HAI Book 2025 - Flipbook - Page 699
Phillips, Jeffrey
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PI-2620 uptake in the medial temporal lobes discriminates
Alzheimer9s disease from normal cognition and non-Alzheimer9s dementias
Jeffrey Phillips1, Sevila Temirova1, Dahlia Kamel1, Marianthi Hareras1, Chigozie Ibe1, Quinn
Hlava1, Emily Xie1, Katheryn Cousins1, Leslie Shaw1, Sandhitsu Das1, Jeffrey Maneval1, Sara
Manning1, Christopher Brown1, Katherine Lopez2, Richard Keegan2, Andrew Stephens2, Corey
McMillan1, David Irwin1, Elizabeth Li1, Ilya Nasrallah1, David Wolk1
1
University of Pennsylvania, Philadelphia, PA, US
Life Molecular Imaging, Inc., Boston, MA, US
2
We assessed validity and sensitivity of the PET tracer [F18]-PI-2620 for detecting Alzheimer9s disease (AD)-type
tau across 47 scans from 39 individuals with mixed dementia syndromes (n=27) and normal cognition (n=12) by
testing associations of uptake with grey matter atrophy, plasma biomarkers, and cognition. Clinical syndromes
included amnestic AD (n=7), mild cognitive impairment (n=5), primary progressive aphasia (logopenic PPA, n=3;
non-fluent/agrammatic, n=2; mixed, n=2), posterior cortical atrophy (n=3), dementia with Lewy bodies (n=1),
progressive supranuclear palsy (PSP, n=1), corticobasal syndrome (n=1), and others (n=2). Amyloid-b positivity was
determined from amyloid PET or amyloid-b 42/40 ratio in cerebrospinal fluid. Imaging was performed 45-75
minutes (n=24) or 30-60 minutes (PSP and naPPA) post-injection, and standardized uptake value ratios (SUVRs)
were computed relative to an inferior cerebellar grey matter reference. Average maps in amnestic and nonamnestic AD recapitulated canonical patterns of tau accumulation (Fig. 1). In BA35/ERC, an area of early tau
accumulation in AD, SUVRs were correlated (Fig. 2) with plasma glial fibrillary acidic protein (n=9, p
