New Publication!
Congratulations to Drs. Steven DeKosky, Nikolaus McFarland, and Melissa Armstrong on the publication of “Factors associated with discordant visual and quantitative amyloid PET results,” which appears in the January issue of Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring.
Abstract
INTRODUCTION
Factors underlying discordant visual and quantitative amyloid beta–positron emission tomography (Aβ‐PET) results and their clinical implications are not well understood.
METHODS
Participants from the 1Florida Alzheimer’s Disease Research Center (1FLADRC) underwent Aβ‐PET, blood draw, brain magnetic resonance imaging (MRI), and neuropsychological testing. We evaluated differences in demographics, apolipoprotein E (APOE) status, biomarkers, and cognition among older adults with concordant and discordant visual‐quantitative Aβ‐PET. Discordance was defined as positive visual read (V) of Aβ‐PET with below‐threshold Centiloid quantification (Q; CL <25; V+/Q–) or negative visual read with CL ≥25 (V–/Q+).
RESULTS
We studied 386 participants (mean age ± SD: 70.7 ± 7.8, 55.2% female, 44.6% Hispanic White). Compared to V+/Q–, V–/Q+ had a higher frequency of APOE ε4 carriers (40%). Black/African American participants were overrepresented in V–/Q+ (40.9%). Both discordant groups had higher plasma phosphorylated tau 217 (p‐tau217) and glial fibrillary acidic protein (GFAP) than V–/Q– but lower than V+/Q+. Discordant groups had greater gray matter volume and better cognitive performance than V+/Q+.
DISCUSSION
Discordant Aβ‐PET findings likely hold clinical significance and may reflect early stages of neuropathological progression.