Neocortical β-amyloid area is associated with dementia and APOE in the oldest-old
Objective: Apolipoprotein E (APOE) ε2 carriers may be protected from dementia because of reduced levels of cortical β-amyloid. In the oldest-old, however, APOE ε2 carriers have high β-amyloid plaque scores and preserved cognition. We compared different measures of β-amyloid pathology across APOE genotypes in the oldest-old, and their relationship with dementia. Methods: The study included 96 participants from The 90+ Study. Using all information, dementia diagnoses were made. Neuropathological examination included staging for amyloid plaques and β-amyloid cortical percent area stained by NAB228 antibody. Results: Both APOE ε2 and APOE ε4 carriers had high Consortium to Establish a Registry for Alzheimer's Disease plaque scores. However, APOE ε2 carriers had low cortical β-amyloid percent areas. β-amyloid percent area was associated with dementia across APOE genotypes. Conclusions: Lower levels of percent area in APOE ε2 carriers may reflect lower total β-amyloid and may contribute to APOE ε2 carriers' decreased risk of dementia, despite high β-amyloid plaque scores. The relationship between β-amyloid plaques and dementia in the oldest-old may vary by APOE genotype. © 2013 The Alzheimer's Association. All rights reserved.
Berlau, Daniel J.; Corrada, María M.; Robinson, John L.; Geser, Felix; Arnold, Steven E.; Lee, Virginia M.Y.; Kawas, Claudia H.; and Trojanowski, John Q., "Neocortical β-amyloid area is associated with dementia and APOE in the oldest-old" (2013). Regis University Faculty Publications. 605.