Dakterzada Farida, López-Ortega Ricard, Arias Alfonso, Riba-Llena Iolanda, Ruiz-Julián Maria, Huerto Raquel, Tahan Nuria, Piñol-Ripoll Gerard
Cognitive Disorders Unit, Clinical Neuroscience Research Group, Santa Maria University Hospital, IRBLleida, Lleida, Spain.
Front Aging Neurosci. 2021 Mar 4;13:604119. doi: 10.3389/fnagi.2021.604119. eCollection 2021.
Manual ELISA assays are the most commonly used methods for quantification of biomarkers; however, they often show inter- and intra-laboratory variability that limits their wide use. Here, we compared the Innotest ELISA method with two fully automated platforms (Lumipulse and Elecsys) to determine whether these new methods can provide effective substitutes for ELISA assays. We included 149 patients with AD ( = 34), MCI ( = 94) and non-AD dementias ( = 21). Aβ42, T-tau, and P-tau were quantified using the ELISA method (Innotest, Fujirebio Europe), CLEIA method on a Lumipulse G600II (Fujirebio Diagnostics), and ECLIA method on a Cobas e 601 (Roche Diagnostics) instrument. We found a high correlation between the three methods, although there were systematic differences between biomarker values measured by each method. Both Lumipulse and Elecsys methods were highly concordant with clinical diagnoses, and the combination of Lumipulse Aβ42 and P-tau had the highest discriminating power (AUC 0.915, 95% CI 0.822-1.000). We also assessed the agreement of AT(N) classification for each method with AD diagnosis. Although differences were not significant, the use of Aβ42/Aβ40 ratio instead of Aβ42 alone in AT(N) classification enhanced the diagnostic accuracy (AUC 0.798, 95% CI 0.649-0.947 vs. AUC 0.778, 95% CI 0.617-0.939). We determined the cut-offs for the Lumipulse and Elecsys assays based on the Aβ42/Aβ40 ratio ± status as a marker of amyloid pathology, and these cut-offs were consistent with those recommended by manufacturers, which had been determined based on visual amyloid PET imaging or diagnostic accuracy. Finally, the biomarker ratios (P-tau/Aβ42 and T-tau/Aβ42) were more consistent with the Aβ42/Aβ40 ratio for both Lumipulse and Elecsys methods, and Elecsys P-tau/Aβ42 had the highest consistency with amyloid pathology (AUC 0.994, 95% CI 0.986-1.000 and OPA 96.4%) at the ≥0.024 cut-off. The Lumipulse and Elecsys cerebrospinal fluid (CSF) AD assays showed high analytical and clinical performances. As both automated platforms were standardized for reference samples, their use is recommended for the measurement of CSF AD biomarkers compared with unstandardized manual methods, such as Innotest ELISA, that have demonstrated a high inter and intra-laboratory variability.
手动酶联免疫吸附测定（ELISA）是用于生物标志物定量的最常用方法；然而，它们常常表现出实验室间和实验室内的变异性，这限制了它们的广泛应用。在此，我们将Innotest ELISA方法与两个全自动平台（Lumipulse和Elecsys）进行比较，以确定这些新方法是否能够有效替代ELISA测定。我们纳入了149例阿尔茨海默病（AD）患者（n = 34）、轻度认知障碍（MCI）患者（n = 94）和非AD痴呆患者（n = 21）。使用ELISA方法（Innotest，Fujirebio Europe）、Lumipulse G600II上的化学发光酶免疫分析（CLEIA）方法（Fujirebio Diagnostics）以及Cobas e 601（Roche Diagnostics）仪器上的电化学发光免疫分析（ECLIA）方法对β淀粉样蛋白42（Aβ42）、总tau蛋白（T-tau）和磷酸化tau蛋白（P-tau）进行定量。我们发现这三种方法之间具有高度相关性，尽管每种方法测得的生物标志物值存在系统性差异。Lumipulse和Elecsys方法与临床诊断均高度一致，且Lumipulse Aβ42和P-tau的组合具有最高的鉴别能力（曲线下面积[AUC] 0.915，95%置信区间[CI] 0.822 - 1.000）。我们还评估了每种方法的AT(N)分类与AD诊断的一致性。尽管差异不显著，但在AT(N)分类中使用Aβ42/Aβ40比值而非单独的Aβ42可提高诊断准确性（AUC 0.798，95% CI 0.649 - 0.947对比AUC 0.778，95% CI 0.617 - 0.939）。我们基于Aβ42/Aβ40比值±状态作为淀粉样蛋白病理学标志物来确定Lumipulse和Elecsys测定的临界值，这些临界值与制造商推荐的一致，制造商是基于视觉淀粉样蛋白正电子发射断层扫描（PET）成像或诊断准确性来确定的。最后，对于Lumipulse和Elecsys方法，生物标志物比值（P-tau/Aβ42和T-tau/Aβ42）与Aβ42/Aβ40比值更为一致，且在≥0.024的临界值下，Elecsys P-tau/Aβ42与淀粉样蛋白病理学具有最高的一致性（AUC 0.994，95% CI 0.986 - 1.000和百分一致性[OPA] 96.4%）。Lumipulse和Elecsys脑脊液（CSF）AD测定显示出较高的分析性能和临床性能。由于两个全自动平台均针对参考样本进行了标准化，因此与未标准化的手动方法（如Innotest ELISA，已证明具有较高的实验室间和实验室内变异性）相比，推荐使用它们来测量CSF AD生物标志物。
