 Concession Street Hamilton, L8V 1C3 ON, Canada.
Core Laboratory, Hamilton Health Sciences, Hamilton, ON, Canada.
Clin Chem Lab Med. 2018 Jun 27;56(7):1176-1181. doi: 10.1515/cclm-2017-1122.
Analytical evaluation of high-sensitivity cardiac troponin (hs-cTn) assays, with particular attention to imprecision, interferences and matrix effects, at normal cTn concentrations, is of utmost importance as many different clinical algorithms use concentration cutoffs <10 ng/L for decision-making. The objective for the present analytical study was to compare the new Beckman Coulter hs-cTnI assay (Access hsTnI) to Abbott's hs-cTnI assay in different matrices and for different interferences, with a focus on concentrations <10 ng/L.
The limit of blank (LoB) and the limit of detection (LoD) were determined in different matrices for the Beckman hs-cTnI assay. Passing-Bablok regression and difference plots were determined for 200 matched lithium heparin and EDTA plasma samples for the Beckman assay and 200 lithium heparin samples for the Abbott assay. Both EDTA and heparin plasma samples were also evaluated for stability under refrigerated conditions, for endogenous alkaline phosphatase interference and for hemolysis and icterus.
The Beckman hs-cTnI assay LoB was 0.5 ng/L with the following range of LoDs=0.8-1.2 ng/L, with EDTA plasma yielding lower concentrations as compared to lithium heparin plasma (mean difference=-14.9%; 95% CI=-16.9 to 12.9). Below 10 ng/L, lithium heparin cTnI results from the Beckman assay were on average 1.1 ng/L (95% CI=0.7 to 1.5) higher than the Abbott results, with no difference between the methods when using EDTA plasma (mean difference =-0.1 ng/L; 95% CI=-0.3 to 0.2). Low cTnI concentrations were less effected by interferences in EDTA plasma.
The Access hsTnI method can reliably detect normal cTnI concentrations with both lithium heparin and EDTA plasma being suitable matrices.
在正常 cTn 浓度下，对高敏心肌肌钙蛋白（hs-cTn）分析物进行分析评估，特别是对不精密度、干扰和基质效应的评估非常重要，因为许多不同的临床算法使用浓度截断值 <10ng/L 进行决策。本分析研究的目的是比较贝克曼库尔特 hs-cTnI 测定法（Access hsTnI）与 Abbott 的 hs-cTnI 测定法在不同基质中的差异和干扰情况，重点关注浓度 <10ng/L 的情况。
在不同基质中确定贝克曼 hs-cTnI 测定法的空白限（LoB）和检测限（LoD）。为贝克曼测定法的 200 对匹配的锂肝素和 EDTA 血浆样本以及 Abbott 测定法的 200 个锂肝素样本确定了通过-Bablok 回归和差值图。还评估了 EDTA 和肝素血浆样本在冷藏条件下的稳定性、内源性碱性磷酸酶干扰以及溶血和黄疸情况。
贝克曼 hs-cTnI 测定法的 LoB 为 0.5ng/L，LoD 范围为 0.8-1.2ng/L，与锂肝素血浆相比，EDTA 血浆产生的浓度较低（平均差值=-14.9%；95%置信区间=-16.9 至 12.9）。在 10ng/L 以下，贝克曼测定法的锂肝素 cTnI 结果平均比 Abbott 结果高 1.1ng/L（95%置信区间=0.7 至 1.5），而使用 EDTA 血浆时两种方法之间没有差异（平均差值=-0.1ng/L；95%置信区间=-0.3 至 0.2）。低 cTnI 浓度在 EDTA 血浆中受干扰的影响较小。
Access hsTnI 方法可以可靠地检测出锂肝素和 EDTA 血浆中的正常 cTnI 浓度，这两种基质都适用。
