Blennow Kaj, Stomrud Erik, Zetterberg Henrik, Borlinghaus Niels, Corradini Veronika, Manuilova Ekaterina, Müller-Hübner Laura, Quevenco Frances-Catherine, Rutz Sandra, Hansson Oskar
Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.
Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.
Clin Chem Lab Med. 2022 Oct 24;61(2):234-244. doi: 10.1515/cclm-2022-0516. Print 2023 Jan 27.
Timely diagnosis of Alzheimer's disease (AD) is critical for appropriate treatment/patient management. Cerebrospinal fluid (CSF) biomarker analysis is often used to aid diagnosis. We assessed analytical performance of second-generation (Gen II) Elecsys CSF immunoassays (Roche Diagnostics International Ltd), and adjusted existing cut-offs, to evaluate their potential utility in clinical routine.
Analytical performance was assessed using CSF samples measured with Elecsys CSF Gen II immunoassays on cobas e analyzers. Aβ42 Gen I/Gen II immunoassay method comparisons were performed (Passing-Bablok regression). Cut-off values were adjusted using estimated bias in biomarker levels between BioFINDER protocol aliquots/Gen I immunoassays and Gen II protocol aliquots/immunoassays. Distribution of Gen II immunoassay values was evaluated in AD, mild cognitive impairment (MCI), and cognitively normal cohorts; percentage observations outside the measuring range were derived.
The Gen II immunoassays demonstrated good analytical performance, including repeatability, intermediate precision, lot-to-lot agreement (Pearson's r: ≥0.999), and platform agreement (Pearson's r: ≥0.995). Aβ42 Gen I/Gen II immunoassay measurements were strongly correlated (Pearson's r: 0.985-0.999). Aβ42 Gen II immunoassay cut-offs were adjusted to 1,030 and 800 ng/L, and pTau181/Aβ42 ratio cut-offs to 0.023 and 0.029, for Gen II and I protocols, respectively. No observations were below the lower limit of the measuring range; above the upper limit, there were none from the AD cohort, and 2.6 and 6.8% from the MCI and cognitively normal cohorts, respectively.
Our findings suggest that the Gen II immunoassays have potential utility in clinical routine to aid diagnosis of AD.
阿尔茨海默病（AD）的及时诊断对于恰当的治疗/患者管理至关重要。脑脊液（CSF）生物标志物分析常被用于辅助诊断。我们评估了第二代（Gen II）Elecsys脑脊液免疫分析（罗氏诊断国际有限公司）的分析性能，并调整了现有的临界值，以评估其在临床常规中的潜在效用。
使用在cobas e分析仪上用Elecsys脑脊液Gen II免疫分析测量的脑脊液样本评估分析性能。进行了Aβ42第一代/第二代免疫分析方法比较（Passing-Bablok回归）。使用BioFINDER方案等分试样/第一代免疫分析与第二代方案等分试样/免疫分析之间生物标志物水平的估计偏差来调整临界值。在AD、轻度认知障碍（MCI）和认知正常队列中评估第二代免疫分析值的分布；得出测量范围之外的观察值百分比。
第二代免疫分析显示出良好的分析性能，包括重复性、中间精密度、批次间一致性（Pearson相关系数r：≥0.999）和平台一致性（Pearson相关系数r：≥0.995）。Aβ42第一代/第二代免疫分析测量结果高度相关（Pearson相关系数r：0.985 - 0.999）。第二代免疫分析中，Aβ42的临界值分别调整为1030和800 ng/L，pTau181/Aβ42比值的临界值分别调整为0.023和0.029，用于第二代和第一代方案。没有观察值低于测量范围下限；高于上限的情况，AD队列中没有，MCI和认知正常队列中分别为2.6%和6.8%。
我们的研究结果表明，第二代免疫分析在临床常规中辅助AD诊断具有潜在效用。
