Title | PET Tau and Amyloid-β Burden in Mild Alzheimer's Disease: Divergent Relationship with Age, Cognition, and Cerebrospinal Fluid Biomarkers. |
Publication Type | Journal Article |
Year of Publication | 2017 |
Authors | Koychev, I, Gunn, RN, Firouzian, A, Lawson, J, Zamboni, G, Ridha, B, Sahakian, BJ, Rowe, JB, Thomas, A, Rochester, L, Ffytche, D, Howard, R, Zetterberg, H, MacKay, C, Lovestone, S |
Corporate Authors | Deep and Frequent Phenotyping study team ( |
Journal | J Alzheimers Dis |
Volume | 60 |
Issue | 1 |
Pagination | 283-293 |
Date Published | 2017 |
ISSN | 1875-8908 |
Abstract | BACKGROUND: Combining PET amyloid-β (Aβ) and tau imaging may be critical for tracking disease progression in Alzheimer's disease (AD). OBJECTIVE: We sought to characterize the relationship between Aβ and tau ligands as well as with other measures of pathology. METHODS: We conducted a multi-center observational study in early AD (MMSE >20) participants aged 50 to 85 y. The schedule included cognitive assessments (ADAS-Cog) and CSF measurement of Aβ and tau at baseline and 6 months; PET-CT imaging with Aβ ([18F]AV45) and tau ([18F]AV1451) ligands at baseline. RESULTS: 22 participants took part in the study with 20 completing its 6-month duration and 12 having both tau and amyloid PET. The PET biomarker analysis revealed a strong negative correlation between age and tau in multiple regions. Entorhinal cortex tau and age interacted significantly in terms of cognitive change over 6 months which may have been to older participants deteriorating faster despite lower levels of cortical tau. Cortical Aβ associated with entorhinal cortex tau while CSF tau/Aβ ratio correlated strongly with cortical tau but not Aβ. CONCLUSION: The negative relationship between age and cortical tau whereby younger patients with mild AD had relatively greater tau burden is potentially important. It suggests that younger-age onset AD may be primarily driven by tau pathology while AD developing later may depend on a multitude of pathological mechanisms. These data also suggest that PET-tau performs better than PET-amyloid in predicting the best validated AD diagnostic marker- the CSF total tau/Aβ ratio. |
DOI | 10.3233/JAD-170129 |
Alternate Journal | J. Alzheimers Dis. |
PubMed ID | 28800330 |
PubMed Central ID | PMC5612013 |