Association Between Plasma Amyloid-β and Neuropsychological Performance in Patients With Cognitive Decline

Objective: To investigate the association between plasma amyloid-beta (A beta) levels and neuropsychological performance in patients with cognitive decline using a highly sensitive nano-biosensing platform. Methods: We prospectively recruited 44 patients with cognitive decline who underwent plasma A beta analysis, amyloid positron emission tomography (PET) scanning, and detailed neuropsychological tests. Patients were classified into a normal control (NC, n = 25) or Alzheimer's disease (AD, n = 19) group based on amyloid PET positivity. Multiple linear regression was performed to determine whether plasma A beta (A beta(40), A beta(42), and A beta(42/40)) levels were associated with neuropsychological test results. Results: The plasma levels of A beta(42/40) were significantly different between the NC and AD groups and were the best predictor of amyloid PET positivity by receiver operating characteristic curve analysis [area under the curve of 0.952 (95% confidence interval, 0.892-1.000)]. Although there were significant differences in the neuropsychological performance of cognitive domains (language, visuospatial, verbal/visual memory, and frontal/executive functions) between the NC and AD groups, higher levels of plasma A beta(42/40) were negatively correlated only with verbal and visual memory performance. Conclusion: Our results demonstrated that plasma A beta analysis using a nano-biosensing platform could be a useful tool for diagnosing AD and assessing memory performance in patients with cognitive decline.

Automated summary

The study found significant differences in plasma A beta (42/40) levels between the normal control group and Alzheimer's disease group, which best predicted the amyloid PET positivity. Higher levels of plasma A beta (42/40) were negatively correlated with verbal and visual memory performance.