Karikari Thomas, Chen Yijun, Zeng Xuemei, Olvera-Rojas Marcos, Sehrawat Anuradha, Lafferty Tara, Pascoal Tharick, Villemagne Victor, Solis-Urra Patricio, Triviño-Ibañez Eva, Gómez-Rí Manuel, Cohen Ann, Ikonomovic Milos, Esteban-Cornejo Irene, Erickson Kirk, Lopez Oscar, Yates Nathan
University of Pittsburgh.
University of Granada.
Res Sq. 2024 Sep 2:rs.3.rs-4947448. doi: 10.21203/rs.3.rs-4947448/v1.
High-performance, resource-efficient methods for plasma amyloid-β (Aβ) quantification in Alzheimer's disease are lacking; existing mass spectrometry-based assays are resource- and time-intensive. We developed a streamlined mass spectrometry method with a single immunoprecipitation step, an optimized buffer system, and ≤75% less antibody requirement. Analytical and clinical performances were compared with an in-house reproduced version of a well-known two-step assay. The streamlined assay showed high dilution linearity (r>0.99) and precision (< 10% coefficient of variation), low quantification limits (Aβ1-40: 12.5 pg/ml; Aβ1-42: 3.125 pg/ml), and high signal correlation (r~0.7) with the two-step immunoprecipitation assay. The novel single-step assay showed more efficient recovery of Aβ peptides via fewer immunoprecipitation steps, with significantly higher signal-to-noise ratios, even at plasma sample volumes down to 50 pl. Both assays had equivalent performances in distinguishing non-elevated vs. elevated brain Aβ-PET individuals. The new method enables simplified yet robust evaluation of plasma Aβ biomarkers in Alzheimer's disease.
目前缺乏用于阿尔茨海默病血浆淀粉样β蛋白（Aβ）定量分析的高性能、资源高效型方法；现有的基于质谱的检测方法资源消耗大且耗时。我们开发了一种简化的质谱方法，该方法只需一步免疫沉淀步骤、优化的缓冲液系统，且抗体需求量减少了75%以上。将该方法的分析性能和临床性能与一种内部重现的著名两步法检测进行了比较。简化后的检测方法显示出高稀释线性（r>0.99）和精密度（变异系数<10%）、低定量限（Aβ1-40：12.5 pg/ml；Aβ1-42：3.125 pg/ml），并且与两步免疫沉淀检测具有高信号相关性（r~0.7）。这种新型单步检测方法通过更少的免疫沉淀步骤显示出更高效的Aβ肽回收率，即使在血浆样本体积低至50 pl时，信噪比也显著更高。在区分脑Aβ-PET水平未升高与升高的个体方面，两种检测方法具有同等性能。这种新方法能够对阿尔茨海默病血浆Aβ生物标志物进行简化而可靠的评估。
