De Stefano Alessandro, Mannucci Liliana, Massoud Renato, Bernardini Sergio, Cortese Claudio
Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.
Biochem Med (Zagreb). 2017 Oct 15;27(3):030701. doi: 10.11613/BM.2017.030701. Epub 2017 Aug 28.
Lipoprotein-associated phospholipase A2 (Lp-PLA) is a marker of vascular inflammation associated with coronary heart disease and stroke. We evaluated analytical performance of the PLAC® Activity Test on Siemens Dimension Vista® 1500 analyzer and measured Lp-PLA activity in Italian adults to establish reference intervals (RIs) and evaluate correlation with circulating lipids and age.
The evaluation protocol consisted of precision, linearity, sensitivity, method comparison, substrate depletion ("hook") effect and interference assessment. Inhibitor (Darapladib) effect was also evaluated. Lp-PLA activity was measured in 250 healthy donors (123 males, 127 females, aged 18-70 years). Central 95% RIs were established using nonparametric statistics.
Intra-assay and inter-assay precision showed CVs of 0.6% - 1.4% and 0.9% - 2.0%, respectively. Linearity replicates showed R > 0.98. Limit of quantitation was 5.8 U/L (CV = 9.4%). Bland Altman plot showed bias - 0.9, 95% limits of agreement -6.5 - 4.72. Passing-Bablok regression showed excellent correlation (Slope = 1.02, 95% CI: 1.01 to 1.03; Intercept = - 1.86, 95% CI: - 3.08 to - 1.26; R = 0.999). No "hook effect" was observed at Lp-PLA activities ≤ 1000 U/L. Average Lp-PLA activity in 250 healthy donors was 182 ± 44 U/L (mean ± SD). Males showed statistically significant higher activities than females (P < 0.001). RIs were 107 - 265 U/L for males and 84 - 225 U/L for females. Moderate significant correlation (r = 0.29, P < 0.001) was found between Lp-PLA activity and total cholesterol.
The PLAC® Activity Test shows very good performance characteristics on Dimension Vista® 1500.
脂蛋白相关磷脂酶A2（Lp-PLA）是一种与冠心病和中风相关的血管炎症标志物。我们评估了西门子Dimension Vista® 1500分析仪上PLAC®活性检测的分析性能，并测定了意大利成年人的Lp-PLA活性，以建立参考区间（RI）并评估其与循环脂质及年龄的相关性。
评估方案包括精密度、线性、灵敏度、方法比较、底物耗竭（“钩状”）效应和干扰评估。还评估了抑制剂（达拉匹林）的效应。对250名健康供者（123名男性，127名女性，年龄18 - 70岁）进行了Lp-PLA活性检测。使用非参数统计方法建立了中心95%参考区间。
批内和批间精密度分别显示变异系数（CV）为0.6% - 1.4%和0.9% - 2.0%。线性重复实验显示R > 0.98。定量限为5.8 U/L（CV = 9.4%）。Bland Altman图显示偏差为 - 0.9，95%一致性界限为 - 6.5至4.72。Passing-Bablok回归显示具有良好的相关性（斜率 = 1.02，95%置信区间：1.01至1.03；截距 = - 1.86，95%置信区间： - 3.08至 - 1.26；R = 0.999）。在Lp-PLA活性≤1000 U/L时未观察到“钩状效应”。250名健康供者的平均Lp-PLA活性为182±44 U/L（均值±标准差）。男性的活性在统计学上显著高于女性（P < 0.001）。男性的参考区间为107 - 265 U/L，女性为84 - 225 U/L。发现Lp-PLA活性与总胆固醇之间存在中度显著相关性（r = 0.29，P < 0.001）。
PLAC®活性检测在Dimension Vista® 1500上显示出非常好的性能特征。
