scholarly journals Tau PET: the next frontier in molecular imaging of dementia

2016 ◽  
Vol 28 (9) ◽  
pp. 1403-1406 ◽  
Author(s):  
Chenjie Xia ◽  
Bradford C. Dickerson
Keyword(s):  
Molecular Imaging ◽  
Amyloid Β ◽  
Amyloid Pet ◽  
Paired Helical Filament ◽  
Prodromal Ad ◽  
Dementia Research ◽  
Tau Pet ◽  
Potential Impact ◽  
First Time ◽  
Amyloid Pet Imaging

We have arrived at an exciting juncture in dementia research: the second major pathological hallmark of Alzheimer's disease (AD)–tau–can now be seen for the first time in the living human brain. The major proteinopathies in AD include amyloid-β plaques and neurofibrillary tangles (NFTs) made of hyperphosphorylated paired helical filament (PHF) tau. Since its advent more than a decade ago, amyloid PET imaging has revolutionized the field of dementia research, enabling more confident diagnosis of the likely pathology in patients with a variety of clinical dementia syndromes, paving the way for the identification of people with preclinical or prodromal AD pathology, and serving as a minimally invasive molecular readout in clinical trials of putative disease-modifying interventions. Now that we are on the brink of a second revolution in molecular imaging in dementia, it is worth considering the likely potential impact of this development on the field.

scholarly journals Topographic Distribution of Amyloid-β, Tau, and Atrophy in Patients With Behavioral/Dysexecutive Alzheimer Disease

Neurology ◽  
2020 ◽  
Vol 96 (1) ◽  
pp. e81-e92
Author(s):  
Joseph Therriault ◽  
Tharick A. Pascoal ◽  
Melissa Savard ◽  
Andrea L. Benedet ◽  
Mira Chamoun ◽  
...  
Keyword(s):  
Alzheimer Disease ◽  
Clinical Symptoms ◽  
Characteristic Curve ◽  
Tertiary Care ◽  
Amyloid Β ◽  
Executive Dysfunction ◽  
Anterior Cingulate ◽  
Amyloid Pet ◽  
Clinical Criteria ◽  
Tau Pet

ObjectiveTo determine the associations between amyloid-PET, tau-PET, and atrophy with the behavioral/dysexecutive presentation of Alzheimer disease (AD), how these differ from amnestic AD, and how they correlate to clinical symptoms.MethodsWe assessed 15 patients with behavioral/dysexecutive AD recruited from a tertiary care memory clinic, all of whom had biologically defined AD. They were compared with 25 patients with disease severity– and age-matched amnestic AD and a group of 131 cognitively unimpaired (CU) elderly individuals. All participants were evaluated with amyloid-PET with [18F]AZD4694, tau-PET with [18F]MK6240, MRI, and neuropsychological testing.ResultsVoxelwise contrasts identified patterns of frontal cortical tau aggregation in behavioral/dysexecutive AD, with peaks in medial prefrontal, anterior cingulate, and frontal insular cortices in contrast to amnestic AD. No differences were observed in the distribution of amyloid-PET or atrophy as determined by voxel-based morphometry. Voxelwise area under the receiver operating characteristic curve analyses revealed that tau-PET uptake in the medial prefrontal, anterior cingulate, and frontal insular cortices were best able to differentiate between behavioral/dysexecutive and amnestic AD (area under the curve 0.87). Voxelwise regressions demonstrated relationships between frontal cortical tau load and degree of executive dysfunction.ConclusionsOur results provide evidence of frontal cortical involvement of tau pathology in behavioral/dysexecutive AD and highlight the need for consensus clinical criteria in this syndrome.

IC-P-156: Baseline amyloid PET imaging, longitudinal amyloid accumulation, and Tau PET imaging in preclinical Alzheimer's disease

2015 ◽  
Vol 11 (7S_Part_2) ◽  
pp. P105-P105
Author(s):  
Aaron P. Schultz ◽  
Elizabeth C. Mormino ◽  
Jasmeer P. Chhatwal ◽  
Molly LaPoint ◽  
Alex S. Dagley ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Pet Imaging ◽  
Amyloid Pet ◽  
Preclinical Alzheimer’S Disease ◽  
Amyloid Accumulation ◽  
Tau Pet ◽  
Tau Pet Imaging ◽  
Amyloid Pet Imaging

scholarly journals Decreased salivary lactoferrin levels are specific to Alzheimer’s disease

2020 ◽  
Author(s):  
Marta González-Sánchez ◽  
Fernando Bartolome ◽  
Desiree Antequera ◽  
Veronica Puertas-Martín ◽  
Pilar González ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Diagnostic Performance ◽  
Group Versus ◽  
Amyloid Β ◽  
University Hospital ◽  
Control Group ◽  
Amyloid Pet ◽  
Prodromal Ad ◽  
Study Participants

Abstract Background Efforts focused on developing new less invasive biomarkers for early Alzheimer’s disease (AD) diagnosis are substantial. Evidences of infectious pathogens in AD brains may suggest a deteriorated innate immune system in AD pathophysiology. We previously demonstrated reduced salivary levels of Lf in AD patients, one of the major antimicrobial peptides. Methods To assess the clinical utility of salivary Lf for AD diagnosis, we examine the relationship between salivary Lf and cerebral amyloid-β (Aβ) load in two different cross-sectional cohorts including patients with different neurodegenerative disorders. Study participants for cohort 1 (n = 116) were enrolled from the 12 de Octubre University Hospital Neurology Service in Madrid (Spain) and Pablo de Olavide University in Sevilla (Spain). Study participants for cohort 2 (n = 142) were enrolled as part of the Atherobrain - Heart to Head (H2H) project. Participants underwent neurological and neuropsychological examination, saliva sampling, and amyloid-Positron-Emission Tomography (PET) neuroimaging. Results The diagnostic performance of salivary Lf in the cohort 1 had an area under the curve [AUC] of 0.95 (0.911-0.992) for the differentiation of the prodromal AD/AD group positive for amyloid-PET (PET + ) versus healthy group, and 0.97 (0.924-1) versus the frontotemporal dementia (FTD) group. In the cohort 2, salivary Lf had also an excellent diagnostic performance in the health control group versus prodromal AD comparison: AUC 0.93 (95% CI 0.876-0.989). Salivary Lf detected prodromal AD and AD dementia distinguishing them from other dementias as FTD with over 87% sensitivity and 91% specificity. Conclusion Therefore, salivary Lf seems to have a very good diagnostic performance to detect AD. Our findings support the possible utility of salivary Lf as a new non-invasive and cost-effective AD biomarker.

Elevated Tau PET Signal Depends on Abnormal Amyloid Levels and Correlates with Cognitive Impairment in Elderly Persons without Dementia

2020 ◽  
Vol 78 (1) ◽  
pp. 395-404 ◽  
Author(s):  
Rui-Qi Zhang ◽  
Shi-Dong Chen ◽  
Xue-Ning Shen ◽  
Yu-Xiang Yang ◽  
Jia-Ying Lu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Executive Function ◽  
Amyloid Β ◽  
Amyloid Pet ◽  
Elderly Persons ◽  
Cross Sectional ◽  
Memory Decline ◽  
Tau Pet

Background: The recent developed PET ligands for amyloid-β (Aβ) and tau allow these two neuropathological hallmarks of Alzheimer’s disease (AD) to be mapped and quantified in vivo and to be examined in relation to cognition. Objective: To assess the associations among Aβ, tau, and cognition in non-demented subjects. Methods: Three hundred eighty-nine elderly participants without dementia from the Alzheimer’s Disease Neuroimaging Initiative underwent tau and amyloid PET scans. Cross-sectional comparisons and longitudinal analyses were used to evaluate the relationship between Aβ and tau accumulation. The correlations between biomarkers of both pathologies and performance in memory and executive function were measured. Results: Increased amyloid-PET retention was associated with greater tau-PET retention in widespread cortices. We observed a significant tau increase in the temporal composite regions of interest over 24 months in Aβ+ but not Aβ– subjects. Finally, tau-PET retention but not amyloid-PET retention significantly explained the variance in memory and executive function. Higher level of tau was associated with greater longitudinal memory decline. Conclusion: These findings suggested PET-detectable Aβ plaque pathology may be a necessary antecedent for tau-PET signal elevation. Greater tau-PET retention may demonstrate poorer cognition and predict prospective memory decline in non-demented subjects.

PET Amyloid and Tau Status Are Differently Affected by Patient Features

2020 ◽  
Vol 78 (3) ◽  
pp. 1129-1136
Author(s):  
Meng-Shan Tan ◽  
Yu-Xiang Yang ◽  
Hui-Fu Wang ◽  
Wei Xu ◽  
Chen-Chen Tan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Β ◽  
Amyloid Pet ◽  
Tau Pathology ◽  
Clinical Genetic ◽  
Multivariable Logistic Regression Model ◽  
Tau Pet ◽  
Pet Amyloid

Background: Amyloid-β (Aβ) plaques and tau neurofibrillary tangles are two neuropathological hallmarks of Alzheimer’s disease (AD), which both can be visualized in vivo using PET radiotracers, opening new opportunities to study disease mechanisms. Objective: Our study investigated 11 non-PET factors in 5 categories (including demographic, clinical, genetic, MRI, and cerebrospinal fluid (CSF) features) possibly affecting PET amyloid and tau status to explore the relationships between amyloid and tau pathology, and whether these features had a different association with amyloid and tau status. Methods: We included 372 nondemented elderly from the Alzheimer’s Disease Neuroimaging Initiative cohort. All underwent PET amyloid and tau analysis simultaneously, and were grouped into amyloid/tau quadrants based on previously established abnormality cut points. We examined the associations of above selected features with PET amyloid and tau status using a multivariable logistic regression model, then explored whether there was an obvious correlation between the significant features and PET amyloid or tau levels. Results: Our results demonstrated that PET amyloid and tau status were differently affected by patient features, and CSF biomarker features provided most significant values associating PET findings. CSF Aβ42/40 was the most important factor affecting amyloid PET status, and negatively correlated with amyloid PET levels. CSF pTau could significantly influence both amyloid and tau PET status. Besides CSF pTau and Aβ42, APOE ɛ4 allele status and Mini-Mental State Examination scores also could influence tau PET status, and significantly correlated with tau PET levels. Conclusion: Our results support that tau pathology possibly affected by Aβ-independent factors, implicating the importance of tau pathology in AD pathogenesis.

O1-06-05: Baseline amyloid PET imaging, longitudinal amyloid accumulation, and Tau PET imaging in preclinical Alzheimer's disease

2015 ◽  
Vol 11 (7S_Part_3) ◽  
pp. P139-P139
Author(s):  
Aaron P. Schultz ◽  
Elizabeth C. Mormino ◽  
Jasmeer P. Chhatwal ◽  
Molly LaPoint ◽  
Alex S. Dagley ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Pet Imaging ◽  
Amyloid Pet ◽  
Preclinical Alzheimer’S Disease ◽  
Amyloid Accumulation ◽  
Tau Pet ◽  
Tau Pet Imaging ◽  
Amyloid Pet Imaging

scholarly journals Frequency of biologically-defined AD in relation to age, sex, APOEε4 and cognitive impairment

Neurology ◽  
2020 ◽  
pp. 10.1212/WNL.0000000000011416
Author(s):  
Joseph Therriault ◽  
Tharick A. Pascoal ◽  
Andrea L. Benedet ◽  
Cecile Tissot ◽  
Melissa Savard ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Clinical Diagnosis ◽  
Predictive Value ◽  
Tertiary Care ◽  
Amyloid Β ◽  
Elderly Subjects ◽  
Complete Agreement ◽  
Amyloid Pet ◽  
Memory Clinics ◽  
Tau Pet

Objective:To assess the frequency of biologically-defined Alzheimer’s disease (AD) in relation to age, sex, APOEε4, and clinical diagnosis in a prospective cohort study evaluated with amyloid-PET and tau-PET.Methods:We assessed cognitively unimpaired (CU) elderly (n=166), amnestic MCI (n=77) and probable AD dementia (n=62) subjects who underwent evaluation by dementia specialists and neuropsychologists in addition to amyloid-PET with [18F]AZD4694 and tau-PET with [18F]MK6240. Individuals were grouped according to their AD biomarker profile. Positive predictive value for biologically-defined AD was assessed in relation to clinical diagnosis. Frequency of AD biomarker profiles were assessed using logistic regressions with odds ratios and 95% CIs.Results:The clinical diagnosis of probable AD dementia demonstrated good agreement with biologically-defined AD (positive predictive value: 85.2%). 7.88% of CU elderly subjects were positive for both amyloid-PET and tau-PET. Frequency of biologically-defined AD increased with age (OR: 1.14; p<0.0001) and frequency of APOEε4 allele carriers (Single ε4: OR: 3.82; p<0.0001; Double ε4: OR: 17.55, p<0.0001).Discussion:While we observed strong, but not complete, agreement between clinically-defined “probable AD” dementia and biomarker positivity for both amyloid-β and tau, we also observed that biologically-defined AD was not rare in CU elderly. Abnormal tau-PET was almost exclusively observed in individuals with abnormal amyloid-PET. Our results highlight that even in tertiary care memory clinics, detailed evaluation by dementia specialists systematically underestimates the frequency of biologically-defined AD and related entities.Classification of evidence:This study provides Class I evidence that biologically-defined AD (abnormal amyloid PET and tau PET) was observed in 85.2% of people with clinically defined AD and 7.88% of cognitively unimpaired elderly.

scholarly journals The bivariate distribution of amyloid-β and tau: relationship with established neurocognitive clinical syndromes

Brain ◽  
2019 ◽  
Vol 142 (10) ◽  
pp. 3230-3242 ◽  
Author(s):  
Clifford R Jack ◽  
Heather J Wiste ◽  
Hugo Botha ◽  
Stephen D Weigand ◽  
Terry M Therneau ◽  
...  
Keyword(s):  
Amyloid Β ◽  
Bivariate Distribution ◽  
Amyloid Pet ◽  
Clinical Syndromes ◽  
Β Amyloid ◽  
Tau Pet ◽  
Normal Cognition

See Gordon and Tijms (doi:10.1093/brain/awz278) for a scientific commentary on this article. Jack et al. examine relationships between the bivariate distribution of β-amyloid and tau on PET and established neurocognitive clinical syndromes. Amyloidosis appears to be required for high levels of 3R/4R tau deposition. Whereas abnormal amyloid PET is compatible with normal cognition, highly abnormal tau PET is not.

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