Association of plasma biomarkers of amyloid and neurodegeneration with cerebrovascular disease and Alzheimer's disease

The objective of this study was to determine the differential mapping of plasma biomarkers to post-mortem neuropathology measures. We identified 64 participants in a population-based study with anteplasma markers (amyloid-beta [A,beta] x-42, A beta x-40, neurofilament light [NfL], and total tau [T-tau]) who also had neuropathologic assessments of Alzheimer's and cerebrovascular pathology. We conducted weighted linear-regression models to evaluate relationships between plasma measures and neuropathology. Higher plasma NfL and A beta 42/40 ratio were associated with cerebrovascular neuropathologic scales ( p < 0.05) but not with Braak stage, neuritic plaque score, or Thal phase. Plasma A beta 42/40 and NfL explained up to 18% of the variability in cerebrovascular neuropathologic scales. In participants predominantly with modest levels of Alzheimer's pathologic change, biomarkers of amyloid and neurodegeneration were associated with cerebrovascular neuropathology. NfL is a non-specific marker of brain injury, therefore its association with cerebrovascular neuropathology was expected. The association between elevated A beta 42/40 and cerebrovascular disease pathology needs further investigation but could be due to the use of less specific amyloid-beta assays (x-40, x-42).(c) 2022 Elsevier Inc. All rights reserved.