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.
Keywords: Alzheimer’s disease (AD); amnestic mild cognitive impairment (aMCI); blood-based biomarkers; fully-automated assays; plasma biomarkers.