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Burnham SC, Iaccarino L, Pontecorvo MJ, Fleisher AS, Lu M, Collins EC, Devous MD. A review of the flortaucipir literature for positron emission tomography imaging of tau neurofibrillary tangles. Brain Commun 2023; 6:fcad305. [PMID: 38187878 PMCID: PMC10768888 DOI: 10.1093/braincomms/fcad305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/13/2023] [Accepted: 11/14/2023] [Indexed: 01/09/2024] Open
Abstract
Alzheimer's disease is defined by the presence of β-amyloid plaques and neurofibrillary tau tangles potentially preceding clinical symptoms by many years. Previously only detectable post-mortem, these pathological hallmarks are now identifiable using biomarkers, permitting an in vivo definitive diagnosis of Alzheimer's disease. 18F-flortaucipir (previously known as 18F-T807; 18F-AV-1451) was the first tau positron emission tomography tracer to be introduced and is the only Food and Drug Administration-approved tau positron emission tomography tracer (Tauvid™). It has been widely adopted and validated in a number of independent research and clinical settings. In this review, we present an overview of the published literature on flortaucipir for positron emission tomography imaging of neurofibrillary tau tangles. We considered all accessible peer-reviewed literature pertaining to flortaucipir through 30 April 2022. We found 474 relevant peer-reviewed publications, which were organized into the following categories based on their primary focus: typical Alzheimer's disease, mild cognitive impairment and pre-symptomatic populations; atypical Alzheimer's disease; non-Alzheimer's disease neurodegenerative conditions; head-to-head comparisons with other Tau positron emission tomography tracers; and technical considerations. The available flortaucipir literature provides substantial evidence for the use of this positron emission tomography tracer in assessing neurofibrillary tau tangles in Alzheimer's disease and limited support for its use in other neurodegenerative disorders. Visual interpretation and quantitation approaches, although heterogeneous, mostly converge and demonstrate the high diagnostic and prognostic value of flortaucipir in Alzheimer's disease.
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Affiliation(s)
| | | | | | | | - Ming Lu
- Avid, Eli Lilly and Company, Philadelphia, PA 19104, USA
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2
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Cools R, Kerkhofs K, Leitao RCF, Bormans G. Preclinical Evaluation of Novel PET Probes for Dementia. Semin Nucl Med 2023; 53:599-629. [PMID: 37149435 DOI: 10.1053/j.semnuclmed.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/24/2023] [Indexed: 05/08/2023]
Abstract
The development of novel PET imaging agents that selectively bind specific dementia-related targets can contribute significantly to accurate, differential and early diagnosis of dementia causing diseases and support the development of therapeutic agents. Consequently, in recent years there has been a growing body of literature describing the development and evaluation of potential new promising PET tracers for dementia. This review article provides a comprehensive overview of novel dementia PET probes under development, classified by their target, and pinpoints their preclinical evaluation pathway, typically involving in silico, in vitro and ex/in vivo evaluation. Specific target-associated challenges and pitfalls, requiring extensive and well-designed preclinical experimental evaluation assays to enable successful clinical translation and avoid shortcomings observed for previously developed 'well-established' dementia PET tracers are highlighted in this review.
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Affiliation(s)
- Romy Cools
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Kobe Kerkhofs
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; NURA, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Renan C F Leitao
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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3
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Matsuda H, Yamao T. Tau positron emission tomography in patients with cognitive impairment and suspected Alzheimer's disease. Fukushima J Med Sci 2023; 69:85-93. [PMID: 37302841 PMCID: PMC10480511 DOI: 10.5387/fms.2023-08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 05/10/2023] [Indexed: 06/13/2023] Open
Abstract
Alzheimer's disease (AD) is diagnosed by the presence of both amyloid β and tau proteins. Recent advances in molecular PET imaging have made it possible to assess the accumulation of these proteins in the living brain. PET ligands have been developed that bind to 3R/4R tau in AD, but not to 3R tau or 4R tau alone. Of the first-generation PET ligands, 18F-flortaucipir has recently been approved by the Food and Drug Administration. Several second-generation PET probes with less off-target binding have been developed and are being applied clinically. Visual interpretation of tau PET should be based on neuropathological neurofibrillary tangle staging instead of a simple positive or negative classification. Four visual read classifications have been proposed: "no uptake," "medial temporal lobe (MTL) only," "MTL AND," and "outside MTL." As an adjunct to visual interpretation, quantitative analysis has been proposed using MRI-based native space FreeSurfer parcellations. The standardized uptake value ratio of the target area is measured using the cerebellar gray matter as a reference region. In the near future, the Centiloid scale of tau PET is expected to be used as a harmonized value for standardizing each analytical method or PET ligand used, similar to amyloid PET.
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Affiliation(s)
- Hiroshi Matsuda
- Department of Biofunctional Imaging, Fukushima Medical University
| | - Tensho Yamao
- Department of Radiological Sciences, School of Health Sciences, Fukushima Medical University
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4
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Varlow C, Vasdev N. Evaluation of Tau Radiotracers in Chronic Traumatic Encephalopathy. J Nucl Med 2023; 64:460-465. [PMID: 36109185 PMCID: PMC10071800 DOI: 10.2967/jnumed.122.264404] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/06/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
Chronic traumatic encephalopathy (CTE) is a neurologic disorder associated with head injuries, diagnosed by the perivascular accumulation of hyperphosphorylated tau protein (phospho-tau) identified at autopsy. Tau PET radiopharmaceuticals developed for imaging Alzheimer disease are under evaluation for brain injuries. The goal of this study was to conduct a head-to-head in vitro evaluation of 5 tau PET radiotracers in subjects pathologically diagnosed with CTE. Methods: Autoradiography was used to assess the specific binding and distribution of 3H-flortaucipir (also known as Tauvid, AV-1451, and T807), 3H-MK-6240 (also known as florquinitau), 3H-PI-2620, 3H-APN-1607 (also known as PM-PBB3 and florzolotau), and 3H-CBD-2115 (also known as 3H-OXD-2115) in fresh-frozen human postmortem CTE brain tissue (stages I-IV). Immunohistochemistry was performed for phospho-tau with AT8, 3R tau with RD3, 4R tau with RD4 and amyloid-β with 6F/3D antibodies. Tau target density (maximum specific binding) was quantified by saturation analysis with 3H-flortaucipir in tissue sections. Results: 3H-flortaucipir demonstrated a positive signal in all CTE cases examined, with varying degrees of specific binding (68.7% ± 10.5%; n = 12) defined by homologous blockade and to a lesser extent by heterologous blockade with MK-6240 (27.3% ± 13.6%; n = 12). The 3H-flortaucipir signal was also displaced by the monoamine oxidase (MAO)-A inhibitor clorgyline (43.9% ± 4.6%; n = 3), indicating off-target binding to MAO-A. 3H-APN-1607 was moderately displaced in homologous blocking studies and was not displaced by 3H-flortaucipir; however, substantial displacement was observed when blocking with the β-amyloid-targeting compound NAV-4694. 3H-MK-6240 and 3H-PI-2620 had negligible binding in all but 2 CTE IV cases, and binding may be attributed to pathology severity or mixed Alzheimer disease/CTE pathology. 3H-CBD-2115 showed moderate binding, displaced under homologous blockade, and aligned with 4R-tau immunostaining. Conclusion: In human CTE tissues, 3H-flortaucipir and 3H-APN-1607 revealed off-target binding to MAO-A and amyloid-β, respectively, and should be considered if these radiotracers are used in PET imaging studies of patients with brain injuries. 3H-MK-6240 and 3H-PI-2620 bind to CTE tau in severe- or mixed-pathology cases, and their respective 18F PET radiotracers warrant further evaluation in patients with severe suspected CTE.
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Affiliation(s)
- Cassis Varlow
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, and Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Neil Vasdev
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, and Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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5
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Mohammadi Z, Alizadeh H, Marton J, Cumming P. The Sensitivity of Tau Tracers for the Discrimination of Alzheimer's Disease Patients and Healthy Controls by PET. Biomolecules 2023; 13:290. [PMID: 36830659 PMCID: PMC9953528 DOI: 10.3390/biom13020290] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/12/2023] [Accepted: 01/25/2023] [Indexed: 02/09/2023] Open
Abstract
Hyperphosphorylated tau aggregates, also known as neurofibrillary tangles, are a hallmark neuropathological feature of Alzheimer's disease (AD). Molecular imaging of tau by positron emission tomography (PET) began with the development of [18F]FDDNP, an amyloid β tracer with off-target binding to tau, which obtained regional specificity through the differing distributions of amyloid β and tau in AD brains. A concerted search for more selective and affine tau PET tracers yielded compounds belonging to at least eight structural categories; 18F-flortaucipir, known variously as [18F]-T807, AV-1451, and Tauvid®, emerged as the first tau tracer approved by the American Food and Drug Administration. The various tau tracers differ concerning their selectivity over amyloid β, off-target binding at sites such as monoamine oxidase and neuromelanin, and degree of uptake in white matter. While there have been many reviews of molecular imaging of tau in AD and other conditions, there has been no systematic comparison of the fitness of the various tracers for discriminating between AD patient and healthy control (HC) groups. In this narrative review, we endeavored to compare the binding properties of the various tau tracers in vitro and the effect size (Cohen's d) for the contrast by PET between AD patients and age-matched HC groups. The available tracers all gave good discrimination, with Cohen's d generally in the range of two-three in culprit brain regions. Overall, Cohen's d was higher for AD patient groups with more severe illness. Second-generation tracers, while superior concerning off-target binding, do not have conspicuously higher sensitivity for the discrimination of AD and HC groups. We suppose that available pharmacophores may have converged on a maximal affinity for tau fibrils, which may limit the specific signal imparted in PET studies.
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Affiliation(s)
- Zohreh Mohammadi
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 5166/15731, Iran
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz 5166/15731, Iran
| | - Hadi Alizadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 5166/15731, Iran
| | - János Marton
- ABX Advanced Biochemical Compounds Biomedizinische Forschungsreagenzien GmbH, Heinrich-Glaeser-Straße 10-14, D-01454 Radeberg, Germany
| | - Paul Cumming
- Department of Nuclear Medicine, Bern University Hospital, Freiburgstraße 18, CH-3010 Bern, Switzerland
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD 4059, Australia
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Josephs KA, Tosakulwong N, Gatto RG, Weigand SD, Ali F, Botha H, Graff‐Radford J, Machulda MM, Savica R, Schwarz CG, Senjem ML, Boeve BF, Kantarci K, Jones DT, Ramanan VK, Fields JA, Reichard RR, Dickson DW, Petersen RC, Jack CR, Lowe VJ, Whitwell JL. Optimum Differentiation of Frontotemporal Lobar Degeneration from Alzheimer Disease Achieved with Cross-Sectional Tau Positron Emission Tomography. Ann Neurol 2022; 92:1016-1029. [PMID: 36054427 PMCID: PMC9804568 DOI: 10.1002/ana.26479] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 01/25/2023]
Abstract
OBJECTIVE This study was undertaken to assess cross-sectional and longitudinal [18 F]-flortaucipir positron emission tomography (PET) uptake in pathologically confirmed frontotemporal lobar degeneration (FTLD) and to compare FTLD to cases with high and low levels of Alzheimer disease (AD) neuropathologic changes (ADNC). METHODS One hundred forty-three participants who had completed at least one flortaucipir PET and had autopsy-confirmed FTLD (n = 52) or high (n = 58) or low ADNC (n = 33) based on Braak neurofibrillary tangle stages 0-IV versus V-VI were included. Flortaucipir standard uptake value ratios (SUVRs) were calculated for 9 regions of interest (ROIs): an FTLD meta-ROI, midbrain, globus pallidum, an AD meta-ROI, entorhinal, inferior temporal, orbitofrontal, precentral, and medial parietal. Linear mixed effects models were used to compare mean baseline SUVRs and annual rate of change in SUVR by group. Sensitivity and specificity to distinguish FTLD from high and low ADNC were calculated. RESULTS Baseline uptake in the FTLD meta-ROI, midbrain, and globus pallidus was greater in FTLD than high and low ADNC. No region showed a greater rate of flortaucipir accumulation in FTLD. Baseline uptake in the AD-related regions and orbitofrontal and precentral cortices was greater in high ADNC, and all showed greater rates of accumulation compared to FTLD. Baseline differences were superior to longitudinal rates in differentiating FTLD from high and low ADNC. A simple baseline metric of midbrain/inferior temporal ratio of flortaucipir uptake provided good to excellent differentiation between FTLD and high and low ADNC (sensitivities/specificities = 94%/95% and 71%/70%). INTERPRETATION There are cross-sectional and longitudinal differences in flortaucipir uptake between FTLD and high and low ADNC. However, optimum differentiation between FTLD and ADNC was achieved with baseline uptake rather than longitudinal rates. ANN NEUROL 2022;92:1016-1029.
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Affiliation(s)
| | | | | | | | - Farwa Ali
- Department of NeurologyMayo ClinicRochesterMNUSA
| | - Hugo Botha
- Department of NeurologyMayo ClinicRochesterMNUSA
| | | | - Mary M. Machulda
- Department of Psychiatry and PsychologyMayo ClinicRochesterMNUSA
| | | | | | - Matthew L. Senjem
- Department of RadiologyMayo ClinicRochesterMNUSA
- Department of Information TechnologyMayo ClinicRochesterMNUSA
| | | | | | | | | | - Julie A. Fields
- Department of Psychiatry and PsychologyMayo ClinicRochesterMNUSA
| | - Ross R. Reichard
- Department of Laboratory Medicine and PathologyMayo ClinicRochesterMNUSA
| | - Dennis W. Dickson
- Department of Neuroscience (Neurogenetics)Mayo ClinicJacksonvilleFLUSA
| | | | | | - Val J. Lowe
- Department of RadiologyMayo ClinicRochesterMNUSA
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7
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Wright JP, Goodman JR, Lin YG, Lieberman BP, Clemens J, Gomez LF, Liang Q, Hoye AT, Pontecorvo MJ, Conway KA. Monoamine oxidase binding not expected to significantly affect [ 18F]flortaucipir PET interpretation. Eur J Nucl Med Mol Imaging 2022; 49:3797-3808. [PMID: 35596745 PMCID: PMC9399028 DOI: 10.1007/s00259-022-05822-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 04/25/2022] [Indexed: 11/28/2022]
Abstract
Purpose [18F]-labeled positron emission tomography (PET) radioligands permit in vivo assessment of Alzheimer’s disease biomarkers, including aggregated neurofibrillary tau (NFT) with [18F]flortaucipir. Due to structural similarities of flortaucipir with some monoamine oxidase A (MAO-A) inhibitors, this study aimed to evaluate flortaucipir binding to MAO-A and MAO-B and any potential impact on PET interpretation. Methods [18F]Flortaucipir autoradiography was performed on frozen human brain tissue slices, and PET imaging was conducted in rats. Dissociation constants were determined by saturation binding, association and dissociation rates were measured by kinetic binding experiments, and IC50 values were determined by competition binding. Results Under stringent wash conditions, specific [18F]flortaucipir binding was observed on tau NFT-rich Alzheimer’s disease tissue and not control tissue. In vivo PET experiments in rats revealed no evidence of [18F]flortaucipir binding to MAO-A; pre-treatment with MAO inhibitor pargyline did not impact uptake or wash-out of [18F]flortaucipir. [18F]Flortaucipir bound with low nanomolar affinity to human MAO-A in a microsomal preparation in vitro but with a fast dissociation rate relative to MAO-A ligand fluoroethyl-harmol, consistent with no observed in vivo binding in rats of [18F]flortaucipir to MAO-A. Direct binding of flortaucipir to human MAO-B was not detected in a microsomal preparation. A high concentration of flortaucipir (IC50 of 1.3 μM) was found to block binding of the MAO-B ligand safinamide to MAO-B on microsomes suggesting that, at micromolar concentrations, flortaucipir weakly binds to MAO-B in vitro. Conclusion These data suggest neither MAO-A nor MAO-B binding will contribute significantly to the PET signal in cortical target areas relevant to the interpretation of [18F]flortaucipir. Supplementary Information The online version contains supplementary material available at 10.1007/s00259-022-05822-9.
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Affiliation(s)
- Justin P Wright
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Jason R Goodman
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Yin-Guo Lin
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Brian P Lieberman
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Jennifer Clemens
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Luis F Gomez
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Qianwa Liang
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | - Adam T Hoye
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA
| | | | - Kelly A Conway
- Avid Radiopharmaceuticals, Eli Lilly & Company, Philadelphia, PA, USA.
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8
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Kim MH, Jung WJ, Jeong HJ, Lee K, Kil HS, Chung WS, Nam KR, Lee YJ, Lee KC, Lim SM, Chi DY. Off‐target screening of amyloid‐beta plaque targeting [
18
F
]florapronol ([
18
F
]
FC119S
) in postmortem Alzheimer's disease tissues. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Min Hwan Kim
- Research Institute of Radiopharmaceuticals FutureChem Co., Ltd. Seongdong‐gu, Seoul Republic of Korea
| | - Woon Jung Jung
- Research Institute of Radiopharmaceuticals FutureChem Co., Ltd. Seongdong‐gu, Seoul Republic of Korea
| | - Hyeon Jin Jeong
- Research Institute of Radiopharmaceuticals FutureChem Co., Ltd. Seongdong‐gu, Seoul Republic of Korea
| | - Kyongkyu Lee
- Research Institute of Radiopharmaceuticals FutureChem Co., Ltd. Seongdong‐gu, Seoul Republic of Korea
| | - Hee Seup Kil
- Research Institute of Radiopharmaceuticals FutureChem Co., Ltd. Seongdong‐gu, Seoul Republic of Korea
| | - Wee Sup Chung
- Division of Applied RI Korea Institute of Radiological & Medical Sciences Nowon‐gu, Seoul Republic of Korea
| | - Kyung Rok Nam
- Division of Applied RI Korea Institute of Radiological & Medical Sciences Nowon‐gu, Seoul Republic of Korea
| | - Yong Jin Lee
- Division of Applied RI Korea Institute of Radiological & Medical Sciences Nowon‐gu, Seoul Republic of Korea
| | - Kyo Chul Lee
- Division of Applied RI Korea Institute of Radiological & Medical Sciences Nowon‐gu, Seoul Republic of Korea
| | - Sang Moo Lim
- Department of Nuclear Medicine Korea Institute of Radiological & Medical Sciences Nowon‐gu, Seoul Republic of Korea
| | - Dae Yoon Chi
- Research Institute of Radiopharmaceuticals FutureChem Co., Ltd. Seongdong‐gu, Seoul Republic of Korea
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9
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Abstract
Two pathologically distinct neurodegenerative conditions, progressive supranuclear palsy and corticobasal degeneration, share in common deposits of tau proteins that differ both molecularly and ultrastructurally from the common tau deposits diagnostic of Alzheimer disease. The proteinopathy in these disorders is characterized by fibrillary aggregates of 4R tau proteins. The clinical presentations of progressive supranuclear palsy and of corticobasal degeneration are often confused with more common disorders such as Parkinson disease or subtypes of frontotemporal lobar degeneration. Neither of these 4R tau disorders has effective therapy, and while there are emerging molecular imaging approaches to identify patients earlier in the course of disease, there are as yet no reliably sensitive and specific approaches to diagnoses in life. In this review, aspects of the clinical syndromes, neuropathology, and molecular biomarker imaging studies applicable to progressive supranuclear palsy and to corticobasal degeneration will be presented. Future development of more accurate molecular imaging approaches is proposed.
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Affiliation(s)
- Kirk A Frey
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, The University of Michigan Health System, Ann Arbor, MI.
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10
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Hansen AK, Parbo P, Ismail R, Østergaard K, Brooks DJ, Borghammer P. Tau Tangles in Parkinson's Disease: A 2-Year Follow-Up Flortaucipir PET Study. JOURNAL OF PARKINSONS DISEASE 2021; 10:161-171. [PMID: 31815700 DOI: 10.3233/jpd-191774] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Flortaucipir PET, a marker of tau tangles, has shown lower than expected cortical uptake in Parkinson's disease (PD), than would be predicted from neuropathologic estimates of Alzheimer's disease co-pathology. Instead, the most characteristic finding of flortaucipir imaging in PD is decreased uptake in the substantia nigra, reflecting reduction in its "off-target" binding to neuromelanin. We have previously reported these observations in cross-sectional studies. OBJECTIVE Here, we present two-year follow-up data of cortical and nigral flortaucipir uptake in PD patients. METHODS Seventeen PD patients received repeat flortaucipir PET two years after baseline. We interrogated vertex-based group-wise cortical tracer binding (SUVRs) with a cerebellar reference using the general linear model while mean substantia nigra SUVRs were compared with volumes of interest group comparisons and voxel-wise group analyses using ANOVA. Finally, we performed linear regressions of tau load with changes in MoCA and UPDRS motor scores. RESULTS We found no significant changes in substantia nigra or cortex flortaucipir uptake in Parkinson's disease patients over two years and no association with changes in cognitive symptoms. Signal reduction in the medial substantia nigra trended towards an association with worsening of motor symptoms. CONCLUSION No significant increase in tau tangles occurred after a two-year follow-up of Parkinson's disease patients using flortaucipir PET.
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Affiliation(s)
- Allan K Hansen
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Peter Parbo
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Rola Ismail
- PET-Centre, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - David J Brooks
- PET-Centre, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Institute of Neuroscience, Newcastle University, Newcastle, UK.,Division of Brain Sciences, Imperial College London, London, UK
| | - Per Borghammer
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark.,PET-Centre, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
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11
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Pascual B, Funk Q, Zanotti-Fregonara P, Cykowski MD, Veronese M, Rockers E, Bradbury K, Yu M, Nakawah MO, Román GC, Schulz PE, Arumanayagam AS, Beers D, Faridar A, Fujita M, Appel SH, Masdeu JC. Neuroinflammation is highest in areas of disease progression in semantic dementia. Brain 2021; 144:1565-1575. [PMID: 33824991 DOI: 10.1093/brain/awab057] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/25/2020] [Accepted: 12/10/2020] [Indexed: 12/11/2022] Open
Abstract
Despite epidemiological and genetic data linking semantic dementia to inflammation, the topography of neuroinflammation in semantic dementia, also known as the semantic variant of primary progressive aphasia, remains unclear. The pathology starts at the tip of the left temporal lobe where, in addition to cortical atrophy, a strong signal appears with the tau PET tracer 18F-flortaucipir, even though the disease is not typically associated with tau but with TDP-43 protein aggregates. Here, we characterized the topography of inflammation in semantic variant primary progressive aphasia using high-resolution PET and the tracer 11C-PBR28 as a marker of microglial activation. We also tested the hypothesis that inflammation, by providing non-specific binding targets, could explain the 18F-flortaucipir signal in semantic variant primary progressive aphasia. Eight amyloid-PET-negative patients with semantic variant primary progressive aphasia underwent 11C-PBR28 and 18F-flortaucipir PET. Healthy controls underwent 11C-PBR28 PET (n = 12) or 18F-flortaucipir PET (n = 12). Inflammation in PET with 11C-PBR28 was analysed using Logan graphical analysis with a metabolite-corrected arterial input function. 18F-flortaucipir standardized uptake value ratios were calculated using the cerebellum as the reference region. Since monoamine oxidase B receptors are expressed by astrocytes in affected tissue, selegiline was administered to one patient with semantic variant primary progressive aphasia before repeating 18F-flortaucipir scanning to test whether monoamine oxidase B inhibition blocked flortaucipir binding, which it did not. While 11C-PBR28 uptake was mostly cortical, 18F-flortaucipir uptake was greatest in the white matter. The uptake of both tracers was increased in the left temporal lobe and in the right temporal pole, as well as in regions adjoining the left temporal pole such as insula and orbitofrontal cortex. However, peak uptake of 18F-flortaucipir localized to the left temporal pole, the epicentre of pathology, while the peak of inflammation 11C-PBR28 uptake localized to a more posterior, mid-temporal region and left insula and orbitofrontal cortex, in the periphery of the damage core. Neuroinflammation, greatest in the areas of progression of the pathological process in semantic variant primary progressive aphasia, should be further studied as a possible therapeutic target to slow disease progression.
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Affiliation(s)
- Belen Pascual
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Quentin Funk
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Paolo Zanotti-Fregonara
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Matthew D Cykowski
- Department of Pathology and Genomic Medicine, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA.,Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Mattia Veronese
- Centre for Neuroimaging Sciences, King's College London, London, UK
| | - Elijah Rockers
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Kathleen Bradbury
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Meixiang Yu
- Cyclotron and Radiopharmaceutical Core, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Mohammad O Nakawah
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Gustavo C Román
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Paul E Schulz
- Department of Neurology, McGovern Medical School of UT Health, Houston, TX, USA
| | - Anithachristy S Arumanayagam
- Department of Pathology and Genomic Medicine, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - David Beers
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Alireza Faridar
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Masahiro Fujita
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Stanley H Appel
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
| | - Joseph C Masdeu
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, TX, USA
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12
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Leuzy A, Smith R, Ossenkoppele R, Santillo A, Borroni E, Klein G, Ohlsson T, Jögi J, Palmqvist S, Mattsson-Carlgren N, Strandberg O, Stomrud E, Hansson O. Diagnostic Performance of RO948 F 18 Tau Positron Emission Tomography in the Differentiation of Alzheimer Disease From Other Neurodegenerative Disorders. JAMA Neurol 2021; 77:955-965. [PMID: 32391858 PMCID: PMC7215644 DOI: 10.1001/jamaneurol.2020.0989] [Citation(s) in RCA: 118] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Question How does RO948 F 18 positron emission tomographic scanning discriminate between Alzheimer disease and other neurodegenerative disorders in comparison with magnetic resonance imaging and cerebrospinal fluid measures? Findings In this diagnostic study including 613 patients from the Swedish BioFINDER-2 clinical trial, standard uptake value ratios of RO948 F 18 were higher in patients with Alzheimer disease dementia compared with cognitively unimpaired controls and patients with other neurodegenerative disorders; furthermore, RO948 F 18 outperformed magnetic resonance imaging and cerebrospinal fluid measures. Generally, tau positron emission tomographic positivity was confined to amyloid β–positive cases or MAPT R406W mutation carriers in this cohort; in patients with semantic variant primary progressive aphasia, RO948 F 18 retention was lower than that for flortaucipir F 18. Meaning These findings suggest that RO948 F 18 has a high specificity for Alzheimer disease–type tau and highlight its potential as a diagnostic marker in the workup of patients treated in memory clinics. Importance The diagnostic performance of second-generation tau positron emission tomographic (PET) tracers is not yet known. Objective To examine the novel tau PET tracer RO948 F 18 ([18F]RO948) performance in discriminating Alzheimer disease (AD) from non-AD neurodegenerative disorders. Design, Setting, and Participants In this diagnostic study, 613 participants in the Swedish BioFINDER-2 study were consecutively enrolled in a prospective cross-sectional study from September 4, 2017, to August 28, 2019. Participants included 257 cognitively unimpaired controls, 154 patients with mild cognitive impairment, 100 patients with AD dementia, and 102 with non-AD neurodegenerative disorders. Evaluation included a comparison of tau PET tracer [18F]RO948 with magnetic resonance imaging (MRI) and cerebrospinal fluid and a head-to-head comparison between [18F]RO948 and flortaucipir F 18 ([18F]flortaucipir) in patients with semantic variant primary progressive aphasia (svPPA). Exposures [18F]RO948 (all patients) and [18F]flortaucipir (3 patients with svPPA) tau PET; MRI (hippocampal volume, composite temporal lobe cortical thickness, whole-brain cortical thickness) and cerebrospinal fluid measures (p-tau181 and amyloid Aβ42 and Aβ40 ratio[Aβ42/Aβ40], and Aβ42/p-tau181 ratio). Main Outcomes and Measures Standard uptake value ratios (SUVRs) in 4 predefined regions of interest (ROIs) reflecting Braak staging scheme for tau pathology and encompass I-II (entorhinal cortex), III-IV (inferior/middle temporal, fusiform gyrus, parahippocampal cortex, and amygdala), I-IV, and V-VI (widespread neocortical areas), area under the receiver operating characteristic curve (AUC) values, and subtraction images between [18F]RO948 and [18F]flortaucipir. Results Diagnostic groups among the 613 participants included cognitively unimpaired (mean [SD] age, 65.8 [12.1] years; 117 men [46%]), mild cognitive impairment (age, 70.8 [8.3] years; 82 men [53%]), AD dementia (age, 73.5 [6.7] years; 57 men [57%]), and non-AD disorders (age, 70.5 [8.6] years; 41 men [40%]). Retention of [18F]RO948 was higher in AD dementia compared with all other diagnostic groups. [18F]RO948 could distinguish patients with AD dementia from individuals without cognitive impairment and those with non-AD disorders, and the highest AUC was obtained using the I-IV ROI (AUC = 0.98; 95% CI, 0.96-0.99 for AD vs no cognitive impairment and AUC = 0.97; 95% CI, 0.95-0.99 for AD vs non-AD disorders), which outperformed MRI (highest AUC = 0.91 for AD vs no cognitive impairment using whole-brain thickness, and AUC = 0.80 for AD vs non-AD disorders using temporal lobe thickness) and cerebrospinal fluid measures (highest AUC = 0.94 for AD vs no cognitive impairment using Aβ42/p-tau181, and AUC = 0.93 for AD vs non-AD disorders using Aβ42/Aβ40). Generally, tau PET positivity using [18F]RO948 was observed only in Aβ-positive cases or in MAPT R406W mutation carriers. Retention of [18F]RO948 was not pronounced in patients with svPPA, and head-to-head comparison revealed lower temporal lobe uptake than with [18F]flortaucipir. Conclusions and Relevance In this study, elevated [18F]RO948 SUVRs were most often seen among Aβ-positive cases, which suggests that [18F]RO948 has high specificity for AD-type tau and highlights its potential as a diagnostic marker in the differential diagnosis of AD.
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Affiliation(s)
- Antoine Leuzy
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Ruben Smith
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.,Department of Neurology, Skåne University Hospital, Lund, Sweden
| | - Rik Ossenkoppele
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.,Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam, the Netherlands
| | | | | | | | - Tomas Ohlsson
- Department of Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Jonas Jögi
- Skåne University Hospital, Department of Clinical Physiology and Nuclear Medicine, Lund, Sweden
| | - Sebastian Palmqvist
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.,Department of Neurology, Skåne University Hospital, Lund, Sweden
| | - Niklas Mattsson-Carlgren
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.,Department of Neurology, Skåne University Hospital, Lund, Sweden.,Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Olof Strandberg
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Erik Stomrud
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.,Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.,Memory Clinic, Skåne University Hospital, Malmö, Sweden
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13
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Jie CVML, Treyer V, Schibli R, Mu L. Tauvid™: The First FDA-Approved PET Tracer for Imaging Tau Pathology in Alzheimer's Disease. Pharmaceuticals (Basel) 2021; 14:ph14020110. [PMID: 33573211 PMCID: PMC7911942 DOI: 10.3390/ph14020110] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 12/03/2022] Open
Abstract
Tauvid has been approved by the U.S. Food and Drug Administration (FDA) in 2020 for positron emission tomography (PET) imaging of adult patients with cognitive impairments undergoing evaluation for Alzheimer’s disease (AD) based on tau pathology. Abnormal aggregation of tau proteins is one of the main pathologies present in AD and is receiving increasing attention as a diagnostic and therapeutic target. In this review, we summarised the production and quality control of Tauvid, its clinical application, pharmacology and pharmacokinetics, as well as its limitation due to off-target binding. Moreover, a brief overview on the second-generation of Tau PET tracers is provided. The approval of Tauvid marks a step forward in the field of AD research and opens up opportunities for second-generation tau tracers to advance tau PET imaging in the clinic.
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Affiliation(s)
- Caitlin V. M. L. Jie
- Center for Radiopharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zurich, Switzerland; (C.V.M.L.J.); (R.S.)
| | - Valerie Treyer
- Department of Nuclear Medicine, University Hospital Zurich, 8091 Zurich, Switzerland;
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zurich, Switzerland; (C.V.M.L.J.); (R.S.)
| | - Linjing Mu
- Center for Radiopharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zurich, Switzerland; (C.V.M.L.J.); (R.S.)
- Department of Nuclear Medicine, University Hospital Zurich, 8091 Zurich, Switzerland;
- Correspondence:
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14
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Radioactive synthesis of tau PET imaging agent 18F-AV-1451 and its role in monitoring the progression of Alzheimer's disease and supporting differential diagnosis. Ann Nucl Med 2021; 35:139-147. [PMID: 33460010 DOI: 10.1007/s12149-020-01566-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/23/2020] [Indexed: 10/22/2022]
Abstract
Alzheimer's disease (AD) is on the rise all over the world, and brings with it great challenges to medical care and heavy burdens to family and society. Accurate diagnosis and differential diagnosis are of great importance. Tau positron emission tomography (PET) might offer novel insights and be of great assistance in monitoring disease progression and supporting the differential diagnosis. 18F-AV-1451, as the first Tau PET imaging agent approved by the Food and Drug Administration (FDA), has been of great potential in clinical trials. Here, we reviewed the synthesis and characteristics of 18F-AV-1451 and its role in monitoring AD progression and supporting the differential diagnosis.
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15
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Malpetti M, Passamonti L, Rittman T, Jones PS, Rodríguez PV, Bevan-Jones WR, Hong YT, Fryer TD, Aigbirhio FI, O’Brien JT, Rowe JB. Neuroinflammation and Tau Colocalize in vivo in Progressive Supranuclear Palsy. Ann Neurol 2020; 88:1194-1204. [PMID: 32951237 PMCID: PMC7116392 DOI: 10.1002/ana.25911] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVE We examined the relationship between tau pathology and neuroinflammation using [11 C]PK11195 and [18 F]AV-1451 PET in 17 patients with progressive supranuclear palsy (PSP) Richardson's syndrome. We tested the hypothesis that neuroinflammation and tau protein aggregation colocalize macroscopically, and correlate with clinical severity. METHODS Nondisplaceable binding potential (BPND ) for each ligand was quantified in 83 regions of interest (ROIs). The [11 C]PK11195 and [18 F]AV-1451 BPND values were correlated across all regions. The spatial distributions of [11 C]PK11195 and [18 F]AV-1451 binding were determined by principal component analyses (PCAs), and the loading of each spatial component compared against the patients' clinical severity (using the PSP rating scale). RESULTS Regional [11 C]PK11195 and [18 F]AV-1451 binding were positively correlated (R = 0.577, p < 0.0001). The PCA identified 4 components for each ligand, reflecting the relative expression of tau pathology or neuroinflammation in distinct groups of brain regions. Positive associations between [11 C]PK11195 and [18 F]AV-1451 components' loadings were found in both subcortical (R = 0.769, p < 0.0001) and cortical regions (R = 0.836, p < 0.0001). There were positive correlations between clinical severity and both subcortical tau pathology (R = 0.667, p = 0.003) and neuroinflammation (R = 0.788, p < 0.001). INTERPRETATION We show that tau pathology and neuroinflammation colocalize in PSP, and that individual differences in subcortical tau pathology and neuroinflammation are linked to clinical severity. Although longitudinal studies are needed to determine causal associations between these molecular pathologies, we suggest that the combination of tau- and immune-oriented strategies may be useful for effective disease-modifying treatments in PSP. ANN NEUROL 2020;88:1194-1204.
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Affiliation(s)
- Maura Malpetti
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Luca Passamonti
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Institute of Molecular Bioimaging and Physiology, National Research Council, Milano, Italy
| | - Timothy Rittman
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - P. Simon Jones
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | | | | | - Young T. Hong
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | - Tim D. Fryer
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | | | - John T. O’Brien
- Department of Psychiatry, University of Cambridge, Cambridge, UK
- Cambridge University Hospitals NHS Trust, Cambridge, UK
| | - James B. Rowe
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Cambridge University Hospitals NHS Trust, Cambridge, UK
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16
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Kim HR, Lee P, Seo SW, Roh JH, Oh M, Oh JS, Oh SJ, Kim JS, Jeong Y. Comparison of Amyloid β and Tau Spread Models in Alzheimer's Disease. Cereb Cortex 2020; 29:4291-4302. [PMID: 30566579 DOI: 10.1093/cercor/bhy311] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 11/13/2018] [Accepted: 11/16/2018] [Indexed: 11/14/2022] Open
Abstract
Tau and amyloid β (Aβ), 2 key pathogenic proteins in Alzheimer's disease (AD), reportedly spread throughout the brain as the disease progresses. Models of how these pathogenic proteins spread from affected to unaffected areas had been proposed based on the observation that these proteins could transmit to other regions either through neural fibers (transneuronal spread model) or through extracellular space (local spread model). In this study, we modeled the spread of tau and Aβ using a graph theoretical approach based on resting-state functional magnetic resonance imaging. We tested whether these models predict the distribution of tau and Aβ in the brains of AD spectrum patients. To assess the models' performance, we calculated spatial correlation between the model-predicted map and the actual map from tau and amyloid positron emission tomography. The transneuronal spread model predicted the distribution of tau and Aβ deposition with significantly higher accuracy than the local spread model. Compared with tau, the local spread model also predicted a comparable portion of Aβ deposition. These findings provide evidence of transneuronal spread of AD pathogenic proteins in a large-scale brain network and furthermore suggest different contributions of spread models for tau and Aβ in AD.
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Affiliation(s)
- Hang-Rai Kim
- Graduate School of Medical Science & Engineering, KAIST, Daejeon, Republic of Korea.,KAIST Institute for Health Science and Technology, KAIST, Daejeon, Republic of Korea
| | - Peter Lee
- KAIST Institute for Health Science and Technology, KAIST, Daejeon, Republic of Korea.,Department of Bio and Brain Engineering, KAIST, Daejeon, 34141 Republic of Korea
| | - Sang Won Seo
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jee Hoon Roh
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Minyoung Oh
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jungsu S Oh
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Seung Jun Oh
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jae Seung Kim
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yong Jeong
- Graduate School of Medical Science & Engineering, KAIST, Daejeon, Republic of Korea.,KAIST Institute for Health Science and Technology, KAIST, Daejeon, Republic of Korea.,Department of Bio and Brain Engineering, KAIST, Daejeon, 34141 Republic of Korea
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17
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Hammes J, Bischof GN, Bohn KP, Onur Ö, Schneider A, Fliessbach K, Hönig MC, Jessen F, Neumaier B, Drzezga A, van Eimeren T. One-Stop Shop: 18F-Flortaucipir PET Differentiates Amyloid-Positive and -Negative Forms of Neurodegenerative Diseases. J Nucl Med 2020; 62:240-246. [PMID: 32620704 DOI: 10.2967/jnumed.120.244061] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/30/2020] [Indexed: 02/06/2023] Open
Abstract
Tau protein aggregations are a hallmark of amyloid-associated Alzheimer disease and some forms of non-amyloid-associated frontotemporal lobar degeneration. In recent years, several tracers for in vivo tau imaging have been under evaluation. This study investigated the ability of 18F-flortaucipir PET not only to assess tau positivity but also to differentiate between amyloid-positive and -negative forms of neurodegeneration on the basis of different 18F-flortaucipir PET signatures. Methods: The 18F-flortaucipir PET data of 35 patients with amyloid-positive neurodegeneration, 19 patients with amyloid-negative neurodegeneration, and 17 healthy controls were included in a data-driven scaled subprofile model (SSM)/principal-component analysis (PCA) identifying spatial covariance patterns. SSM/PCA pattern expression strengths were tested for their ability to predict amyloid status in a receiver-operating-characteristic analysis and validated with a leave-one-out approach. Results: Pattern expression strengths predicted amyloid status with a sensitivity of 0.94 and a specificity of 0.83. A support vector machine classification based on pattern expression strengths in 2 different SSM/PCA components yielded a prediction accuracy of 98%. Anatomically, prediction performance was driven by parietooccipital gray matter in amyloid-positive patients versus predominant white matter binding in amyloid-negative patients. Conclusion: SSM/PCA-derived binding patterns of 18F-flortaucipir differentiate between amyloid-positive and -negative neurodegenerative diseases with high accuracy. 18F-flortaucipir PET alone may convey additional information equivalent to that from amyloid PET. Together with a perfusion-weighted early-phase acquisition (18F-FDG PET-equivalent), a single scan potentially contains comprehensive information on amyloid (A), tau (T), and neurodegeneration (N) status as required by recent biomarker classification algorithms (A/T/N).
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Affiliation(s)
- Jochen Hammes
- Multimodal Neuroimaging, Department of Nuclear Medicine, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany .,Radiologische Allianz, Hamburg, Germany
| | - Gérard N Bischof
- Multimodal Neuroimaging, Department of Nuclear Medicine, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany.,Faculty of Mathematics and Natural Sciences, University of Cologne, Cologne, Germany
| | - Karl P Bohn
- Multimodal Neuroimaging, Department of Nuclear Medicine, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany.,Department of Nuclear Medicine, Inselspital University Hospital, University of Bern, Bern, Switzerland
| | - Özgür Onur
- Department of Neurology, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany.,Cognitive Neuroscience (INM-3), Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany
| | - Anja Schneider
- German Center for Neurodegenerative Diseases, Bonn and Cologne, Germany.,Department of Neurodegenerative Diseases and Geriatric Psychiatry, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Klaus Fliessbach
- German Center for Neurodegenerative Diseases, Bonn and Cologne, Germany.,Department of Neurodegenerative Diseases and Geriatric Psychiatry, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Merle C Hönig
- Multimodal Neuroimaging, Department of Nuclear Medicine, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany.,Molecular Organization of the Brain (INM-2), Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany
| | - Frank Jessen
- German Center for Neurodegenerative Diseases, Bonn and Cologne, Germany.,Department of Psychiatry, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany; and
| | - Bernd Neumaier
- Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany, and Institute of Radiochemistry and Experimental Molecular Imaging, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany
| | - Alexander Drzezga
- Multimodal Neuroimaging, Department of Nuclear Medicine, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany.,German Center for Neurodegenerative Diseases, Bonn and Cologne, Germany.,Molecular Organization of the Brain (INM-2), Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany
| | - Thilo van Eimeren
- Multimodal Neuroimaging, Department of Nuclear Medicine, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany.,Department of Neurology, University Hospital and Medical Faculty, University of Cologne, Cologne, Germany.,German Center for Neurodegenerative Diseases, Bonn and Cologne, Germany
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18
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Pontecorvo MJ, Keene CD, Beach TG, Montine TJ, Arora AK, Devous MD, Navitsky M, Kennedy I, Joshi AD, Lu M, Serrano GE, Sue LI, Intorcia AJ, Rose SE, Wilson A, Hellstern L, Coleman N, Flitter M, Aldea P, Fleisher AS, Mintun MA, Siderowf A. Comparison of regional flortaucipir PET with quantitative tau immunohistochemistry in three subjects with Alzheimer's disease pathology: a clinicopathological study. EJNMMI Res 2020; 10:65. [PMID: 32542468 PMCID: PMC7295920 DOI: 10.1186/s13550-020-00653-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 06/03/2020] [Indexed: 01/16/2023] Open
Abstract
Background The objective of this study was to make a quantitative comparison of flortaucipir PET retention with pathological tau and β-amyloid across a range of brain regions at autopsy. Methods Patients with dementia (two with clinical diagnosis of AD, one undetermined), nearing the end of life, underwent 20-min PET, beginning 80 min after an injection of ~370 mBq flortaucipir [18F]. Neocortical, basal ganglia, and limbic tissue samples were obtained bilaterally from 19 regions at autopsy and subject-specific PET regions of interest corresponding to the 19 sampled target tissue regions in each hemisphere were hand drawn on the PET images. SUVr values were calculated for each region using a cerebellar reference region. Abnormally phosphorylated tau (Ptau) and amyloid-β (Aβ) tissue concentrations were measured for each tissue region with an antibody capture assay (Histelide) using AT8 and H31L21 antibodies respectively. Results The imaging-to-autopsy interval ranged from 4–29 days. All three subjects had intermediate to high levels of AD neuropathologic change at autopsy. Mean cortical SUVr averaged across all three subjects correlated significantly with the Ptau immunoassay (Pearson r = 0.81; p < 0.0001). When Ptau and Aβ1-42 were both included in the model, the Ptau correlation with flortaucipir SUVr was preserved but there was no correlation of Aβ1-42 with flortaucipir. There was also a modest correlation between limbic (hippocampal/entorhinal and amygdala) flortaucipir SUVr and Ptau (Pearson r = 0.52; p < 0.080). There was no significant correlation between SUVr and Ptau in basal ganglia. Conclusions The results of this pilot study support a quantitative relationship between cortical flortaucipir SUVr values and quantitative measures of Ptau at autopsy. Additional research including more cases is needed to confirm the generalizability of these results. Trial registration, NIH Clinicaltrials.gov NCT # 02516046. Registered August 27, 2015. https://clinicaltrials.gov/ct2/show/NCT02516046?term=02516046&draw=2&rank=1
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Affiliation(s)
- Michael J Pontecorvo
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA.
| | - C Dirk Keene
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Thomas G Beach
- Civin Laboratory for Neuropathology, Banner Sun Health Research Institute, Phoenix, AZ, USA
| | | | - Anupa K Arora
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA
| | - Michael D Devous
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA
| | - Michael Navitsky
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA
| | - Ian Kennedy
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA
| | - Abhinay D Joshi
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA.,Present Address: Medpace Holdings, Inc., Cincinnati, Ohio, USA
| | - Ming Lu
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA
| | - Geidy E Serrano
- Civin Laboratory for Neuropathology, Banner Sun Health Research Institute, Phoenix, AZ, USA
| | - Lucia I Sue
- Civin Laboratory for Neuropathology, Banner Sun Health Research Institute, Phoenix, AZ, USA
| | - Anthony J Intorcia
- Civin Laboratory for Neuropathology, Banner Sun Health Research Institute, Phoenix, AZ, USA
| | - Shannon E Rose
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Angela Wilson
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Leanne Hellstern
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Natalie Coleman
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Matthew Flitter
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA
| | - Patricia Aldea
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA
| | - Adam S Fleisher
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA
| | - Mark A Mintun
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA
| | - Andrew Siderowf
- Avid Radiopharmaceuticals, 3711 Market St., 7th floor, Philadelphia, PA, 19104, USA.,Present Address: Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
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19
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Bevan-Jones WR, Cope TE, Jones PS, Kaalund SS, Passamonti L, Allinson K, Green O, Hong YT, Fryer TD, Arnold R, Coles JP, Aigbirhio FI, Larner AJ, Patterson K, O’Brien JT, Rowe JB. Neuroinflammation and protein aggregation co-localize across the frontotemporal dementia spectrum. Brain 2020; 143:1010-1026. [PMID: 32179883 PMCID: PMC7089669 DOI: 10.1093/brain/awaa033] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 12/04/2019] [Accepted: 01/06/2020] [Indexed: 12/14/2022] Open
Abstract
The clinical syndromes of frontotemporal dementia are clinically and neuropathologically heterogeneous, but processes such as neuroinflammation may be common across the disease spectrum. We investigated how neuroinflammation relates to the localization of tau and TDP-43 pathology, and to the heterogeneity of clinical disease. We used PET in vivo with (i) 11C-PK-11195, a marker of activated microglia and a proxy index of neuroinflammation; and (ii) 18F-AV-1451, a radioligand with increased binding to pathologically affected regions in tauopathies and TDP-43-related disease, and which is used as a surrogate marker of non-amyloid-β protein aggregation. We assessed 31 patients with frontotemporal dementia (10 with behavioural variant, 11 with the semantic variant and 10 with the non-fluent variant), 28 of whom underwent both 18F-AV-1451 and 11C-PK-11195 PET, and matched control subjects (14 for 18F-AV-1451 and 15 for 11C-PK-11195). We used a univariate region of interest analysis, a paired correlation analysis of the regional relationship between binding distributions of the two ligands, a principal component analysis of the spatial distributions of binding, and a multivariate analysis of the distribution of binding that explicitly controls for individual differences in ligand affinity for TDP-43 and different tau isoforms. We found significant group-wise differences in 11C-PK-11195 binding between each patient group and controls in frontotemporal regions, in both a regions-of-interest analysis and in the comparison of principal spatial components of binding. 18F-AV-1451 binding was increased in semantic variant primary progressive aphasia compared to controls in the temporal regions, and both semantic variant primary progressive aphasia and behavioural variant frontotemporal dementia differed from controls in the expression of principal spatial components of binding, across temporal and frontotemporal cortex, respectively. There was a strong positive correlation between 11C-PK-11195 and 18F-AV-1451 uptake in all disease groups, across widespread cortical regions. We confirmed this association with post-mortem quantification in 12 brains, demonstrating strong associations between the regional densities of microglia and neuropathology in FTLD-TDP (A), FTLD-TDP (C), and FTLD-Pick's. This was driven by amoeboid (activated) microglia, with no change in the density of ramified (sessile) microglia. The multivariate distribution of 11C-PK-11195 binding related better to clinical heterogeneity than did 18F-AV-1451: distinct spatial modes of neuroinflammation were associated with different frontotemporal dementia syndromes and supported accurate classification of participants. These in vivo findings indicate a close association between neuroinflammation and protein aggregation in frontotemporal dementia. The inflammatory component may be important in shaping the clinical and neuropathological patterns of the diverse clinical syndromes of frontotemporal dementia.
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Affiliation(s)
| | - Thomas E Cope
- Cambridge University Department of Clinical Neurosciences and Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
| | - P Simon Jones
- Cambridge University Department of Clinical Neurosciences and Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Sanne S Kaalund
- Cambridge University Department of Clinical Neurosciences and Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Luca Passamonti
- Cambridge University Department of Clinical Neurosciences and Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Istituto di Bioimmagini e Fisiologia Molecolare (IBFM), Consiglio Nazionale delle Ricerche (CNR), via Fratelli Cervi, Milano, Italy
| | - Kieren Allinson
- Department of Pathology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridge, UK
| | - Oliver Green
- Istituto di Bioimmagini e Fisiologia Molecolare (IBFM), Consiglio Nazionale delle Ricerche (CNR), via Fratelli Cervi, Milano, Italy
| | - Young T Hong
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | - Tim D Fryer
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | - Robert Arnold
- Department of Psychiatry, University of Cambridge, Cambridge, UK
| | | | | | | | - Karalyn Patterson
- Cambridge University Department of Clinical Neurosciences and Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
| | - John T O’Brien
- Department of Psychiatry, University of Cambridge, Cambridge, UK
| | - James B Rowe
- Cambridge University Department of Clinical Neurosciences and Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
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21
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Schaeverbeke J, Celen S, Cornelis J, Ronisz A, Serdons K, Van Laere K, Thal DR, Tousseyn T, Bormans G, Vandenberghe R. Binding of [ 18F]AV1451 in post mortem brain slices of semantic variant primary progressive aphasia patients. Eur J Nucl Med Mol Imaging 2019; 47:1949-1960. [PMID: 31848674 PMCID: PMC7300115 DOI: 10.1007/s00259-019-04631-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 11/18/2019] [Indexed: 12/31/2022]
Abstract
Purpose In vivo tau-PET tracer retention in the anterior temporal lobe of patients with semantic variant primary progressive aphasia (SV PPA) has consistently been reported. This is unexpected as the majority of these patients have frontotemporal lobar degeneration TDP (FTLD-TDP). Methods We conducted an in vitro [18F]AV1451 autoradiography binding study in five cases with a clinical diagnosis of SV PPA constituting the range of pathologies (i.e., three FTLD-TDP, one Alzheimer’s disease (AD), and one Pick’s disease (PiD)). Binding was compared with two controls without neurodegeneration, two typical AD, one corticobasal syndrome with underlying AD, and one frontotemporal dementia behavioral variant with FTLD-TDP. The effect of blocking with the authentic reference material and with the MAO-B inhibitor deprenyl was assessed. Immunohistochemistry was performed on adjacent cryosections. Results Absence of specific [18F]AV1451 binding was observed for all three SV PPA FTLD-TDP cases. The absence of binding in controls as well as the successful blocking with authentic AV1451 in cases with tauopathy demonstrated specificity of the [18F]AV1451 signal for tau. The specific [18F]AV1451 binding was highest in AD, followed by PiD. This binding colocalized with the respective tau lesions and could not be blocked by deprenyl. Similar pilot findings were obtained with [18F]THK5351. Conclusion In vitro autoradiography showed no [18F]AV1451 binding in SV PPA due to FTLD-TDP, while specific binding was present in SV PPA due to AD and PiD. The discrepancy between in vitro and in vivo findings remains to be explained. The discordance is not related to [18F]AV1451 idiosyncrasies as [18F]THK5351 findings were similar. Electronic supplementary material The online version of this article (10.1007/s00259-019-04631-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jolien Schaeverbeke
- Laboratory for Cognitive Neurology, Department of Neurosciences, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Sofie Celen
- Laboratory of Radiopharmaceutical Research, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Julie Cornelis
- Laboratory of Radiopharmaceutical Research, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Alicja Ronisz
- Laboratory for Pathology, Department of Imaging and Pathology, KU Leuven, Herestraat 49, 3000, Leuven, Belgium.,Leuven Brain Institute, Herestraat 49, 3000, Leuven, Belgium
| | - Kim Serdons
- Nuclear Medicine and Molecular Imaging, University HospitalsLeuven, Herestraat 49, 3000, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, University HospitalsLeuven, Herestraat 49, 3000, Leuven, Belgium
| | - Dietmar Rudolf Thal
- Laboratory for Pathology, Department of Imaging and Pathology, KU Leuven, Herestraat 49, 3000, Leuven, Belgium.,Leuven Brain Institute, Herestraat 49, 3000, Leuven, Belgium.,Pathology division, Department of Pathology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Thomas Tousseyn
- Laboratory for Pathology, Department of Imaging and Pathology, KU Leuven, Herestraat 49, 3000, Leuven, Belgium.,Pathology division, Department of Pathology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Guy Bormans
- Laboratory of Radiopharmaceutical Research, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Rik Vandenberghe
- Laboratory for Cognitive Neurology, Department of Neurosciences, KU Leuven, Herestraat 49, 3000, Leuven, Belgium. .,Neurology division, Department of Neurology, University Hospitals Leuven, Herestraat 49 box 7003, 3000, Leuven, Belgium.
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22
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Lagarde J, Olivieri P, Caillé F, Gervais P, Baron JC, Bottlaender M, Sarazin M. [18F]-AV-1451 tau PET imaging in Alzheimer’s disease and suspected non-AD tauopathies using a late acquisition time window. J Neurol 2019; 266:3087-3097. [DOI: 10.1007/s00415-019-09530-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 09/04/2019] [Accepted: 09/06/2019] [Indexed: 01/12/2023]
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Matsuda H, Shigemoto Y, Sato N. Neuroimaging of Alzheimer's disease: focus on amyloid and tau PET. Jpn J Radiol 2019; 37:735-749. [PMID: 31493197 DOI: 10.1007/s11604-019-00867-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 08/28/2019] [Indexed: 12/14/2022]
Abstract
Although the diagnosis of dementia is still largely a clinical one, based on history and disease course, neuroimaging has dramatically increased our ability to accurately diagnose it. Neuroimaging modalities now play a wider role in dementia beyond their traditional role of excluding neurosurgical lesions and are recommended in most clinical guidelines for dementia. In addition, new neuroimaging methods facilitate the diagnosis of most neurodegenerative conditions after symptom onset and show diagnostic promise even in the very early or presymptomatic phases of some diseases. In the case of Alzheimer's disease (AD), extracellular amyloid-β (Aβ) aggregates and intracellular tau neurofibrillary tangles are the two neuropathological hallmarks of the disease. Recent molecular imaging techniques using amyloid and tau PET ligands have led to preclinical diagnosis and improved differential diagnosis as well as narrowed subject selection and treatment monitoring in clinical trials aimed at delaying or preventing the symptomatic phase of AD. This review discusses the recent progress in amyloid and tau PET imaging and the key findings achieved by the use of this molecular imaging modality related to the respective roles of Aβ and tau in AD, as well as its specific limitations.
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Affiliation(s)
- Hiroshi Matsuda
- Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo, 187-8551, Japan.
| | - Yoko Shigemoto
- Department of Radiology, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo, 187-8551, Japan
| | - Noriko Sato
- Department of Radiology, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo, 187-8551, Japan
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24
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Kim HJ, Cho H, Park S, Jang H, Ryu YH, Choi JY, Moon SH, Oh SJ, Oh M, Na DL, Lyoo CH, Kim EJ, Seeley WW, Kim JS, Choi KC, Seo SW. THK5351 and flortaucipir PET with pathological correlation in a Creutzfeldt-Jakob disease patient: a case report. BMC Neurol 2019; 19:211. [PMID: 31464590 PMCID: PMC6714095 DOI: 10.1186/s12883-019-1434-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 08/18/2019] [Indexed: 12/24/2022] Open
Abstract
Background THK5351 and flortaucipir tau ligands have high affinity for paired helical filament tau, yet diverse off-target bindings have been reported. Recent data support the hypothesis that THK5351 binds to monoamine oxidase B (MAO-B) expressed from reactive astrocytes and that flortaucipir has an affinity toward MAO-A and B; however, pathological evidence is lacking. We performed a head-to-head comparison of the two tau ligands in a sporadic Creutzfeldt-Jakob disease (CJD) patient and performed an imaging-pathological correlation study. Case presentation A 67-year-old man visited our clinic a history of 6 months of rapidly progressive dementia, visual disturbance, and akinetic mutism. Diffusion-weighted imaging showed cortical diffusion restrictions in the left temporo-parieto-occipital regions. 18F-THK5351 PET, but not 18F-flortaucipir PET showed high uptake in the left temporo-parieto-occipital regions, largely overlapping with the diffusion restricted areas. Cerebrospinal fluid analysis was weakly positive for 14–3-3 protein and pathogenic prion protein was found. The patient showed rapid cognitive decline along with myoclonic seizures and died 13 months after his first visit. A post-mortem study revealed immunoreactivity for PrPsc, no evidence of neurofibrillary tangles, and abundant astrocytosis which was reactive for MAO-B antibody. Conclusions Our findings add pathological evidence that increased THK5351 uptake in sporadic CJD patients might be caused by an off-target binding driven by its high affinity for MAO-B. Electronic supplementary material The online version of this article (10.1186/s12883-019-1434-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hee Jin Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul, 135-710, Republic of Korea.,Samsung Alzheimer Research Center, Samsung Medical Center, Seoul, Korea.,Neuroscience Center, Samsung Medical Center, Seoul, Korea
| | - Hanna Cho
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Seongbeom Park
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul, 135-710, Republic of Korea.,Samsung Alzheimer Research Center, Samsung Medical Center, Seoul, Korea.,Neuroscience Center, Samsung Medical Center, Seoul, Korea
| | - Hyemin Jang
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul, 135-710, Republic of Korea.,Samsung Alzheimer Research Center, Samsung Medical Center, Seoul, Korea.,Neuroscience Center, Samsung Medical Center, Seoul, Korea
| | - Young Hoon Ryu
- Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Jae Yong Choi
- Division of RI-Convergence Research, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea
| | - Seung Hwan Moon
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Seung Jun Oh
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Minyoung Oh
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Duk L Na
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul, 135-710, Republic of Korea.,Samsung Alzheimer Research Center, Samsung Medical Center, Seoul, Korea.,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea
| | - Chul Hyoung Lyoo
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Eun-Joo Kim
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Busan, Republic of Korea
| | - William W Seeley
- Department of Neurology and Department of Pathology, University of California, San Francisco, CA, USA
| | - Jae Seung Kim
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Kyung Chan Choi
- Department of Pathology, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, Korea. .,Korea CJD Autopsy Center, Hallym University Sacred Heart Hospital, Anyang, Korea.
| | - Sang Won Seo
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul, 135-710, Republic of Korea. .,Samsung Alzheimer Research Center, Samsung Medical Center, Seoul, Korea. .,Department of Clinical Research Design and Evaluation, SAIHST, Sungkyunkwan University, Seoul, Korea. .,Center for Clinical Epidemiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
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Drake LR, Pham JM, Desmond TJ, Mossine AV, Lee SJ, Kilbourn MR, Koeppe RA, Brooks AF, Scott PJ. Identification of AV-1451 as a Weak, Nonselective Inhibitor of Monoamine Oxidase. ACS Chem Neurosci 2019; 10:3839-3846. [PMID: 31339297 DOI: 10.1021/acschemneuro.9b00326] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
[18F]AV-1451 is one of the most widely used radiotracers for positron emission tomography (PET) imaging of tau protein aggregates in neurodegenerative disorders. While the radiotracer binds with high affinity to tau neurofibrillary tangles, extensive clinical studies have simultaneously revealed off-target tracer accumulation in areas of low tau burden such as the basal ganglia and choroid plexus. Though there are a number of possible reasons for this accumulation, it is often attributed to off-target binding to monoamine oxidase (MAO). In this paper, we investigate the association between [18F]AV-1451 and MAO through (i) enzyme inhibition assays, (ii) autoradiography with postmortem tissue samples, and (iii) nonhuman primate PET imaging. We confirm that [18F]AV-1451 is a weak inhibitor of MAO-A and -B and that MAO inhibitors can alter binding of [18F]AV-1451 in autoradiography and in vivo PET imaging.
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Affiliation(s)
- Lindsey R. Drake
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jonathan M. Pham
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Timothy J. Desmond
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Andrew V. Mossine
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - So Jeong Lee
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Michael R. Kilbourn
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Robert A. Koeppe
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Allen F. Brooks
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Peter J.H. Scott
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
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26
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AD molecular: Imaging tau aggregates with positron emissions tomography. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 165:107-138. [PMID: 31481160 DOI: 10.1016/bs.pmbts.2019.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Pathologic aggregates of tau protein are observed in several neurodegenerative diseases and are used to diagnose and stage disease postmortem. Recent advances in positron emission tomography radioligands allow for the detection of aggregated tau proteins in living persons. This chapter describes the development and characterization of several positron emission tomography radioligands used to detect tau pathophysiology in vivo, and how these ligands are being used in clinical aging and neurodegenerative disease research with a focus on imaging tau aggregates in Alzheimer's disease.
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27
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Wooten DW, Ortiz-Terán L, Zubcevik N, Zhang X, Huang C, Sepulcre J, Atassi N, Johnson KA, Zafonte RD, El Fakhri G. Multi-Modal Signatures of Tau Pathology, Neuronal Fiber Integrity, and Functional Connectivity in Traumatic Brain Injury. J Neurotrauma 2019; 36:3233-3243. [PMID: 31210098 DOI: 10.1089/neu.2018.6178] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
[18F]AV-1451 (aka 18F-Flortaucipir, [18F]T807) was developed for positron-emission tomography (PET) imaging of paired helical filaments of hyperphosphorylated tau, which are of interest in a range of neuropathologies, including traumatic brain injury (TBI). Magnetic resonance imaging (MRI) techniques like diffusion tensor imaging (DTI) and resting state functional connectivity assess structural and functional characteristics of the brain, complementing the molecular information that can be obtained by PET. The goal herein was to explore the utility of such multi-modal imaging in a case series based on a population of TBI subjects. This study probes the interrelationship between tau deposition, white matter integrity, and gray matter functional connectivity across the spectrum of TBI. Nineteen subjects (11 controls, five former contact sports athletes, one automotive accident, and two with military-related injury) underwent [18F]AV-1451 PET and magnetic resonance scanning procedures. [18F]AV-1451 distribution volume ratio (DVR) was estimated using the Logan method and the cerebellum as a reference region. Diffusion tractography images and fractional anisotropy (FA) images were generated using diffusion toolkit and FSL. Resting-state functional MRI (fMRI) analysis was based on a graph theory metric, namely weighted degree centrality. TBI subjects showed greater heterogeneity in [18F]AV-1451 DVR when compared with control subjects. In a subset of TBI subjects, areas with high [18F]AV-1451 binding corresponded with increased FA and diminished white matter tract density in DTI. Functional MRI results exhibited an increase in functional connectivity, particularly among local connections, in the areas where tau aggregates were more prevalent. In a case series of a diverse group of TBI subjects, brain regions with elevated tau burden exhibited increased functional connectivity as well as decreased white matter integrity. These findings portray molecular, microstructural, and functional corollaries of TBI that spatially coincide and can be measured in the living human brain using noninvasive neuroimaging techniques.
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Affiliation(s)
- Dustin W Wooten
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Laura Ortiz-Terán
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Nevena Zubcevik
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Massachusetts General Hospital, Brigham and Women's Hospital Harvard Medical School, Charlestown, Massachusetts
| | - Xiaomeng Zhang
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Chuan Huang
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jorge Sepulcre
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Nazem Atassi
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Keith A Johnson
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.,Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ross D Zafonte
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Massachusetts General Hospital, Brigham and Women's Hospital Harvard Medical School, Charlestown, Massachusetts
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Pascual B, Funk Q, Zanotti-Fregonara P, Pal N, Rockers E, Yu M, Spann B, Román GC, Schulz PE, Karmonik C, Appel SH, Masdeu JC. Multimodal 18F-AV-1451 and MRI Findings in Nonfluent Variant of Primary Progressive Aphasia: Possible Insights on Nodal Propagation of Tau Protein Across the Syntactic Network. J Nucl Med 2019; 61:263-269. [PMID: 31350322 DOI: 10.2967/jnumed.118.225508] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 07/06/2019] [Indexed: 11/16/2022] Open
Abstract
Although abnormally folded tau protein has been found to self-propagate from neuron to connected neuron, similar propagation through human brain networks has not been fully documented. We studied tau propagation in the left hemispheric syntactic network, which comprises an anterior frontal node and a posterior temporal node connected by the white matter of the left arcuate fasciculus. This network is affected in the nonfluent variant of primary progressive aphasia, a neurodegenerative disorder with tau accumulation. Methods: Eight patients with the nonfluent variant of primary progressive aphasia (age, 67.0 ± 7.4 y; 4 women) and 8 healthy controls (age, 69.6 ± 7.0 y; 4 women) were scanned with 18F-AV-1451 tau PET to determine tau deposition in the brain and with MRI to determine the fractional anisotropy of the arcuate fasciculus. Normal syntactic network characteristics were confirmed with structural MRI diffusion imaging in our healthy controls and with blood oxygenation level-dependent functional imaging in 35 healthy participants from the Alzheimer Disease Neuroimaging Initiative database. Results: Language scores in patients indicated dysfunction of the anterior node. 18F-AV-1451 deposition was greatest in the 2 nodes of the syntactic network. The left arcuate fasciculus had decreased fractional anisotropy, particularly near the anterior node. Normal MRI structural connectivity from an area similar to the one containing tau in the anterior frontal node projected to an area similar to the one containing tau in the patients in the posterior temporal node. Conclusion: Tau accumulation likely started in the more affected anterior node and, at the disease stage at which we studied these patients, appeared as well in the brain region (in the temporal lobe) spatially separate from but most connected with it. The arcuate fasciculus, connecting both of them, was most severely affected anteriorly, as would correspond to a loss of axons from the anterior node. These findings are suggestive of tau propagation from node to connected node in a natural human brain network and support the idea that neurons that wire together die together.
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Affiliation(s)
- Belen Pascual
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas
| | - Quentin Funk
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas
| | - Paolo Zanotti-Fregonara
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas
| | - Neha Pal
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas
| | - Elijah Rockers
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas
| | - Meixiang Yu
- Cyclotron and Radiopharmaceutical Core, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas
| | - Bryan Spann
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas
| | - Gustavo C Román
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas
| | | | - Christof Karmonik
- MRI Core, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas; and
| | - Stanley H Appel
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas
| | - Joseph C Masdeu
- Nantz National Alzheimer Center, Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas
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Perani D, Iaccarino L, Lammertsma AA, Windhorst AD, Edison P, Boellaard R, Hansson O, Nordberg A, Jacobs AH. A new perspective for advanced positron emission tomography-based molecular imaging in neurodegenerative proteinopathies. Alzheimers Dement 2019; 15:1081-1103. [PMID: 31230910 DOI: 10.1016/j.jalz.2019.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/21/2019] [Accepted: 02/20/2019] [Indexed: 12/12/2022]
Abstract
Recent studies in neurodegenerative conditions have increasingly highlighted that the same neuropathology can trigger different clinical phenotypes or, vice-versa, that similar phenotypes can be triggered by different neuropathologies. This evidence has called for the adoption of a pathology spectrum-based approach to study neurodegenerative proteinopathies. These conditions share brain deposition of abnormal protein aggregates, leading to aberrant biochemical, metabolic, functional, and structural changes. Positron emission tomography (PET) is a well-recognized and unique tool for the in vivo assessment of brain neuropathology, and novel PET techniques are emerging for the study of specific protein species. Today, key applications of PET range from early research and clinical diagnostic tools to their use in clinical trials for both participants screening and outcome evaluation. This position article critically reviews the role of distinct PET molecular tracers for different neurodegenerative proteinopathies, highlighting their strengths, weaknesses, and opportunities, with special emphasis on methodological challenges and future applications.
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Affiliation(s)
- Daniela Perani
- Vita-Salute San Raffaele University, Nuclear Medicine Unit San Raffaele Hospital, Division of Neuroscience San Raffaele Scientific Institute, Milan, Italy
| | - Leonardo Iaccarino
- Vita-Salute San Raffaele University, Nuclear Medicine Unit San Raffaele Hospital, Division of Neuroscience San Raffaele Scientific Institute, Milan, Italy
| | - Adriaan A Lammertsma
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Albert D Windhorst
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Paul Edison
- Division of Brain Sciences, Department of Medicine, Imperial College London, London, UK; Neurology Imaging Unit, Imperial College London, London, UK
| | - Ronald Boellaard
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Lund, Sweden; Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Center for Alzheimer Research, Stockholm, Sweden
| | - Andreas H Jacobs
- European Institute for Molecular Imaging, University of Münster, Münster, Germany; Evangelische Kliniken Bonn gGmbH, Johanniter Krankenhaus, Bonn, Germany.
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Smith R, Santillo AF, Waldö ML, Strandberg O, Berron D, Vestberg S, van Westen D, van Swieten J, Honer M, Hansson O. 18F-Flortaucipir in TDP-43 associated frontotemporal dementia. Sci Rep 2019; 9:6082. [PMID: 30988363 PMCID: PMC6465310 DOI: 10.1038/s41598-019-42625-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 04/01/2019] [Indexed: 12/13/2022] Open
Abstract
Retention of 18F-Flortaucipir is reportedly increased in the semantic variant of primary progressive aphasia (svPPA), which is dominated by TDP-43 pathology. However, it is unclear if 18F-Flortaucipir is also increased in other TDP-43 diseases, such as bvFTD caused by a C9orf72 gene mutation. We therefore recruited six C9orf72 expansion carriers, six svPPA patients, and 54 healthy controls. All underwent 18F-Flortaucipir PET and MRI scanning. Data from 39 Alzheimer’s Disease patients were used for comparison. PET tracer retention was assessed both at the region-of-interest (ROI) and at the voxel-level. Further, autoradiography using 3H-Flortaucipir was performed. SvPPA patients exhibited higher 18F-Flortaucipir retention in the lateral temporal cortex bilaterally according to ROI- and voxel-based analyses. In C9orf72 patients, 18F-Flortaucipir binding was slightly increased in the inferior frontal lobes in the ROI based analysis, but these results were not replicated in the voxel-based analysis. Autoradiography did not show specific binding in svPPA cases or in C9orf72-mutation carriers. In conclusion, temporal lobe 18F-Flortaucipir retention was observed in some cases of svPPA, but the uptake was of a lower magnitude compared to AD dementia. C9orf72-mutation carriers exhibited none or limited 18F-Flortaucipir retention, indicating that 18F-Flortaucipir binding in TDP-43 proteinopathies is not a general TDP-43 related phenomenon.
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Affiliation(s)
- R Smith
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Lund, Sweden. .,Department of Neurology, Skåne University Hospital, Lund, Sweden.
| | - A F Santillo
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Lund, Sweden
| | - M Landqvist Waldö
- Clinical Sciences Helsingborg, Department of Clinical Sciences, Lund, Lund University, Lund, Sweden
| | - O Strandberg
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Lund, Sweden
| | - D Berron
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Lund, Sweden
| | - S Vestberg
- Department of Psychology, Lund University, Lund, Sweden
| | - D van Westen
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Lund, Sweden
| | - J van Swieten
- Department of Neurology, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - M Honer
- Roche Pharmaceutical Research and Early Development, Neuroscience Translational Technologies, Roche Innovation Center, Basel, Switzerland
| | - O Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Lund, Sweden. .,Memory Clinic, Skåne University Hospital, Malmö, Sweden.
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Lois C, Gonzalez I, Johnson KA, Price JC. PET imaging of tau protein targets: a methodology perspective. Brain Imaging Behav 2019; 13:333-344. [PMID: 29497982 PMCID: PMC6119534 DOI: 10.1007/s11682-018-9847-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The two neuropathological hallmarks of Alzheimer's disease (AD) are amyloid-[Formula: see text] plaques and neurofibrillary tangles of tau protein. Fifteen years ago, Positron Emission Tomography (PET) with Pittsburgh Compound B (11C-PiB) enabled selective in-vivo visualization of amyloid-[Formula: see text] plaque deposits and has since provided valuable information about the role of amyloid-[Formula: see text] deposition in AD. The progression of tau deposition has been shown to be highly associated with neuronal loss, neurodegeneration, and cognitive decline. Until recently it was not possible to visualize tau deposition in-vivo, but several tau PET tracers are now available in different stages of clinical development. To date, no tau tracer has been approved by the Food and Drug Administration for use in the evaluation of AD or other tauopathies, despite very active research efforts. In this paper we review the recent developments in tau PET imaging with a focus on in-vivo findings in AD and discuss the challenges associated with tau tracer development, the status of development and validation of different tau tracers, and the clinical information these provide.
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Affiliation(s)
- Cristina Lois
- Gordon Center for Medical Imaging, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital / Harvard Medical School, Boston, MA, USA.
| | - Ivan Gonzalez
- Athinoula A. Martinos Center for Biomedical Research, Department of Radiology, Massachusetts General Hospital / Harvard Medical School, Boston, MA, USA
| | - Keith A Johnson
- Gordon Center for Medical Imaging, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital / Harvard Medical School, Boston, MA, USA
| | - Julie C Price
- Athinoula A. Martinos Center for Biomedical Research, Department of Radiology, Massachusetts General Hospital / Harvard Medical School, Boston, MA, USA
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Cross-interaction of tau PET tracers with monoamine oxidase B: evidence from in silico modelling and in vivo imaging. Eur J Nucl Med Mol Imaging 2019; 46:1369-1382. [PMID: 30919054 PMCID: PMC6486902 DOI: 10.1007/s00259-019-04305-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 03/04/2019] [Indexed: 02/07/2023]
Abstract
Purpose Several tracers have been designed for tracking the abnormal accumulation of tau pathology in vivo. Recently, concerns have been raised about the sources of off-target binding for these tracers; inconclusive data propose binding for some tracers to monoamine oxidase B (MAO-B). Methods Molecular docking and dynamics simulations were used to estimate the affinity and free energy for the binding of several tau tracers (FDDNP, THK523, THK5105, THK5317, THK5351, T807 [aka AV-1451, flortaucipir], T808, PBB3, RO-948, MK-6240, JNJ-311 and PI-2620) to MAO-B. These values were then compared with those for safinamide (MAO-B inhibitor). PET imaging was used with the tau tracer [18F]THK5317 and the MAO-B tracer [11C]DED in five patients with Alzheimer’s disease to investigate the MAO-B binding component of this first generation tau tracer in vivo. Results The computational modelling studies identified a binding site for all the tau tracers on MAO-B; this was the same site as that for safinamide. The binding affinity and free energy of binding for the tau tracers to MAO-B was substantial and in a similar range to those for safinamide. The most recently developed tau tracers MK-6240, JNJ-311 and PI-2620 appeared, in silico, to have the lowest relative affinity for MAO-B. The in vivo investigations found that the regional distribution of binding for [18F]THK5317 was different from that for [11C]DED, although areas of suspected off-target [18F]THK5317 binding were detected. The binding relationship between [18F]THK5317 and [11C]DED depended on the availability of the MAO-B enzyme. Conclusions The developed tau tracers show in silico and in vivo evidence of cross-interaction with MAO-B; the MAO-B component of the tracer binding was dependent on the regional concentration of the enzyme. Electronic supplementary material The online version of this article (10.1007/s00259-019-04305-8) contains supplementary material, which is available to authorized users.
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Baker SL, Harrison TM, Maass A, La Joie R, Jagust WJ. Effect of Off-Target Binding on 18F-Flortaucipir Variability in Healthy Controls Across the Life Span. J Nucl Med 2019; 60:1444-1451. [PMID: 30877180 DOI: 10.2967/jnumed.118.224113] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/20/2019] [Indexed: 02/04/2023] Open
Abstract
Measuring early tau accumulation is important in studying aging and Alzheimer disease and is only as accurate as the signal-to-noise ratio of the tracer. Along with aggregated tau in the form of neurofibrillary tangles, 18F-flortaucipir has been reported to bind to neuromelanin, monoamine oxidase, calcifications, iron, leptomeningeal melanocytes, and microhemorrages. Although 18F-flortaucipir successfully differentiates healthy controls (HCs) from subjects with Alzheimer disease, variability exists in the cortical signal in amyloid-negative HCs. We aimed to explore the relationship between off-target binding signal and variability in the cortical signal in HCs. Methods: Subjects (n = 139) received 11C-Pittsburgh compound B (PIB) and 18F-flortaucipir PET scans and a magnetization-prepared rapid gradient echo MRI scan. PET frames were realigned and coregistered to the MR images, which were segmented using FreeSurfer. In amyloid-negative HCs (n = 90; age range, 21-94 y), 7 nonspecific or off-target binding regions were considered: caudate, pallidum, putamen, thalamus, cerebellar white matter, hemispheric white matter, and choroid plexus. These regions of interest were assigned to 3 similarly behaving groups using principle components analysis, exploratory factor analysis, and Pearson correlations for caudate, putamen, and pallidum (also correlated with age); thalamus and white matter; and choroid plexus. In amyloid-negative HCs with 11C-PIB and 18F-flortaucipir scans, correlations were calculated between white and gray matter before and after partial-volume correction. Results: The correlation between white and gray matter disappeared after partial-volume correction in 11C-PIB (r 2 = 0) but persisted for 18F-flortaucipir (r 2 = 0.27), demonstrating that the correlation between white and gray matter signal in 18F-flortaucipir is not solely due to partial-volume effects. A linear regression showed that off-target signal from putamen and thalamus together explained 64% of the variability in the cortical signal in amyloid-negative HCs (not seen in amyloid-positive HCs). Variability in amyloid-negative HCs but not amyloid-positive HCs correlated with white matter signal (unrelated to partial-volume effects) and age-related off-target signal (possibly related to iron load). Conclusion: The noise in the 18F-flortaucipir measurement could pose challenges when studying early tau accumulation.
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Affiliation(s)
| | - Theresa M Harrison
- Helen Wills Neuroscience Institute, University of California-Berkeley, Berkeley, California
| | - Anne Maass
- Helen Wills Neuroscience Institute, University of California-Berkeley, Berkeley, California.,German Center for Neurodegenerative Diseases, Magdeburg, Germany; and
| | - Renaud La Joie
- Memory and Aging Center, University of California-San Francisco, San Francisco, California
| | - William J Jagust
- Lawrence Berkeley National Laboratory, Berkeley, California.,Helen Wills Neuroscience Institute, University of California-Berkeley, Berkeley, California
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34
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Aguero C, Dhaynaut M, Normandin MD, Amaral AC, Guehl NJ, Neelamegam R, Marquie M, Johnson KA, El Fakhri G, Frosch MP, Gomez-Isla T. Autoradiography validation of novel tau PET tracer [F-18]-MK-6240 on human postmortem brain tissue. Acta Neuropathol Commun 2019; 7:37. [PMID: 30857558 PMCID: PMC6410510 DOI: 10.1186/s40478-019-0686-6] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 02/23/2019] [Indexed: 12/13/2022] Open
Abstract
[F-18]-MK-6240, a novel tau positron emission tomography (PET) tracer recently discovered for the in vivo detection of neurofibrillary tangles, has the potential to improve diagnostic accuracy in the detection of Alzheimer disease. We have examined regional and substrate-specific binding patterns as well as possible off-target binding of this tracer on human brain tissue to advance towards its validation. We applied [F-18]-MK-6240 phosphor screen and high resolution autoradiography to postmortem samples from patients with a definite pathological diagnosis of Alzheimer disease, frontotemporal lobar degeneration-tau (Pick's disease, progressive supranuclear palsy and corticobasal degeneration), chronic traumatic encephalopathy, frontotemporal lobar degeneration-Tar DNA-binding protein 43 (TDP-43), dementia with Lewy bodies, cerebral amyloid angiopathy and elderly controls free of pathologic changes of neurodegenerative disease. We also directly compared the binding properties of [F-18]-MK-6240 and [F-18]-AV-1451 in human tissue, and examined potential nonspecific binding of both tau tracers to monoamine oxidases (MAO) by using autoradiography in the presence of selective monoamine oxidase A (MAO-A) and monoamine oxidase B (MAO-B) inhibitors. Our data indicate that MK-6240 strongly binds to neurofibrillary tangles in Alzheimer disease but does not seem to bind to a significant extent to tau aggregates in non-Alzheimer tauopathies, suggesting that it may have a limited utility for the in vivo detection of these pathologies. There is no evidence of binding to lesions containing β-amyloid, α-synuclein or TDP-43. In addition, we identified MK-6240 strong off-target binding to neuromelanin and melanin-containing cells, and some weaker binding to areas of hemorrhage. These binding patterns are nearly identical to those previously reported by our group and others for [F-18]-AV-1451. Of note, [F-18]-MK-6240 and [F-18]-AV-1451 autoradiographic binding signals were only weakly displaced by competing concentrations of selective MAO-B inhibitor deprenyl but not by MAO-A inhibitor clorgyline, suggesting that MAO enzymes do not appear to be a significant binding target of any of these two tracers. Together these novel findings provide relevant insights for the correct interpretation of in vivo [F-18]-MK-6240 PET imaging.
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Affiliation(s)
- Cinthya Aguero
- Department of Neurology, Massachusetts General Hospital, WACC, Suite 715, 15th Parkman St., Boston, MA, 02114, USA
- MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA, USA
| | - Maeva Dhaynaut
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- AP-HP, Department of Nuclear Medicine, Pitié-Salpêtrière Hospital, Sorbonne University, UPMC Paris 06, CNRS UMR 7371, INSERM U1146, 75013, Paris, France
| | - Marc D Normandin
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Ana C Amaral
- Department of Neurology, Massachusetts General Hospital, WACC, Suite 715, 15th Parkman St., Boston, MA, 02114, USA
- MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA, USA
| | - Nicolas J Guehl
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Ramesh Neelamegam
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Marta Marquie
- Department of Neurology, Massachusetts General Hospital, WACC, Suite 715, 15th Parkman St., Boston, MA, 02114, USA
- MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA, USA
| | - Keith A Johnson
- Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Georges El Fakhri
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Matthew P Frosch
- MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA, USA
- C.S. Kubik Laboratory for Neuropathology, Massachusetts General Hospital, Boston, MA, USA
| | - Teresa Gomez-Isla
- Department of Neurology, Massachusetts General Hospital, WACC, Suite 715, 15th Parkman St., Boston, MA, 02114, USA.
- MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA, USA.
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Jadhav S, Avila J, Schöll M, Kovacs GG, Kövari E, Skrabana R, Evans LD, Kontsekova E, Malawska B, de Silva R, Buee L, Zilka N. A walk through tau therapeutic strategies. Acta Neuropathol Commun 2019; 7:22. [PMID: 30767766 PMCID: PMC6376692 DOI: 10.1186/s40478-019-0664-z] [Citation(s) in RCA: 182] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/21/2019] [Indexed: 12/18/2022] Open
Abstract
Tau neuronal and glial pathologies drive the clinical presentation of Alzheimer's disease and related human tauopathies. There is a growing body of evidence indicating that pathological tau species can travel from cell to cell and spread the pathology through the brain. Throughout the last decade, physiological and pathological tau have become attractive targets for AD therapies. Several therapeutic approaches have been proposed, including the inhibition of protein kinases or protein-3-O-(N-acetyl-beta-D-glucosaminyl)-L-serine/threonine Nacetylglucosaminyl hydrolase, the inhibition of tau aggregation, active and passive immunotherapies, and tau silencing by antisense oligonucleotides. New tau therapeutics, across the board, have demonstrated the ability to prevent or reduce tau lesions and improve either cognitive or motor impairment in a variety of animal models developing neurofibrillary pathology. The most advanced strategy for the treatment of human tauopathies remains immunotherapy, which has already reached the clinical stage of drug development. Tau vaccines or humanised antibodies target a variety of tau species either in the intracellular or extracellular spaces. Some of them recognise the amino-terminus or carboxy-terminus, while others display binding abilities to the proline-rich area or microtubule binding domains. The main therapeutic foci in existing clinical trials are on Alzheimer's disease, progressive supranuclear palsy and non-fluent primary progressive aphasia. Tau therapy offers a new hope for the treatment of many fatal brain disorders. First efficacy data from clinical trials will be available by the end of this decade.
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Affiliation(s)
- Santosh Jadhav
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska 9, 845 10, Bratislava, Slovakia
- AXON Neuroscience R&D Services SE, Dvorakovo nabrezie 10, 811 02, Bratislava, Slovakia
| | - Jesus Avila
- Centro de Biologia Molecular "Severo Ochoa", Consejo Superior de Investigaciones, Cientificas, Universidad Autonoma de Madrid, C/ Nicolas Cabrera, 1. Campus de Cantoblanco, 28049, Madrid, Spain
- Networking Research Center on Neurodegenerative, Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Michael Schöll
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
- Department of, Psychiatry and Neurochemistry, University of Gothenburg, Gothenburg, Sweden
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden
- Dementia Research Centre, University College London, London, UK
| | - Gabor G Kovacs
- Institute of Neurology, Medical University of Vienna, AKH 4J, Währinger Gürtel 18-20, 1097, Vienna, Austria
| | - Enikö Kövari
- Department of Mental Health and Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
| | - Rostislav Skrabana
- AXON Neuroscience R&D Services SE, Dvorakovo nabrezie 10, 811 02, Bratislava, Slovakia
| | - Lewis D Evans
- Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QN, UK
| | - Eva Kontsekova
- AXON Neuroscience R&D Services SE, Dvorakovo nabrezie 10, 811 02, Bratislava, Slovakia
| | - Barbara Malawska
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688, Cracow, Poland
| | - Rohan de Silva
- Reta Lila Weston Institute and Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, 1 Wakefield Street, London, WC1N 1PJ, UK
| | - Luc Buee
- Universite of Lille, Inserm, CHU-Lille, UMRS1172, Alzheimer & Tauopathies, Place de Verdun, 59045, Lille cedex, France.
| | - Norbert Zilka
- AXON Neuroscience R&D Services SE, Dvorakovo nabrezie 10, 811 02, Bratislava, Slovakia.
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Schöll M, Maass A, Mattsson N, Ashton NJ, Blennow K, Zetterberg H, Jagust W. Biomarkers for tau pathology. Mol Cell Neurosci 2018; 97:18-33. [PMID: 30529601 PMCID: PMC6584358 DOI: 10.1016/j.mcn.2018.12.001] [Citation(s) in RCA: 148] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 12/01/2018] [Indexed: 12/14/2022] Open
Abstract
The aggregation of fibrils of hyperphosphorylated and C-terminally truncated microtubule-associated tau protein characterizes 80% of all dementia disorders, the most common neurodegenerative disorders. These so-called tauopathies are hitherto not curable and their diagnosis, especially at early disease stages, has traditionally proven difficult. A keystone in the diagnosis of tauopathies was the development of methods to assess levels of tau protein in vivo in cerebrospinal fluid, which has significantly improved our knowledge about these conditions. Tau proteins have also been measured in blood, but the importance of tau-related changes in blood is still unclear. The recent addition of positron emission tomography ligands to visualize, map and quantify tau pathology has further contributed with information about the temporal and spatial characteristics of tau accumulation in the living brain. Together, the measurement of tau with fluid biomarkers and positron emission tomography constitutes the basis for a highly active field of research. This review describes the current state of biomarkers for tau biomarkers derived from neuroimaging and from the analysis of bodily fluids and their roles in the detection, diagnosis and prognosis of tau-associated neurodegenerative disorders, as well as their associations with neuropathological findings, and aims to provide a perspective on how these biomarkers might be employed prospectively in research and clinical settings. Biomarkers for tau pathology are now essential to the research framework in the diagnosis of Alzheimer's disease (AD) Measurement of t- and p-tau has been possible in cerebrospinal fluid (CSF) for some time, the recent development of positron emission tomography (PET) ligands binding to tau has added the possibility to map and quantify tau in the living brain First-generation tau PET ligands bind predominantly to AD-typical 3R/4R tau isoforms and exhibit off-target binding that can limit accurate ligand uptake quantification Second-generation tau PET ligands appear to bind to comparable binding sites but exhibit fewer issues with brain off-target binding Biomarkers for tau derived from CSF analysis and PET could provide complementary information about disease state and stage At this time, T-tau, but not p-tau, can be reliably measured in plasma using ultra-sensitive immunoassays.
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Affiliation(s)
- Michael Schöll
- Wallenberg Centre for Molecular and Translational Medicine and the Department of Psychiatry and Neurochemistry, University of Gothenburg, Gothenburg, Sweden; Clinical Memory Research Unit, Lund University, Malmö, Sweden; Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.
| | - Anne Maass
- German Center for Neurodegenerative Diseases, Magdeburg, Germany; Helen Wills Neuroscience Institute, University of California, Berkeley, USA
| | - Niklas Mattsson
- Clinical Memory Research Unit, Lund University, Malmö, Sweden; Department of Neurology, Skåne University Hospital, Lund, Sweden
| | - Nicholas J Ashton
- Wallenberg Centre for Molecular and Translational Medicine and the Department of Psychiatry and Neurochemistry, University of Gothenburg, Gothenburg, Sweden; King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK; Department of Psychiatry and Neurochemistry, University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden; UK Dementia Research Institute at UCL, London, UK
| | - William Jagust
- Helen Wills Neuroscience Institute, University of California, Berkeley, USA; Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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Abstract
PURPOSE OF REVIEW Differential diagnosis of atypical Parkinson syndromes (APS) is difficult as clinical presentations may vary and as there is a strong overlap between disease entities. Aggregations of misfolded and hyperphosphorylated tau proteins are the common denominator of many of these diseases. RECENT FINDINGS Several tau targeting positron emission tomography (PET) tracers have been evaluated as possible biomarkers in APS in the recent years. For Parkinson's disease, dementia with Lewy bodies, progressive supranuclear palsy, and corticobasal degeneration, promising results have been reported with regard to the ability to detect the presence of disease and to discriminate patients from controls. However, the discussion about the specificity of the first-generation radiotracers and their value in the clinical context is ongoing. A combined interpretation of signal strength and distribution pattern in PET scans with first- and second-generation tracers may be helpful in clinical diagnosis and follow-up of patients with APS.
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38
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Harada R, Okamura N, Furumoto S, Yanai K. Imaging Protein Misfolding in the Brain Using β-Sheet Ligands. Front Neurosci 2018; 12:585. [PMID: 30186106 PMCID: PMC6110819 DOI: 10.3389/fnins.2018.00585] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 08/06/2018] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative diseases characterized by pathological protein accumulation in cells are termed “proteinopathies.” Although various protein aggregates share cross-β-sheet structures, actual conformations vary among each type of protein deposit. Recent progress in the development of radiotracers for positron emission tomography (PET) has enabled the visualization of protein aggregates in living brains. Amyloid PET tracers have been developed, and are widely used for the diagnosis of Alzheimer’s disease and non-invasive assessment of amyloid burden in clinical trials of anti-dementia drugs. Furthermore, several tau PET tracers have been successfully developed and used in the clinical studies. However, recent studies have identified the presence of off-target binding of radiotracers in areas of tau deposition, suggesting that concomitant neuroinflammatory changes might affect tracer binding. In contrast to amyloid and tau PET, there are no established tracers for imaging Lewy bodies in the human brain. In this review, we describe lessons learned from the development of PET tracers and discuss the future direction of tracer development for protein misfolding diseases.
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Affiliation(s)
- Ryuichi Harada
- Department of Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Nobuyuki Okamura
- Division of Pharmacology, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Shozo Furumoto
- Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan
| | - Kazuhiko Yanai
- Department of Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan.,Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan
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Okamura N, Harada R, Ishiki A, Kikuchi A, Nakamura T, Kudo Y. The development and validation of tau PET tracers: current status and future directions. Clin Transl Imaging 2018; 6:305-316. [PMID: 30148121 PMCID: PMC6096533 DOI: 10.1007/s40336-018-0290-y] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/03/2018] [Indexed: 01/02/2023]
Abstract
Purpose To provide an overview on positron emission tomography (PET) imaging of tau pathology in Alzheimer’s disease (AD) and other neurodegenerative disorders. Results Different classes of tau tracers such as flortaucipir, THK5317, and PBB3 have been developed and utilized in previous clinical studies. In AD, the topographical distribution of tracer binding follows the known distribution of neurofibrillary tangles and is closely associated with neurodegeneration as well as the clinical phenotype of dementia. Significant retention of tracers has also been observed in the frequent site of the 4-repeat (4R) tau isoform deposits in non-AD tauopathies, such as in progressive supranuclear palsy. However, in vitro binding studies indicate that most tau tracers are less sensitive to straight tau filaments, in contrast to their high binding affinity to paired helical filaments of tau (PHF-tau). The first-generation of tau tracers shows off-target binding in the basal ganglia, midbrain, thalamus, choroid plexus, and venous sinus. Off-target binding of THK5351 to monoamine oxidase B (MAO-B) has been observed in disease-associated brain regions linked to neurodegeneration and is associated with astrogliosis in areas of misfolded protein accumulation. The second generation of tau tracers, such as [18F]MK-6240, is highly selective to PHF-tau with little off-target binding and have enabled the reliable assessment of PHF-tau burden in aging and AD. Conclusions Tau PET tracers have enabled in vivo quantification of PHF-tau burden in human brains. Tau PET can help in understanding the underlying cause of dementia symptoms, and in patient selection for clinical trials of anti-dementia therapies.
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Affiliation(s)
- Nobuyuki Okamura
- 1Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan.,3Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Ryuichi Harada
- 2Department of Pharmacology, Tohoku University School of Medicine, Sendai, Japan
| | - Aiko Ishiki
- 3Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Akio Kikuchi
- 4Department of Neurology, Tohoku University School of Medicine, Sendai, Japan
| | - Tadaho Nakamura
- 1Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Yukitsuka Kudo
- 3Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
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Ishiki A, Harada R, Kai H, Sato N, Totsune T, Tomita N, Watanuki S, Hiraoka K, Ishikawa Y, Funaki Y, Iwata R, Furumoto S, Tashiro M, Sasano H, Kitamoto T, Kudo Y, Yanai K, Furukawa K, Okamura N, Arai H. Neuroimaging-pathological correlations of [ 18F]THK5351 PET in progressive supranuclear palsy. Acta Neuropathol Commun 2018; 6:53. [PMID: 29958546 PMCID: PMC6025736 DOI: 10.1186/s40478-018-0556-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 06/19/2018] [Indexed: 11/10/2022] Open
Abstract
Recent positron emission tomography (PET) studies have demonstrated the accumulation of tau PET tracer in the affected region of progressive supranuclear palsy (PSP) cases. To confirm the binding target of radiotracer in PSP, we performed an imaging-pathology correlation study in two autopsy-confirmed PSP patients who underwent [18F]THK5351 PET before death. One patient with PSP Richardson syndrome showed elevated tracer retention in the globus pallidus and midbrain. In a patient with PSP-progressive nonfluent aphasia, [18F]THK5351 retention also was observed in the cortical areas, particularly the temporal cortex. Neuropathological examination confirmed PSP in both patients. Regional [18F]THK5351 standardized uptake value ratio (SUVR) in antemortem PET was significantly correlated with monoamine oxidase-B (MAO-B) level, reactive astrocytes density, and tau pathology at postmortem examination. In in vitro autoradiography, specific THK5351 binding was detected in the area of antemortem [18F]THK5351 retention, and binding was blocked completely by a reversible selective MAO-B inhibitor, lazabemide, in brain samples from these patients. In conclusion, [18F]THK5351 PET signals reflect MAO-B expressing reactive astrocytes, which may be associated with tau accumulation in PSP.
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Smith R, Schöll M, Londos E, Ohlsson T, Hansson O. 18F-AV-1451 in Parkinson's Disease with and without dementia and in Dementia with Lewy Bodies. Sci Rep 2018; 8:4717. [PMID: 29549278 PMCID: PMC5856779 DOI: 10.1038/s41598-018-23041-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 03/05/2018] [Indexed: 01/08/2023] Open
Abstract
Mixed pathologies of α-synuclein, β-amyloid and tau are relatively common in Parkinson’s disease (PD) and Dementia with Lewy Bodies (DLB). We therefore wanted to study the retention patterns of 18F-AV-1451 in PD, PD-dementia (PDD), and DLB. To do this 44 healthy controls, 11 non-demented patients with PD, 18 patients with PDD, and six patients with DLB underwent MRI and 18F-AV-1451 PET scanning and cognitive testing. We found that parietal 18F-AV-1451 retention was increased in patients with DLB compared to controls and PD patients, while 18F-AV-1451 uptake was reduced in the substantia nigra in PDD. Increased parietal 18F-AV-1451 PET uptake was associated with impaired performance on verbal fluency tests, and the decreased uptake in the substantia nigra correlated with worse motor function. We found no effect of the monoamine oxidase B inhibitor rasagiline on 18F-AV-1451 binding. In conclusion DLB patients have increased parietal 18F-AV-1451 uptake. Increased parietal tau is associated with executive impairment in patients with synucleinopathies, while decreased uptake in the substantia nigra is associated with parkinsonism. Further, our data indicate that 18F-AV-1451 does not significantly bind to MAO-B in vivo.
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Affiliation(s)
- Ruben Smith
- Department of Neurology, Skåne University Hospital, Lund, Sweden. .,Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.
| | - Michael Schöll
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.,Wallenberg Centre for Molecular and Translational Medicine and the Department of Psychiatry and Neurochemistry, University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Londos
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.,Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Tomas Ohlsson
- Department of Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden. .,Memory Clinic, Skåne University Hospital, Malmö, Sweden.
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Lemoine L, Leuzy A, Chiotis K, Rodriguez-Vieitez E, Nordberg A. Tau positron emission tomography imaging in tauopathies: The added hurdle of off-target binding. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2018; 10:232-236. [PMID: 29780868 PMCID: PMC5956931 DOI: 10.1016/j.dadm.2018.01.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Ligands targeting tau for use with positron emission tomography have rapidly been developed during the past several years, enabling the in vivo study of tau pathology in patients with Alzheimer's disease and related non-Alzheimer's disease tauopathies. Several candidate compounds have been developed, showing good in vitro characteristics with respect to their ability to bind tau deposits; off-target binding, however, has also been observed. In this short commentary, we briefly summarize the available in vivo and in vitro evidence pertaining to their off-target binding and discuss the different approaches that are needed for the future development of tau positron emission tomography tracers.
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Affiliation(s)
- Laetitia Lemoine
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden
- Corresponding author. Tel.: +46 8 524 83 527; Fax: +46 8 585 85470 .
| | - Antoine Leuzy
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden
| | - Konstantinos Chiotis
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden
| | - Elena Rodriguez-Vieitez
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden
- Theme Aging, Karolinska University Hospital, Huddinge, Sweden
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Abstract
Background Positron emission tomography ligands are now available that bind to tau proteins in the brain, providing the exciting opportunity to assess the presence and distribution of tau in vivo in living patients. Methods This manuscript performed a systematic review of studies that have performed tau PET imaging in patients with parkinsonian disorders. Pubmed was searched up to November 2017, and the review included case reports and patient-control studies. Results Most tau-PET studies have utilized the [18F]AV-1451 ligand, with a few using the [11C]PBB3 and [18F]THK-5351 ligands. Elevated cortical tau-PET uptake has been observed in Parkinson's disease dementia and dementia with Lewy bodies, presumed to be related to Alzheimer's disease-related pathology. Mild patterns of tau-PET uptake have been observed in subcortical structures in progressive supranuclear palsy and subcortical structures and motor cortex in corticobasal syndrome, although discrepancy with autoradiographic studies that show lack of binding to 4-repeat tau and "off-target" binding observed in subcortical structures limits interpretation of these findings. Findings in frontotemporal dementia with tau mutations are variable, but elevated signal is most pronounced in mutations with deposition of both 3 and 4-repeat tau. Elevated tau-PET uptake has also been observed in multiple system atrophy, a synucleinopathy. Conclusion The value of the current generation of tau-PET ligands varies across Parkinsonian syndromes depending upon underlying variability in tau pathology and "off-target" binding. More work is needed to understand the biological basis of binding and more specific tau PET ligands are needed to study parkinsonian disorders.
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