In:
Alzheimer's & Dementia, Wiley, Vol. 16, No. S4 ( 2020-12)
Abstract:
Tau aggregates are one of key pathological features of Alzheimer's disease (AD) and other neurodegenerative diseases. Recently, PET probes for tau have been developed for in vivo detection of tau accumulation, but have limitations such as off‐target binding and lower ability to detect tau in non‐AD tauopathies. Preclinically, a tau tracer, 18 F‐PI‐2620, has a high binding‐affinity and specificity for aggregated tau, and was indicated to have desirable properties for visualization of tau accumulation in both AD and non‐AD tauopathies (Kroth H. et al, Eur J Nucl Med Mol Imaging, 2019). The aim of present study is to assess the ability of 18 F‐PI‐2620 to detect regional tau burden in AD and non‐AD tauopathies. Method We recruited healthy volunteers (N=4, 64‐79 years old), patients with AD (N=4, 65‐80 years old), and with non‐AD tauopathies (three PSP cases and two CBS cases) (N=5, 65‐78 years old). One clinically diagnosed PSP case was pathologically confirmed as CBD after the autopsy. PET imaging with 18 F‐PI‐2620 was performed, and its accumulation in the cortical and subcortical region were assessed by calculating standardized uptake value ratios (SUVR), along with amyloid PET using 18 F‐flobetaben. Furthermore, a postmortem analysis for radio‐pathological correlation was performed in one CBD patient. Result In AD, focal retention of 18 F‐PI‐2620 was apparent in the temporal, parietal, and cingulate cortex. SUVR analysis revealed that more prominent uptake in the globus pallidus (GP) and midbrain was observed in PSP, CBS, and CBD cases in comparison to AD cases, whereas such discrepancies were not apparent in other regions with expected four repeat (4R) tau accumulation. In a CBD case, radio‐pathological analysis failed to show a strong correlation between region‐matched 18 F‐PI‐2620 retention in vivo and postmortem burden of tau (AT8 immunohistochemistry). Conclusion Although 18 F‐PI‐2620 may be a promising tracer for tau in AD cases, in vivo retention of this tracer doesn't correlate with expected 4R tau burden in non‐AD tauopathies. 18 F‐PI‐2620 may have limited utility for reliable detection of 4R tau pathology.
Type of Medium:
Online Resource
ISSN:
1552-5260
,
1552-5279
Language:
English
Publisher:
Wiley
Publication Date:
2020
detail.hit.zdb_id:
2201940-6
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