Normalization of CSF pTau measurement by A?40 improves its performance as a biomarker of Alzheimer's disease.

ABSTRACT: BACKGROUND:Alzheimer's disease (AD)-related tauopathy can be measured with CSF phosphorylated tau (pTau) and tau PET. We aim to investigate the associations between these measurements and their relative ability to predict subsequent disease progression. METHODS:In 219 cognitively unimpaired and 122 impaired Alzheimer's Disease Neuroimaging Initiative participants with concurrent amyloid-? (A?) PET (18F-florbetapir or 18F-florbetaben), 18F-flortaucipir (FTP) PET, CSF measurements, structural MRI, and cognition, we examined inter-relationships between these biomarkers and their predictions of subsequent FTP and cognition changes. RESULTS:The use of a CSF pTau/A?40 ratio eliminated positive associations we observed between CSF pTau alone and CSF A?42 in the normal A? range likely reflecting individual differences in CSF production rather than pathology. Use of the CSF pTau/A?40 ratio also increased expected associations with A? PET, FTP PET, hippocampal volume, and cognitive decline compared to pTau alone. In A?+ individuals, abnormal CSF pTau/A?40 only individuals (26.7%) were 4 times more prevalent (p?

SUBMITTER: Guo T 

PROVIDER: S-EPMC7429887 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature