Browsing by Subject "Amyloid PET"

Now showing 1 - 5 of 5
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    Amyloid and Tau Pathology are Associated with Cerebral Blood Flow in a Mixed Sample of Nondemented Older Adults with and without Vascular Risk Factors for Alzheimer’s Disease
    (Elsevier, 2023) Swinford, Cecily G.; Risacher, Shannon L.; Vosmeier, Aaron; Deardorff, Rachael; Chumin, Evgeny J.; Dzemidzic, Mario; Wu, Yu-Chien; Gao, Sujuan; McDonald, Brenna C.; Yoder, Karmen K.; Unverzagt, Frederick W.; Wang, Sophia; Farlow, Martin R.; Brosch, Jared R.; Clark, David G.; Apostolova, Liana G.; Sims, Justin; Wang, Danny J.; Saykin, Andrew J.; Radiology and Imaging Sciences, School of Medicine
    Identification of biomarkers for the early stages of Alzheimer's disease (AD) is an imperative step in developing effective treatments. Cerebral blood flow (CBF) is a potential early biomarker for AD; generally, older adults with AD have decreased CBF compared to normally aging peers. CBF deviates as the disease process and symptoms progress. However, further characterization of the relationships between CBF and AD risk factors and pathologies is still needed. We assessed the relationships between CBF quantified by arterial spin-labeled magnetic resonance imaging, hypertension, APOEε4, and tau and amyloid positron emission tomography in 77 older adults: cognitively normal, subjective cognitive decline, and mild cognitive impairment. Tau and amyloid aggregation were related to altered CBF, and some of these relationships were dependent on hypertension or APOEε4 status. Our findings suggest a complex relationship between risk factors, AD pathologies, and CBF that warrants future studies of CBF as a potential early biomarker for AD.
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    Amyloid PET predicts longitudinal functional and cognitive trajectories in a heterogeneous cohort
    (Wiley, 2025) Younes, Kyan; Johns, Emily; Young, Christina B.; Kennedy, Gabriel; Mukherjee, Shubhabrata; Vossler, Hillary A.; Winer, Joseph; Cody, Karly; Henderson, Victor W.; Poston, Kathleen L.; Betthauser, Tobey J.; Bevis, Bill; Brooks, William M.; Burns, Jeffrey M.; Coombes, Stephen A.; DeCarli, Charles; DiFilippo, Frank P.; Duara, Ranjan; Fan, Audrey P.; Gibbons, Laura E.; Golde, Todd; Johnson, Sterling C.; Lepping, Rebecca J.; Leverenz, James; McDougall, Sean; Rogalski, Emily; Sanders, Elizabeth; Pasaye, Joshua; Sridhar, Jaiashre; Saykin, Andrew J.; Sridharan, Anjali; Swerdlow, Russell; Trittschuh, Emily H.; Vaillancourt, David; Vidoni, Eric; Wang, Wei-En; Mez, Jesse; Hohman, Timothy J.; Tosun, Duygu; Biber, Sarah; Kukull, Walter A.; Crane, Paul K.; Mormino, Elizabeth C.; Radiology and Imaging Sciences, School of Medicine
    Introduction: Amyloid positron emission tomography (PET) is increasingly available for diagnosis of Alzheimer`s disease (AD); however, its practical implications in heterogenous cohorts are debated. Methods: Amyloid PET from 890 National Alzheimer`s Coordinating Center participants with up to 10 years post-PET follow up was analyzed. Cox proportional hazards and linear mixed models were used to investigate amyloid burden prediction of etiology and prospective functional status and cognitive decline. Results: Amyloid positivity was associated with progression from unimpaired to mild cognitive impairment and dementia. Amyloid burden in the unimpaired group was associated with lower initial memory levels and faster decline in memory, language, and global cognition. In the Impaired group, amyloid was associated with lower initial levels and faster decline for memory, language, executive function, and global cognition. Discussion: Amyloid burden is an important prognostic marker in a clinically heterogeneous cohort. Future work is needed to establish the proportion of decline driven by AD versus non-AD processes in the context of mixed pathology. Highlights: Our findings highlight the importance of amyloid positron emission tomography (PET) in heterogenous cohorts, including diverse demographics, clinical syndromes, and underlying etiologies. The results also provide evidence that higher amyloid levels were linked to functional progression from unimpaired cognition to mild cognitive impairment (MCI) and from MCI to dementia. In cognitively unimpaired individuals, higher amyloid burden was associated with poorer memory at baseline and subsequent declines in memory, language, and global cognition. Among individuals with cognitive impairment, amyloid burden was associated with worse initial memory, language, executive function, and global cognition, and faster declines over time.
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    Association of Serum Liver Enzymes with Brain Amyloidopathy and Cognitive Performance
    (IOS Press, 2023-12-29) Han, Sang-Won; Lee, Sang-Hwa; Kim, Jong Ho; Lee, Jae-Jun; Park, Young Ho; Kim, SangYun; Nho, Kwangsik; Sohn, Jong-Hee; Radiology and Imaging Sciences, School of Medicine
    Background: Alzheimer's disease (AD) is characterized by amyloid-β (Aβ) plaque accumulation and neurofibrillary tangles in the brain. Emerging evidence has suggested potential interactions between the brain and periphery, particularly the liver, in regulating Aβ homeostasis. Objective: This study aimed to investigate the association of serum liver enzymes with brain amyloidopathy and cognitive performance in patients with complaints of cognitive decline. Methods: A total of 1,036 patients (mean age 74 years, 66.2% female) with subjective cognitive decline, mild cognitive impairment, AD dementia, and other neurodegenerative diseases were included using the Smart Clinical Data Warehouse. Amyloid positron emission tomography (PET) imaging, comprehensive neuropsychological evaluations, and measurements of liver enzymes, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, total bilirubin, and albumin, were assessed. After propensity score matching, logistic and linear regression analyses were used to investigate the associations between liver enzymes, amyloid status, and cognitive performance. Additionally, a machine learning approach was used to assess the classification performance of liver enzymes in predicting amyloid PET positivity. Results: Lower ALT levels and higher AST-to-ALT ratios were significantly associated with amyloid PET positivity and AD diagnosis. The AST-to-ALT ratio was also significantly associated with poor memory function. Machine learning analysis revealed that the classification performance of amyloid status (AUC = 0.642) for age, sex, and apolipoprotein E ɛ4 carrier status significantly improved by 6.2% by integrating the AST-to-ALT ratio. Conclusions: These findings highlight the potential association of liver function on AD and its potential as a diagnostic and therapeutic implications.
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    Predicting conversion of brain β-amyloid positivity in amyloid-negative individuals
    (BMC, 2022-09-12) Park, Chae Jung; Seo, Younghoon; Choe, Yeong Sim; Jang, Hyemin; Lee, Hyejoo; Kim, Jun Pyo; Alzheimer’s Disease Neuroimaging Initiative; Radiology and Imaging Sciences, School of Medicine
    Background: Cortical deposition of β-amyloid (Aβ) plaque is one of the main hallmarks of Alzheimer's disease (AD). While Aβ positivity has been the main concern so far, predicting whether Aβ (-) individuals will convert to Aβ (+) has become crucial in clinical and research aspects. In this study, we aimed to develop a classifier that predicts the conversion from Aβ (-) to Aβ (+) using artificial intelligence. Methods: Data were obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort regarding patients who were initially Aβ (-). We developed an artificial neural network-based classifier with baseline age, gender, APOE ε4 genotype, and global and regional standardized uptake value ratios (SUVRs) from positron emission tomography. Ten times repeated 10-fold cross-validation was performed for model measurement, and the feature importance was assessed. To validate the prediction model, we recruited subjects at the Samsung Medical Center (SMC). Results: A total of 229 participants (53 converters) from the ADNI dataset and a total of 40 subjects (10 converters) from the SMC dataset were included. The average area under the receiver operating characteristic values of three developed models are as follows: Model 1 (age, gender, APOE ε4) of 0.674, Model 2 (age, gender, APOE ε4, global SUVR) of 0.814, and Model 3 (age, gender, APOE ε4, global and regional SUVR) of 0.841. External validation result showed an AUROC of 0.900. Conclusion: We developed prediction models regarding Aβ positivity conversion. With the growing recognition of the need for earlier intervention in AD, the results of this study are expected to contribute to the screening of early treatment candidates.
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    Sex and APOE ε4 carrier effects on atrophy, amyloid PET, and tau PET burden in early-onset Alzheimer's disease
    (Wiley, 2023) Nemes, Sára; Logan, Paige E.; Manchella, Mohit K.; Mundada, Nidhi S.; La Joie, Renaud; Polsinelli, Angelina J.; Hammers, Dustin B.; Koeppe, Robert A.; Foroud, Tatiana M.; Nudelman, Kelly N.; Eloyan, Ani; Iaccarino, Leonardo; Dorsant-Ardón, Valérie; Taurone, Alexander; Thangarajah, Maryanne; Dage, Jeffery L.; Aisen, Paul; Grinberg, Lea T.; Jack, Clifford R., Jr.; Kramer, Joel; Kukull, Walter A.; Murray, Melissa E.; Rumbaugh, Malia; Soleimani-Meigooni, David N.; Toga, Arthur; Touroutoglou, Alexandra; Vemuri, Prashanthi; Atri, Alireza; Day, Gregory S.; Duara, Ranjan; Graff-Radford, Neill R.; Honig, Lawrence S.; Jones, David T.; Masdeu, Joseph; Mendez, Mario F.; Musiek, Erik; Onyike, Chiadi U.; Riddle, Meghan; Rogalski, Emily; Salloway, Stephen; Sha, Sharon J.; Turner, Raymond S.; Wingo, Thomas S.; Womack, Kyle B.; Wolk, David A.; Rabinovici, Gil D.; Carrillo, Maria C.; Dickerson, Bradford C.; Apostolova, Liana G.; LEADS Consortium; Neurology, School of Medicine
    Introduction: We used sex and apolipoprotein E ε4 (APOE ε4) carrier status as predictors of pathologic burden in early-onset Alzheimer's disease (EOAD). Methods: We included baseline data from 77 cognitively normal (CN), 230 EOAD, and 70 EO non-Alzheimer's disease (EOnonAD) participants from the Longitudinal Early-Onset Alzheimer's Disease Study (LEADS). We stratified each diagnostic group by males and females, then further subdivided each sex by APOE ε4 carrier status and compared imaging biomarkers in each stratification. Voxel-wise multiple linear regressions yielded statistical brain maps of gray matter density, amyloid, and tau PET burden. Results: EOAD females had greater amyloid and tau PET burdens than males. EOAD female APOE ε4 non-carriers had greater amyloid PET burdens and greater gray matter atrophy than female ε4 carriers. EOnonAD female ε4 non-carriers also had greater gray matter atrophy than female ε4 carriers. Discussion: The effects of sex and APOE ε4 must be considered when studying these populations. Highlights: Novel analysis examining the effects of biological sex and apolipoprotein E ε4 (APOE ε4) carrier status on neuroimaging biomarkers among early-onset Alzheimer's disease (EOAD), early-onset non-AD (EOnonAD), and cognitively normal (CN) participants. Female sex is associated with greater pathology burden in the EOAD cohort compared to male sex. The effect of APOE ε4 carrier status on pathology burden was the most impactful in females across all cohorts.