[18F]-AV-1451 binding profile in chronic traumatic encephalopathy: a postmortem case series

Autor: Keith A. Johnson, Nil Sáez-Calveras, Ann C. McKee, Sally Ji Who Kim, Marta Marquié, Michael Siao Tick Chong, Ana C. Amaral, Teresa Gomez-Isla, Eline E. Verwer, Prianca Ramanan, Alberto Villarejo-Galende, Cinthya Aguero, Victor E. Alvarez, Maeva Dhaynaut, Matthew P. Frosch, Rachel E. Bennett
Přispěvatelé: Massachusetts General Hospital [Boston], Centro de Investigacion Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III [Madrid] (ISC), Service de médecine nucléaire [CHU Pitié-Salpétrière], CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Laboratoire d'Imagerie Biomédicale (LIB), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Boston University School of Medicine (BUSM), Boston University [Boston] (BU), VA Boston Healthcare System, Center for Alzheimer Research and Treatment [Boston], Harvard Medical School [Boston] (HMS)
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Acta Neuropathologica Communications
Acta Neuropathologica Communications, BioMed Central part of Springer Science, 2019, 7, pp.164. ⟨10.1186/s40478-019-0808-1⟩
Acta Neuropathologica Communications, Vol 7, Iss 1, Pp 1-12 (2019)
ISSN: 2051-5960
DOI: 10.1186/s40478-019-0808-1⟩
Popis: Introduction Chronic traumatic encephalopathy (CTE) is a tauopathy associated to repetitive head trauma. There are no validated in vivo biomarkers of CTE and a definite diagnosis can only be made at autopsy. Recent studies have shown that positron emission tomography (PET) tracer AV-1451 (Flortaucipir) exhibits high binding affinity for paired helical filament (PHF)-tau aggregates in Alzheimer (AD) brains but relatively low affinity for tau lesions in other tauopathies like temporal lobal degeneration (FTLD)-tau, progressive supranuclear palsy (PSP) or corticobasal degeneration (CBD). Little is known, however, about the binding profile of this ligand to the tau-containing lesions of CTE. Objective To study the binding properties of [18F]-AV-1451 on pathologically confirmed CTE postmortem brain tissue samples. Methods We performed [18F]-AV-1451 phosphor screen and high resolution autoradiography, quantitative tau measurements by immunohistochemistry and Western blot and tau seeding activity assays in brain blocks containing hippocampus, superior temporal cortex, superior frontal cortex, inferior parietal cortex and occipital cortex from 5 cases of CTE, across the stages of disease: stage II-III (n = 1), stage III (n = 3), and stage IV (n = 1). Importantly, low or no concomitant classic AD pathology was present in these brains. Results Despite the presence of abundant tau aggregates in multiple regions in all CTE brains, only faint or no [18F]-AV-1451 binding signal could be detected by autoradiography. The only exception was the presence of a strong signal confined to the region of the choroid plexus and the meninges in two of the five cases. Tau immunostaining and Thioflavin-S staining ruled out the presence of tau aggregates in those regions. High resolution nuclear emulsion autoradiography revealed the presence of leptomeningeal melanocytes as the histologic source of this off-target binding. Levels of abnormally hyperphosphorylated tau species, as detected by Western Blotting, and tau seeding activity were both found to be lower in extracts from cases CTE when compared to AD. Conclusion AV-1451 may have limited utility for in vivo selective and reliable detection of tau aggregates in CTE. The existence of disease-specific tau conformations may likely explain the differential binding affinity of this tracer for tau lesions in different tauopathies.
Databáze: OpenAIRE
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