scholarly journals Imaging biomarkers for amyloid: a new generation of probes and what lies ahead

2014 ◽  
Vol 26 (5) ◽  
pp. 703-707 ◽  
Author(s):  
Antoine Leuzy ◽  
Eduardo Rigon Zimmer ◽  
Venkat Bhat ◽  
Pedro Rosa-Neto ◽  
Serge Gauthier
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Work Group ◽  
Imaging Biomarkers ◽  
Amyloid A ◽  
Positron Emission ◽  
Communicative Disorders ◽  
Physiologic Parameters ◽  
New Generation

Since the original 1984 criteria for Alzheimer's disease (AD), put forth by a work group jointly established by the National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) and the Alzheimer's Disease and Related Disorders Association (ADRDA) (McKhann et al., 1984), important advances have occurred in our ability to detect AD pathophysiology, with the incorporation of biomarkers – defined as anatomic, biochemical, or physiologic parameters that provide in vivo evidence of AD neuropathology (Cummings, 2011) – that can improve the certainty of AD diagnosis. Use of imaging biomarkers such as positron emission tomography (PET) with amyloid ligands, particularly in asymptomatic and pre-dementia stages of AD, however, has been the subject of debate (Dubois et al., 2013), with arguments both for and against the biomarker driven diagnosis of AD.

scholarly journals PET Imaging of Neuroinflammation in Alzheimer’s Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Rong Zhou ◽  
Bin Ji ◽  
Yanyan Kong ◽  
Limei Qin ◽  
Wuwei Ren ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Time Course ◽  
Rapid Development ◽  
Translocator Protein ◽  
Positron Emission ◽  
Protein Tracers ◽  
Improved Performance ◽  
New Generation

Neuroinflammation play an important role in Alzheimer’s disease pathogenesis. Advances in molecular imaging using positron emission tomography have provided insights into the time course of neuroinflammation and its relation with Alzheimer’s disease central pathologies in patients and in animal disease models. Recent single-cell sequencing and transcriptomics indicate dynamic disease-associated microglia and astrocyte profiles in Alzheimer’s disease. Mitochondrial 18-kDa translocator protein is the most widely investigated target for neuroinflammation imaging. New generation of translocator protein tracers with improved performance have been developed and evaluated along with tau and amyloid imaging for assessing the disease progression in Alzheimer’s disease continuum. Given that translocator protein is not exclusively expressed in glia, alternative targets are under rapid development, such as monoamine oxidase B, matrix metalloproteinases, colony-stimulating factor 1 receptor, imidazoline-2 binding sites, cyclooxygenase, cannabinoid-2 receptor, purinergic P2X7 receptor, P2Y12 receptor, the fractalkine receptor, triggering receptor expressed on myeloid cells 2, and receptor for advanced glycation end products. Promising targets should demonstrate a higher specificity for cellular locations with exclusive expression in microglia or astrocyte and activation status (pro- or anti-inflammatory) with highly specific ligand to enable in vivo brain imaging. In this review, we summarised recent advances in the development of neuroinflammation imaging tracers and provided an outlook for promising targets in the future.

scholarly journals Imaging and Molecular Mechanisms of Alzheimer’s Disease: A Review

2018 ◽  
Vol 19 (12) ◽  
pp. 3702 ◽  
Author(s):  
Grazia Femminella ◽  
Tony Thayanandan ◽  
Valeria Calsolaro ◽  
Klara Komici ◽  
Giuseppe Rengo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Multimodal Imaging ◽  
Molecular Mechanisms ◽  
Imaging Techniques ◽  
Structural Mri ◽  
Imaging Biomarkers ◽  
Significant Burden ◽  
Made In

Alzheimer’s disease is the most common form of dementia and is a significant burden for affected patients, carers, and health systems. Great advances have been made in understanding its pathophysiology, to a point that we are moving from a purely clinical diagnosis to a biological one based on the use of biomarkers. Among those, imaging biomarkers are invaluable in Alzheimer’s, as they provide an in vivo window to the pathological processes occurring in Alzheimer’s brain. While some imaging techniques are still under evaluation in the research setting, some have reached widespread clinical use. In this review, we provide an overview of the most commonly used imaging biomarkers in Alzheimer’s disease, from molecular PET imaging to structural MRI, emphasising the concept that multimodal imaging would likely prove to be the optimal tool in the future of Alzheimer’s research and clinical practice.

Structural, Functional, and Molecular Neuroimaging Biomarkers for Alzheimer’s Disease

2013 ◽  
pp. 821-825
Author(s):  
James B. Brewer ◽  
Jorge Sepulcre ◽  
Keith A. Johnson
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Cognitive Impairment ◽  
Neurodegenerative Disorders ◽  
Brain Dysfunction ◽  
Imaging Biomarkers ◽  
Neurocognitive Evaluation ◽  
Neuroimaging Biomarkers

Advances in quantitative structural, functional, and molecular neuroimaging have provided new tools for objective, in vivo, assessment of critical aspects of Alzheimer’s disease and other neurodegenerative disorders. Measures of brain atrophy or brain dysfunction, coupled with measures of disease-linked pathology, might complement the history, physical and neurocognitive evaluation of patients and thereby improve predictive prognosis, especially at early stages of cognitive impairment where neurodegenerative etiology is less certain. Such imaging biomarkers are currently used in nearly all clinical trials of therapeutic agents for Alzheimer’s disease and are increasingly incorporated into clinical practice. In this chapter, imaging biomarkers are introduced and discussed to familiarize the reader with their potential research and clinical uses.

Associations of Neprilysin Activity in CSF with Biomarkers for Alzheimer’s Disease

2019 ◽  
Vol 19 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Timo Grimmer ◽  
Oliver Goldhardt ◽  
Igor Yakushev ◽  
Marion Ortner ◽  
Christian Sorg ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Fdg Pet ◽  
Amyloid Β ◽  
Neuronal Injury ◽  
Pittsburgh Compound B ◽  
Positron Emission ◽  
Amyloid Load ◽  
Alzheimer’S Pathology

Background: Neprilysin (NEP) cleaves amyloid-β 1–42 (Aβ42) in the brain. Hence, we aimed to elucidate the effect of NEP on Aβ42 in cerebrospinal fluid (CSF) and on in vivo brain amyloid load using amyloid positron emission tomography (PET) with [11C]PiB (Pittsburgh compound B). In addition, associations with the biomarkers for neuronal injury, CSF-tau and FDG-PET, were investigated. Methods: Associations were calculated using global and voxel-based (SPM8) linear regression analyses in the same cohort of 23 highly characterized Alzheimer’s disease patients. Results: CSF-NEP was significantly inversely associated with CSF-Aβ42 and positively with the extent of neuronal injury as measured by CSF-tau and FDG-PET. Conclusions: Our results on CSF-NEP are compatible with the assumption that local degradation, amongst other mechanisms of amyloid clearance, plays a role in the development of Alzheimer’s pathology. In addition, CSF-NEP is associated with the extent and the rate of neurodegeneration.

scholarly journals In vivo imaging of synaptic loss in Alzheimer’s disease with [18F]UCB-H positron emission tomography

2019 ◽  
Vol 47 (2) ◽  
pp. 390-402 ◽  
Author(s):  
Christine Bastin ◽  
Mohamed Ali Bahri ◽  
François Meyer ◽  
Marine Manard ◽  
Emma Delhaye ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Positron Emission Tomography ◽  
In Vivo Imaging ◽  
Emission Tomography ◽  
Synaptic Loss ◽  
Positron Emission

IC-P-024: A novel positron emission tomography contrast agent targeting cathepsin d shows preferential in vivo retention in an Alzheimer's disease mouse model

2015 ◽  
Vol 11 (7S_Part_1) ◽  
pp. P26-P27
Author(s):  
Jonatan A. Snir ◽  
Mojmir Suchy ◽  
Geron A. Bindseil ◽  
Blaine A. Chronik ◽  
Robert H.E. Hudson ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Positron Emission Tomography ◽  
Mouse Model ◽  
Contrast Agent ◽  
Cathepsin D ◽  
Emission Tomography ◽  
Positron Emission

O1-02-05: A novel positron emission tomography contrast agent targeting cathepsin d shows preferential in vivo retention in an Alzheimer's disease mouse model

2015 ◽  
Vol 11 (7S_Part_3) ◽  
pp. P128-P128
Author(s):  
Jonatan A. Snir ◽  
Mojmir Suchy ◽  
Geron A. Bindseil ◽  
Blaine A. Chronik ◽  
Robert H.E. Hudson ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Positron Emission Tomography ◽  
Mouse Model ◽  
Contrast Agent ◽  
Cathepsin D ◽  
Emission Tomography ◽  
Positron Emission

scholarly journals Prospective longitudinal atrophy in Alzheimer’s disease correlates with the intensity and topography of baseline tau-PET

2020 ◽  
Vol 12 (524) ◽  
pp. eaau5732 ◽  
Author(s):  
Renaud La Joie ◽  
Adrienne V. Visani ◽  
Suzanne L. Baker ◽  
Jesse A. Brown ◽  
Viktoriya Bourakova ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Pet ◽  
Specific Distribution ◽  
Positron Emission ◽  
Pet Radiotracers ◽  
Β Amyloid ◽  
Tau Pet ◽  
Prospective Longitudinal

β-Amyloid plaques and tau-containing neurofibrillary tangles are the two neuropathological hallmarks of Alzheimer’s disease (AD) and are thought to play crucial roles in a neurodegenerative cascade leading to dementia. Both lesions can now be visualized in vivo using positron emission tomography (PET) radiotracers, opening new opportunities to study disease mechanisms and improve patients’ diagnostic and prognostic evaluation. In a group of 32 patients at early symptomatic AD stages, we tested whether β-amyloid and tau-PET could predict subsequent brain atrophy measured using longitudinal magnetic resonance imaging acquired at the time of PET and 15 months later. Quantitative analyses showed that the global intensity of tau-PET, but not β-amyloid–PET, signal predicted the rate of subsequent atrophy, independent of baseline cortical thickness. Additional investigations demonstrated that the specific distribution of tau-PET signal was a strong indicator of the topography of future atrophy at the single patient level and that the relationship between baseline tau-PET and subsequent atrophy was particularly strong in younger patients. These data support disease models in which tau pathology is a major driver of local neurodegeneration and highlight the relevance of tau-PET as a precision medicine tool to help predict individual patient’s progression and design future clinical trials.

scholarly journals Combined Study of Cerebral Glucose Metabolism and [11C]Methionine Accumulation in Probable Alzheimer's Disease Using Positron Emission Tomography

1996 ◽  
Vol 16 (3) ◽  
pp. 399-408 ◽  
Author(s):  
E. Salmon ◽  
M. C. Gregoire ◽  
G. Delfiore ◽  
C. Lemaire ◽  
C. Degueldre ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Positron Emission Tomography ◽  
Glucose Metabolism ◽  
Clinical Symptoms ◽  
Synaptic Activity ◽  
Emission Tomography ◽  
Tissue Loss ◽  
Positron Emission

There is a characteristic decrease in glucose metabolism in associative frontal and temporo-parietal cortices of patients suffering from Alzheimer's disease (AD). The decrease in metabolism might result from local neuronal loss or from a decrease of synaptic activity. We measured in vivo [11C]methionine accumulation into proteins with positron emission tomography (PET) to assess cortical tissue loss in AD. Both global regional activity and compartmental analysis were used to express [11C]methionine accumulation into brain tissue. Glucose metabolism was measured with [18F]fluorodeoxyglucose and autoradiographic method. Combined studies were performed in 10 patients with probable AD, compared to age-matched healthy volunteers. There was a significant 45% decrease of temporo-parietal glucose metabolism in patients with AD, and frontal metabolism was lowered in most patients. Temporo-parietal metabolism correlated to dementia severity. [11C]methionine incorporation into temporo-parietal and frontal cortices was not significantly decreased in AD. There was no correlation with clinical symptoms. Data suggest that regional tissue loss, assessed by the decrease of [11C]methionine accumulation, is not sufficient to explain cortical glucose hypometabolism, which reflects, rather, reduced synaptic connectivity.

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