Associations Between Plasma Biomarkers and Cognition in Patients with Alzheimer's Disease and Amnestic Mild Cognitive Impairment: A Cross-Sectional and Longitudinal Study
38 Pages Posted: 8 Oct 2019More...
Background: Brain degeneration in patients with Alzheimer's disease (AD) results from the accumulation of pathological amyloid β 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.
Methods: 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 levels of plasma biomarkers, including amyloid β 1-40 (Aβ1-40), Aβ1-42, total Tau protein (t-Tau), and phosphorylated Tau protein (threonine 181, p-Tau181).
Findings: 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 < −0.8) between changes in MMSE scores and plasma levels of t-Tau.
Interpretation: Our results suggest that plasma levels of t-Tau and pTau181 can be used to assess the severity of cognitive impairment in patients with AD. Furthermore, the results of our preliminary longitudinal study suggest that levels of t-Tau can be used to monitor the progression of cognitive decline in patients with aMCI/AD.
Funding Statement: This study was supported in part by grants from the Ministry of Science and Technology of Taiwan (MOST 105-2314-B-016-004-, MOST 106-2314-B-016-007-MY2, MOST 108-2314-B-016-020-, MOST 108-2314-B-016-023-) and TSGH (Grant no TSGH-C101-159, TSGH-C106-068, TSGH-C108-100, TSGH-C108-216).
Declaration of Interests: The authors declare that they have no competing interests.
Ethics Approval Statement: All volunteers or their main caregivers provided written informed consent prior to study enrolment. The study was approved by the institutional review board of the Tri-Service General Hospital (TSGHIRB 1-107-05-111).
Keywords: Alzheimer's disease, amnestic mild cognitive impairment, plasma biomarkers, immunomagnetic reduction
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