Plasma Aβ42 and Total Tau Predict Cognitive Decline in Amnestic Mild Cognitive Impairment

Area of Science:

• Neurology
• Biochemistry
• Gerontology

Background:

• Alzheimer disease (AD) is linked to brain amyloid-beta (Aβ) and tau peptide levels.
• Mild cognitive impairment (MCI) is a prodromal stage of AD, characterized by cognitive decline.
• Identifying reliable biomarkers for MCI progression is crucial for early intervention.

Purpose of the Study:

• To investigate the predictive ability of plasma Aβ42 and total-tau (t-tau) for cognitive decline in amnestic MCI.
• To evaluate the diagnostic performance of these plasma biomarkers individually and in combination.

Main Methods:

• Quantification of plasma Aβ42 and t-tau using immunomagnetic reduction (IMR) assay in 22 amnestic MCI participants.
• Neuropsychological testing at baseline and annual follow-up (average 1.5 years) to assess cognitive performance.
• Statistical analysis to determine the predictive value of plasma biomarkers for cognitive status changes.

Main Results:

• Elevated plasma Aβ42 and t-tau levels correlated with poorer episodic verbal memory at baseline.
• Higher plasma Aβ42 and t-tau were associated with cognitive decline during the follow-up period.
• The combined product of plasma Aβ42 and t-tau demonstrated superior discriminatory value for predicting cognitive decline compared to individual markers.

Conclusions:

• Plasma Aβ42 and t-tau show potential as predictive biomarkers for cognitive decline in amnestic MCI.
• The combination of plasma Aβ42 and t-tau may enhance the identification of individuals at risk for future cognitive deterioration.
• Further large-scale, long-term studies are necessary to validate these preliminary findings and establish their clinical utility.