Associations between plasma biomarkers and cognition in patients with alzheimer’s disease and amnestic mild cognitive impairment: A cross- sectional and longitudinal study

Abstract

Brain degeneration in patients with Alzheimer’s disease (AD) results from the accumulation of pathological amyloid-β (Aβ) plaques and tau protein tangles, leading to altered plasma levels of biomarkers. However, few studies have investigated the association between plasma biomarkers and cognitive impairment in patients with AD. In this cross-sectional study, we investigated correlations between mini-mental state examination (MMSE) scores and levels of plasma biomarkers in patients with amnestic mild cognitive impairment (aMCI) and AD. Thirteen individuals with normal cognition, 40 patients with aMCI, and 37 patients with AD were enrolled. Immunomagnetic reduction was used to assess the levels of plasma biomarkers, including amyloid Aβ1-40, Aβ1-42, total tau protein (t-Tau), and phosphorylated tau protein (threonine 181, p-Tau181). Our analysis revealed a significant negative correlation between MMSE and both measures of tau, and a trend toward negative correlation between MMSE and Aβ1-42. In a longitudinal study involving three patients with aMCI and two patients with AD, we observed strong negative correlations (r