Plasma amyloid‐β profiles and the correlation with neuropsychological performance in patients with cognitive decline

Abstract

AbstractBackgroundThis study aimed to investigate the relationship between the level of plasma amyloid‐β (Aβ) and neuropsychological performance in patients with cognitive decline, classified according to amyloid PET positivity using a highly sensitive nano‐biosensing platform.MethodA total of 44 patients with cognitive decline who underwent plasma Aβ analysis, amyloid PET scanning, and detailed neuropsychological tests were recruited in this study. The participants comprised 20 patients with subjective cognitive decline, 7 with amnestic mild cognitive impairment, and 17 with probable AD dementia. 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 Aβ (Aβ40, Aβ42, and Aβ42/40) levels were associated with neuropsychological test results.ResultThe plasma levels of Aβ42/40 were significantly different between the NC and AD groups and were the best predictor of amyloid positivity by receiver operating characteristic curve analysis. 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. However, in multivariate regression analysis, upon inclusion of age, education, vascular risk factors, and apolipoprotein E ε4 status, higher levels of plasma Aβ42/40 showed significant negative correlations with verbal and visual memory performance, including immediate recall, delayed recall, and recognition tests.ConclusionWe suggest that our study might have clinical significance because plasma Aβ analysis using a highly sensitive nano‐biosensing platform could not only be a useful non‐invasive method for diagnosing AD, but also showed a significant association with memory performance in patients with cognitive decline. Further investigations with a larger sample size are necessary to clarify the possible relevance of plasma Aβ as a blood‐based biomarker for precise AD diagnosis.