Tau protein pathology

The biology and pathophysiology of tau is complex, requiring different types of tau biomarkers.⁵ Tau biomarkers include tau-PET and CSF concentrations of p-tau.⁵ Evidence of p-tau at specific sites had led to the idea that specific tau phosphorylation signatures are associated with specific disease stages.⁵ CSF concentrations of Aß/p-Tau , and PET measures of insoluble Aß and tau NFTs represent different aspects of AD pathology.⁵ CSF biomarkers indicate the concentration of abnormal proteins that have leaked from brain tissue into the CSF.⁵ In contrast, PET biomarkers bind with high sensitivity and selectivity to insoluble forms of AD pathophysiology such as Aß plaques or tau NFTs.⁵ CSF biomarkers are therefore considered as measures of a pathophysiological process associated with specific neuropathological abnormalities within the brain, while PET biomarkers are thought to show the accumulation of pathology over time.⁵

References:
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5.Therriault J, Zimmer ER, Benedet AL, et al. Staging of Alzheimer’s disease: past, present, and future perspectives. Trends Mol Med 2022; 28 (9): 726–741.