Performance of Fully-Automated High-Throughput Plasma Biomarker Assays for Alzheimer’s Disease in Amnestic Mild Cognitive Impairment Subjects

Introduction: Novel plasma biomarkers are promising for identifying Alzheimer’s disease (AD) pathological processes in vivo, but most currently employed assays have limitations precluding widespread use. Methods: CSF and plasma samples were collected from seventy amnestic mild cognitive impairment (aMCI) subjects, stratified as A+ and A−. CSF Aβ40, Aβ42, p-tau181 and t-tau and plasma Aβ40, Aβ42 and p-tau181 quantification were conducted using the Lumipulse G assays (Fujirebio), to evaluate the diagnostic performance of plasma biomarkers and assess their associations with CSF biomarkers. Results: All plasma biomarkers except Aβ40 showed a very good accuracy in distinguishing A+ aMCI from A− aMCI, Aβ42/p-tau181 ratio being the most accurate (AUC 0.895, sensitivity 95.1%, specificity 82.8%). Plasma biomarkers levels were significantly associated with CSF biomarkers concentration. Discussion: High-throughput and fully-automated plasma assays could be helpful in discriminating with high accuracy between aMCI in the AD continuum and aMCI unlikely due to AD in clinical settings.