Diagnostic of Novel Plasma Biomarkers in Controls, SCD and MCI Subjects

Abstract

AbstractBackgroundAlzheimer’s disease (AD) is the most common cause of dementia, and a challenging disease for the development of plasma biomarkers. Blood samples are the most easily collectable samples for medical diagnosis. This study evaluates the potential of plasma biomarkers in identifying early stages of AD.Method189 participants were recruited at the NYU Alzheimer Disease Research Center. This cohort includes n = 75 with normal cognition (NL), n = 77 with subjective cognitive decline (SCD), n = 37 with mild cognitive impairment (MCI). Comprehensive neuropsychological and magnetic resonance imaging evaluations were conducted for all patients. Plasma biomarkers assays (total tau [t‐tau], neurofilament light [NfL], glial fibrillary acid protein [GFAP], ubiquitin carboxyl‐terminal hydrolase L1 [UCH‐L1], Aβ1‐42, Aβ1‐40 and pTau181) were measured using the SIMOA SR‐X, a novel technology that employs highly sensitive immunoassays with a limit of detection (LOD) under 100 fg/ml.ResultThe levels of NfL, t‐Tau, GFAP and UCH‐L1 were measured using the Neurology 4‐plex A. NfL levels showed a significant difference between NL and SCD (one tailed t‐ test p = 0.0459). GFAP showed statistically significant differences between NL and MCI, (one tailed t‐test p = 0.0369). Aβ1‐42 showed a significant difference between SCD and MCI (one tailed t‐test p = 0.0493). pTau181 levels showed a significant difference between NL, SCD and NL, MCI (p = 0.0447 and p = 0.0439, respectively). The ratio of pTau181/Aβ1‐42 shows a significant difference between NL and MCI (one tailed t‐test p = 0.0187). Correlation of these biomarkers with brain imaging and cognitive measures is underway.ConclusionBiomarker levels of NfL, GFAP, Aβ1‐42, pTau181 and Ratio pTau181/Aβ1‐42 in plasma samples showed several significant differences between the three groups of subjects. Plasma biomarkers can be useful for the diagnosis of AD related pathology at early stages.