Browsing by Author "Vemuri, Prashanthi"

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    Amyloid and tau-PET in early-onset AD: Baseline data from the Longitudinal Early-onset Alzheimer's Disease Study (LEADS)
    (Wiley, 2023) Cho, Hanna; Mundada, Nidhi S.; Apostolova, Liana G.; Carrillo, Maria C.; Shankar, Ranjani; Amuiri, Alinda N.; Zeltzer, Ehud; Windon, Charles C.; Soleimani-Meigooni, David N.; Tanner, Jeremy A.; Heath, Courtney Lawhn; Lesman-Segev, Orit H.; Aisen, Paul; Eloyan, Ani; Lee, Hye Sun; Hammers, Dustin B.; Kirby, Kala; Dage, Jeffrey L.; Fagan, Anne; Foroud, Tatiana; Grinberg, Lea T.; Jack, Clifford R.; Kramer, Joel; Kukull, Walter A.; Murray, Melissa E.; Nudelman, Kelly; Toga, Arthur; Vemuri, Prashanthi; Atri, Alireza; Day, Gregory S.; Duara, Ranjan; Graff-Radford, Neill R.; Honig, Lawrence S.; Jones, David T.; Masdeu, Joseph; Mendez, Mario; Musiek, Erik; Onyike, Chiadi U.; Riddle, Meghan; Rogalski, Emily J.; Salloway, Stephen; Sha, Sharon; Turner, Raymond Scott; Wingo, Thomas S.; Wolk, David A.; Koeppe, Robert; Iaccarino, Leonardo; Dickerson, Bradford C.; La Joie, Renaud; Rabinovici, Gil D.; LEADS Consortium; Neurology, School of Medicine
    Introduction: We aimed to describe baseline amyloid-beta (Aβ) and tau-positron emission tomograrphy (PET) from Longitudinal Early-onset Alzheimer's Disease Study (LEADS), a prospective multi-site observational study of sporadic early-onset Alzheimer's disease (EOAD). Methods: We analyzed baseline [18F]Florbetaben (Aβ) and [18F]Flortaucipir (tau)-PET from cognitively impaired participants with a clinical diagnosis of mild cognitive impairment (MCI) or AD dementia aged < 65 years. Florbetaben scans were used to distinguish cognitively impaired participants with EOAD (Aβ+) from EOnonAD (Aβ-) based on the combination of visual read by expert reader and image quantification. Results: 243/321 (75.7%) of participants were assigned to the EOAD group based on amyloid-PET; 231 (95.1%) of them were tau-PET positive (A+T+). Tau-PET signal was elevated across cortical regions with a parietal-predominant pattern, and higher burden was observed in younger and female EOAD participants. Discussion: LEADS data emphasizes the importance of biomarkers to enhance diagnostic accuracy in EOAD. The advanced tau-PET binding at baseline might have implications for therapeutic strategies in patients with EOAD. Highlights: 72% of patients with clinical EOAD were positive on both amyloid- and tau-PET. Amyloid-positive patients with EOAD had high tau-PET signal across cortical regions. In EOAD, tau-PET mediated the relationship between amyloid-PET and MMSE. Among EOAD patients, younger onset and female sex were associated with higher tau-PET.
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    Amyloid‐PET in patients with a clinical diagnosis of sporadic early‐ versus late‐onset AD: comparison of the LEADS and ADNI cohorts
    (Wiley, 2025-01-09) Lagarde, Julien; Maiti, Piyush; Schonhaut, Daniel R.; Zhang, Jiaxiuxiu; Soleimani-meigooni, David N.; Zeltzer, Ehud; Windon, Charles; Raya, Maison Abu; Vrillon, Agathe; Hammers, Dustin B.; Dage, Jeffrey L.; Nudelman, Kelly N.; Eloyan, Ani; Koeppe, Robert A.; Landau, Susan M.; Carrillo, Maria C.; Touroutoglou, Alexandra; Vemuri, Prashanthi; Dickerson, Bradford C.; Apostolova, Liana G.; Rabinovici, Gil D.; La Joie, Renaud; LEADS Consortium, Alzheimer’s Disease Neuroimaging Initiative; Neurology, School of Medicine
    Background: Large‐scale studies comparing sporadic early‐onset AD (EOAD, age<65) and late‐onset AD (LOAD, age≥65) are lacking. We compared amyloid‐PET outcomes (positivity rate and amyloid burden) between patients clinically diagnosed with sporadic EOAD vs LOAD, leveraging data from the Longitudinal Early‐Onset AD Study (LEADS) and the Alzheimer’s Disease Neuroimaging Initiative 3 (ADNI3). Method: 731 patients meeting the 2011 NIA‐AA criteria for AD dementia or MCI were included (505 early‐onset from LEADS, 226 late‐onset from ADNI3, Table 1). All participants underwent amyloid‐PET with [18F]Florbetaben or [18F]Florbetapir. Amyloid positivity was centrally determined by a process involving a visual read by a trained expert and PET‐only quantification; in case of a discrepancy, a read from an independent physician acted as a tiebreaker. Logistic regressions in each cohort examined relations between amyloid positivity and age, sex, MMSE and APOE4 genotype. Amyloid burden was independently quantified in Centiloids using an MRI‐based pipeline. Mean Centiloids in LEADS and ADNI were compared with two‐way ANOVA, for visually positive and visually negative scans. Result: Amyloid positivity rate was higher in LEADS (76%) than ADNI (64%, p<0.001, Figure 1A). Lower MMSE and APOE4 genotype increased odds of amyloid positivity in both cohorts, although the APOE4 effect was stronger in ADNI than LEADS (OR=10.1 versus 2.4, p=0.007, Table 2). Amyloid positivity was more common in females across cohorts, but this effect was only statistically significant in LEADS (Table 2). Centiloids were bimodally distributed in both cohorts, although the separation between positive and negative scans was more prominent in LEADS (Figure 1B). Visually positive scans had significantly higher Centiloids in LEADS than in ADNI, whereas no cohort difference was observed for visually negative scans (Figure 1C). Sensitivity analyses showed that this effect was driven by patients with MCI (CDR≤0.5; Figure 1D‐E). Conclusion: The lower amyloid positivity rate in ADNI might be due to AD‐mimicking pathologies being more common at an older age. The higher amyloid burden in early‐onset, amyloid‐positive patients could reflect younger patients being diagnosed later in the disease course compared to typical, late‐onset patients. Alternatively, younger patients might tolerate higher neuropathology burden due to higher brain reserve or fewer co‐pathologies.
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    Baseline neuropsychiatric symptoms and psychotropic medication use midway through data collection of the Longitudinal Early-Onset Alzheimer's Disease Study (LEADS) cohort
    (Wiley, 2023) Polsinelli, Angelina J.; Wonderlin, Ryan J.; Hammers, Dustin B.; Pena Garcia, Alex; Eloyan, Anii; Taurone, Alexander; Thangarajah, Maryanne; Beckett, Laurel; Gao, Sujuan; Wang, Sophia; Kirby, Kala; Logan, Paige E.; Aisen, Paul; Dage, Jeffrey L.; Foroud, Tatiana; Griffin, Percy; Iaccarino, Leonardo; Kramer, Joel H.; Koeppe, Robert; Kukull, Walter A.; La Joie, Renaud; Mundada, Nidhi S.; Murray, Melissa E.; Nudelman, Kelly; Soleimani-Meigooni, David N.; Rumbaugh, Malia; Toga, Arthur W.; 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.; Womack, Kyle; Musiek, Erik; Onyike, Chiadi U.; Riddle, Meghan; Rogalski, Emily; Salloway, Steven; Sha, Sharon J.; Turner, Raymond S.; Wingo, Thomas S.; Wolk, David A.; Carrillo, Maria C.; Dickerson, Bradford C.; Rabinovici, Gil D.; Apostolova, Liana G.; LEADS Consortium; Neurology, School of Medicine
    Introduction: We examined neuropsychiatric symptoms (NPS) and psychotropic medication use in a large sample of individuals with early-onset Alzheimer's disease (EOAD; onset 40-64 years) at the midway point of data collection for the Longitudinal Early-onset Alzheimer's Disease Study (LEADS). Methods: Baseline NPS (Neuropsychiatric Inventory - Questionnaire; Geriatric Depression Scale) and psychotropic medication use from 282 participants enrolled in LEADS were compared across diagnostic groups - amyloid-positive EOAD (n = 212) and amyloid negative early-onset non-Alzheimer's disease (EOnonAD; n = 70). Results: Affective behaviors were the most common NPS in EOAD at similar frequencies to EOnonAD. Tension and impulse control behaviors were more common in EOnonAD. A minority of participants were using psychotropic medications, and use was higher in EOnonAD. Discussion: Overall NPS burden and psychotropic medication use were higher in EOnonAD than EOAD participants. Future research will investigate moderators and etiological drivers of NPS, and NPS differences in EOAD versus late-onset AD. Keywords: early-onset Alzheimer's disease; early-onset dementia; mild cognitive impairment; neuropharmacology; neuropsychiatric symptoms; psychotropic medications.
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    Cerebrospinal fluid biomarkers in the Longitudinal Early-onset Alzheimer's Disease Study
    (Wiley, 2023) Dage, Jeffrey L.; Eloyan, Ani; Thangarajah, Maryanne; Hammers, Dustin B.; Fagan, Anne M.; Gray, Julia D.; Schindler, Suzanne E.; Snoddy, Casey; Nudelman, Kelly N. H.; Faber, Kelley M.; Foroud, Tatiana; Aisen, Paul; Griffin, Percy; Grinberg, Lea T.; Iaccarino, Leonardo; Kirby, Kala; Kramer, Joel; Koeppe, Robert; Kukull, Walter A.; La Joie, Renaud; Mundada, Nidhi S.; Murray, Melissa E.; Rumbaugh, Malia; Soleimani-Meigooni, David N.; Toga, Arthur W.; Touroutoglou, Alexandra; Vemuri, Prashanthi; Atri, Alireza; Beckett, Laurel A.; Day, Gregory S.; Graff-Radford, Neill R.; Duara, Ranjan; Honig, Lawrence S.; Jones, David T.; Masdeu, Joseph C.; Mendez, Mario F.; Musiek, Erik; Onyike, Chiadi U.; Riddle, Meghan; Rogalski, Emily; Salloway, Stephen; Sha, Sharon J.; Turner, Raymond S.; Wingo, Thomas S.; Wolk, David A.; Womack, Kyle B.; Carrillo, Maria C.; Dickerson, Bradford C.; Rabinovici, Gil D.; Apostolova, Liana G.; LEADS Consortium; Neurology, School of Medicine
    Introduction: One goal of the Longitudinal Early Onset Alzheimer's Disease Study (LEADS) is to define the fluid biomarker characteristics of early-onset Alzheimer's disease (EOAD). Methods: Cerebrospinal fluid (CSF) concentrations of Aβ1-40, Aβ1-42, total tau (tTau), pTau181, VILIP-1, SNAP-25, neurogranin (Ng), neurofilament light chain (NfL), and YKL-40 were measured by immunoassay in 165 LEADS participants. The associations of biomarker concentrations with diagnostic group and standard cognitive tests were evaluated. Results: Biomarkers were correlated with one another. Levels of CSF Aβ42/40, pTau181, tTau, SNAP-25, and Ng in EOAD differed significantly from cognitively normal and early-onset non-AD dementia; NfL, YKL-40, and VILIP-1 did not. Across groups, all biomarkers except SNAP-25 were correlated with cognition. Within the EOAD group, Aβ42/40, NfL, Ng, and SNAP-25 were correlated with at least one cognitive measure. Discussion: This study provides a comprehensive analysis of CSF biomarkers in sporadic EOAD that can inform EOAD clinical trial design.
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    Characterization of the heterogeneity of amyloid‐PET‐negative patients with a clinical diagnosis of sporadic early‐onset AD: an FDG‐PET study in the LEADS cohort
    (Wiley, 2025-01-09) Lagarde, Julien; Schonhaut, Daniel R.; Maiti, Piyush; Zhang, Jiaxiuxiu; Soleimani-Meigooni, David N.; Zeltzer, Ehud; Windon, Charles; Hammers, Dustin B.; Dage, Jeffrey L.; Nudelman, Kelly N.; Eloyan, Ani; Koeppe, Robert A.; Carrillo, Maria C.; Touroutoglou, Alexandra; Vemuri, Prashanthi; Dickerson, Bradford C.; Apostolova, Liana G.; Rabinovici, Gil D.; La Joie, Renaud; Neurology, School of Medicine
    Background Diagnosing sporadic early‐onset AD (EOAD, age‐at‐onset<65) is challenging: in the multi‐center Longitudinal Early‐onset Alzheimer’s Disease Study, ∼25% of patients with clinically diagnosed EOAD are amyloid‐PET‐negative. Here we used FDG‐PET to characterize the heterogeneity of hypometabolic profiles in these patients and better identify underlying etiologies. Method Seventy‐four amyloid‐PET‐negative patients with clinical diagnosis of sporadic EOAD (MCI or mild dementia stage) underwent FDG‐PET. Patients were classified as having normal or hypometabolic FDG‐PET based on a data‐driven approach that compared each patient to a group of 61 age‐matched amyloid‐PET‐negative controls using 12 methodological combinations (3 reference regions, 2 voxel‐level thresholds, 2 outlier detection methods). We then assessed clinical and demographic differences between patients with normal versus hypometabolic FDG‐PET, and further compared groups using independent biomarkers of neurodegeneration (structural MRI and fluid biomarkers). Finally, we applied hierarchical clustering to hypometabolic FDG‐PET scans to identify patterns of hypometabolism. Result Thirty‐six amyloid‐negative patients (49%) had hypometabolic FDG‐PET scans. They were older and more severely impaired across most cognitive domains than patients with normal FDG‐PET (Table 1). They also had reduced hippocampal volumes and cortical thickness (Figure 1A), higher plasma and CSF neurofilament light chain (NfL) levels, and elevated plasma GFAP compared to patients with normal FDG‐PET (Figure 1B). In contrast, the latter, who had intermediate cognitive scores between hypometabolic patients and controls, had MRI and fluid biomarker levels in the range of controls (Figure 1). In hypometabolic patients, hierarchical clustering identified four profiles: i) anterior temporal extending to temporo‐parietal and frontal regions (n = 5), ii) anterior temporal and orbitofrontal (n = 11), iii) occipito‐parietal (n = 6), and iv) lateral frontal and parietal (n = 14) (Figure 2). Genetic testing identified two patients with Frontotemporal Lobar Degeneration (FTLD)‐associated pathogenic variants, both considered hypometabolic and assigned to the first (MAPT) and second (c9orf72) metabolic profiles. Conclusion Fifty‐one percent of amyloid‐negative patients had normal FDG‐PET: they had milder clinical impairment, normal MRI measures, and normal NfL values, suggesting non‐neurodegenerative etiologies. Patients with abnormal FDG showed heterogeneous hypometabolic patterns suggestive of multiple etiologies including Lewy body disease, FTLD or corticobasal degeneration. Longitudinal follow‐up to autopsy will ultimately clarify the amyloid‐negative clinical mimics of sporadic EOAD.
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    Cognitive clusters in sporadic early‐onset Alzheimer’s disease patients from the LEADS study
    (Wiley, 2025-01-09) Logan, Paige E.; Lane, Kathleen A.; Gao, Sujuan; Eloyan, Ani; Taurone, Alexander; Thangarajah, Maryanne; Touroutoglou, Alexandra; Vemuri, Prashanthi; Dage, Jeffrey L.; Nudelman, Kelly N.; Carrillo, Maria C.; Dickerson, Bradford C.; Rabinovici, Gil D.; Apostolova, Liana G.; Hammers, Dustin B.; LEADS Consortium; Neurology, School of Medicine
    Background Early‐onset Alzheimer’s disease (EOAD) occurs before age 65 and has more diverse disease presentations than late‐onset AD. To improve our understanding of phenotypic heterogeneity among EOAD individuals, we analyzed cognitive scores using data‐driven statistical analysis. Method Baseline cognitive data from 286 sporadic EOAD individuals from the Longitudinal EOAD study (LEADS) were transformed to z‐scores using data from 95 cognitively normal (CN) individuals. Cognitive composites were generated for domains of memory, language, speed/attention, visuospatial, and executive function. Residuals from linear regression models on Z‐scores adjusted for age, sex, and education were obtained. Cluster analysis using the Ward method on the cognitive domain residuals was performed and scree plot using the pseudo T‐squared determined the optimal number of clusters for the EOAD sample. We also compared gray matter density (GMD) of each EOAD cluster to CN participants using voxel‐wise multiple linear regressions. Results Three clusters of cognitive performance were identified from the EOAD sample. Disease duration was not significantly different across clusters. Using a z‐score of ‐1.5 SD as the impairment threshold, all clusters were impaired across most domains (Table 1). Cluster‐3 was more impaired than cluster‐2 in all domains (Table 2; all p<.0001), and in all domains except episodic memory compared to cluster‐1 (all p<.01). Cluster‐1 (n = 71; 85.9% amnestic) was most impaired in executive function, visuospatial, and speed/attention. Cluster‐2 (n = 133; 88.7% amnestic) was most impaired in episodic memory. Cluster‐3 (n = 82; 69.5% amnestic) was most impaired in executive function, visuospatial, and speed/attention (Table 1). 3D‐comparisons showed all EOAD clusters had reduced GMD compared to CN. Cluster‐1 and cluster‐3 both showed widespread atrophy, with cluster‐3 being more severe. Cluster‐2 showed the most atrophy in the temporal and parietal lobes (Figure 1). Conclusion We identified heterogeneity in cognitive patterns among sporadic EOAD individuals. Cluster‐3 appeared to reflect widespread impairment, and cluster‐2 represented an amnestic‐only presentation. Despite comparable disease duration, some EOAD patients progress faster, while some are more resilient. 3D‐comparisons showed neurodegenerative changes affecting brain regions responsible for respective impaired cognitive functions in each cluster (e.g., cluster‐2 is primarily amnestic‐impaired and has temporoparietal atrophy). Future work should explore amyloid‐PET and tau‐PET burden.
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    Comparison of CSF phosphorylated tau 181 and 217 for cognitive decline
    (Wiley, 2022) Mielke, Michelle M.; Aakre, Jeremiah A.; Algeciras-Schimnich, Alicia; Proctor, Nicholas K.; Machulda, Mary M.; Eichenlaub, Udo; Knopman, David S.; Vemuri, Prashanthi; Graff-Radford, Jonathan; Jac, Clifford R., Jr.; Petersen, Ronald C.; Dage, Jeffrey L.; Neurology, School of Medicine
    Introduction: The prognostic utility of cerebrospinal fluid (CSF) phosphorylated tau 217 (p-tau217) and p-tau181 is not understood. Methods: Analyses included 753 Mayo Clinic Study on Aging participants (median age = 71.6; 57% male). CSF amyloid beta (Aβ)42 and p-tau181 were measured with Elecsys immunoassays. CSF p-tau181 and p-tau217 were also measured with Meso Scale Discovery (MSD). We used Cox proportional hazards models for risk of mild cognitive impairment (MCI) and linear mixed models for risk of global and domain-specific cognitive decline and cortical thickness. Analyses were stratified by elevated brain amyloid based on CSF Aβ42 or amyloid positron emission tomography for those with imaging. Results: CSF p-tau217 was superior to p-tau181 for the diagnosis of Alzheimer's disease (AD) pathology. CSF MSD p-tau181 and p-tau217 were associated with risk of MCI among amyloid-positive individuals. Differences between CSF p-tau measures predicting cortical thickness were subtle. Discussion: There are subtle differences for CSF p-tau217 and p-tau181 as prognostic AD markers.
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    Comparison of Plasma Phosphorylated Tau Species With Amyloid and Tau Positron Emission Tomography, Neurodegeneration, Vascular Pathology, and Cognitive Outcomes
    (American Medical Association, 2021) Mielke, Michelle M.; Frank, Ryan D.; Dage, Jeffrey L.; Jeromin, Andreas; Ashton, Nicholas J.; Blennow, Kaj; Karikari, Thomas K.; Vanmechelen, Eugene; Zetterberg, Henrik; Algeciras-Schimnich, Alicia; Knopman, David S.; Lowe, Val; Bu, Guojun; Vemuri, Prashanthi; Graff-Radford, Jonathan; Jack, Clifford R., Jr.; Petersen, Ronald C.; Neurology, School of Medicine
    Importance: Cerebrospinal fluid phosphorylated tau (p-tau) 181, p-tau217, and p-tau231 are associated with neuropathological outcomes, but a comparison of these p-tau isoforms in blood samples is needed. Objective: To conduct a head-to-head comparison of plasma p-tau181 and p-tau231 measured on the single-molecule array (Simoa) platform and p-tau181 and p-tau217 measured on the Meso Scale Discovery (MSD) platform on amyloid and tau positron emission tomography (PET) measures, neurodegeneration, vascular pathology, and cognitive outcomes. Design, setting, and participants: This study included data from the Mayo Clinic Study on Aging collected from March 1, 2015, to September 30, 2017, and analyzed between December 15, 2020, and May 17, 2021. Associations between the 4 plasma p-tau measures and dichotomous amyloid PET, metaregion of interest tau PET, and entorhinal cortex tau PET were analyzed using logistic regression models; the predictive accuracy was summarized using area under the receiver operating characteristic curve (AUROC) statistic. Of 1329 participants without dementia and with p-tau181 and p-tau217 on MSD, 200 participants with plasma p-tau181 and p-tau231 on Simoa and magnetic resonance imaging and amyloid and tau PET data at the same study visit were eligible. Main outcomes and measures: Primary outcomes included amyloid (greater than 1.48 standardized uptake value ratio) and tau PET, white matter hyperintensities, white matter microstructural integrity (fractional anisotropy genu of corpus callosum and hippocampal cingulum bundle), and cognition. Results: Of 200 included participants, 101 (50.5%) were male, and the median (interquartile range [IQR]) age was 79.5 (71.1-84.1) years. A total of 177 were cognitively unimpaired (CU) and 23 had mild cognitive impairment. Compared with amyloid-negative CU participants, among amyloid-positive CU participants, the median (IQR) Simoa p-tau181 measure was 49% higher (2.58 [2.00-3.72] vs 1.73 [1.45-2.13] pg/mL), MSD p-tau181 measure was 53% higher (1.22 [0.91-1.56] vs 0.80 [0.66-0.97] pg/mL), MSD p-tau217 measure was 77% higher (0.23 [0.17-0.34] vs 0.13 [0.09-0.18] pg/mL), and Simoa p-tau231 measure was 49% higher (20.21 [15.60-25.41] vs 14.27 [11.27-18.10] pg/mL). There were no differences between the p-tau species for amyloid PET and tau PET metaregions of interest. However, among CU participants, both MSD p-tau181 and MSD p-tau217 more accurately predicted abnormal entorhinal cortex tau PET than Simoa p-tau181 (MSD p-tau181: AUROC, 0.80 vs 0.70; P = .046; MSD p-tau217: AUROC, 0.81 vs 0.70; P = .04). MSD p-tau181 and p-tau217 and Simoa p-tau181, but not p-tau231, were associated with greater white matter hyperintensity volume and lower white matter microstructural integrity. Conclusions and relevance: In this largely presymptomatic population, these results suggest subtle differences across plasma p-tau species and platforms for the prediction of amyloid and tau PET and magnetic resonance imaging measures of cerebrovascular and Alzheimer-related pathology.
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    CYP1B1-RMDN2 Alzheimer's disease endophenotype locus identified for cerebral tau PET
    (Springer Nature, 2024-09-20) Nho, Kwangsik; Risacher, Shannon L.; Apostolova, Liana G.; Bice, Paula J.; Brosch, Jared R.; Deardorff, Rachael; Faber, Kelley; Farlow, Martin R.; Foroud, Tatiana; Gao, Sujuan; Rosewood, Thea; Kim, Jun Pyo; Nudelman, Kelly; Yu, Meichen; Aisen, Paul; Sperling, Reisa; Hooli, Basavaraj; Shcherbinin, Sergey; Svaldi, Diana; Jack, Clifford R., Jr.; Jagust, William J.; Landau, Susan; Vasanthakumar, Aparna; Waring, Jeffrey F.; Doré, Vincent; Laws, Simon M.; Masters, Colin L.; Porter, Tenielle; Rowe, Christopher C.; Villemagne, Victor L.; Dumitrescu, Logan; Hohman, Timothy J.; Libby, Julia B.; Mormino, Elizabeth; Buckley, Rachel F.; Johnson, Keith; Yang, Hyun-Sik; Petersen, Ronald C.; Ramanan, Vijay K.; Ertekin-Taner, Nilüfer; Vemuri, Prashanthi; Cohen, Ann D.; Fan, Kang-Hsien; Kamboh, M. Ilyas; Lopez, Oscar L.; Bennett, David A.; Ali, Muhammad; Benzinger, Tammie; Cruchaga, Carlos; Hobbs, Diana; De Jager, Philip L.; Fujita, Masashi; Jadhav, Vaishnavi; Lamb, Bruce T.; Tsai, Andy P.; Castanho, Isabel; Mill, Jonathan; Weiner, Michael W.; Alzheimer’s Disease Neuroimaging Initiative (ADNI); Department of Defense Alzheimer’s Disease Neuroimaging Initiative (DoD-ADNI); Anti-Amyloid Treatment in Asymptomatic Alzheimer’s Study (A4 Study) and Longitudinal Evaluation of Amyloid Risk and Neurodegeneration (LEARN); Australian Imaging, Biomarker & Lifestyle Study (AIBL); Saykin, Andrew J.; Radiology and Imaging Sciences, School of Medicine
    Determining the genetic architecture of Alzheimer's disease pathologies can enhance mechanistic understanding and inform precision medicine strategies. Here, we perform a genome-wide association study of cortical tau quantified by positron emission tomography in 3046 participants from 12 independent studies. The CYP1B1-RMDN2 locus is associated with tau deposition. The most significant signal is at rs2113389, explaining 4.3% of the variation in cortical tau, while APOE4 rs429358 accounts for 3.6%. rs2113389 is associated with higher tau and faster cognitive decline. Additive effects, but no interactions, are observed between rs2113389 and diagnosis, APOE4, and amyloid beta positivity. CYP1B1 expression is upregulated in AD. rs2113389 is associated with higher CYP1B1 expression and methylation levels. Mouse model studies provide additional functional evidence for a relationship between CYP1B1 and tau deposition but not amyloid beta. These results provide insight into the genetic basis of cerebral tau deposition and support novel pathways for therapeutic development in AD.
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    Global neuropathologic severity of Alzheimer's disease and locus coeruleus vulnerability influences plasma phosphorylated tau levels
    (Springer, 2022-12-27) Murray, Melissa E.; Moloney, Christina M.; Kouri, Naomi; Syrjanen, Jeremy A.; Matchett, Billie J.; Rothberg, Darren M.; Tranovich, Jessica F.; Hicks Sirmans, Tiffany N.; Wiste, Heather J.; Boon, Baayla D. C.; Nguyen, Aivi T.; Reichard, R. Ross; Dickson, Dennis W.; Lowe, Val J.; Dage, Jeffrey L.; Petersen, Ronald C.; Jack, Clifford R., Jr.; Knopman , David S.; Vemuri, Prashanthi; Graff-Radford, Jonathan; Mielke, Michelle M.; Neurology, School of Medicine
    Background Advances in ultrasensitive detection of phosphorylated tau (p-tau) in plasma has enabled the use of blood tests to measure Alzheimer’s disease (AD) biomarker changes. Examination of postmortem brains of participants with antemortem plasma p-tau levels remains critical to understanding comorbid and AD-specific contribution to these biomarker changes. Methods We analyzed 35 population-based Mayo Clinic Study of Aging participants with plasma p-tau at threonine 181 and threonine 217 (p-tau181, p-tau217) available within 3 years of death. Autopsied participants included cognitively unimpaired, mild cognitive impairment, AD dementia, and non-AD neurodegenerative disorders. Global neuropathologic scales of tau, amyloid-β, TDP-43, and cerebrovascular disease were examined. Regional digital pathology measures of tau (phosphorylated threonine 181 and 217 [pT181, pT217]) and amyloid-β (6F/3D) were quantified in hippocampus and parietal cortex. Neurotransmitter hubs reported to influence development of tangles (nucleus basalis of Meynert) and amyloid-β plaques (locus coeruleus) were evaluated. Results The strongest regional associations were with parietal cortex for tau burden (p-tau181 R = 0.55, p = 0.003; p-tau217 R = 0.66, p < 0.001) and amyloid-β burden (p-tau181 R = 0.59, p < 0.001; p-tau217 R = 0.71, p < 0.001). Linear regression analysis of global neuropathologic scales explained 31% of variability in plasma p-tau181 (Adj. R2 = 0.31) and 59% in plasma p-tau217 (Adj. R2 = 0.59). Neither TDP-43 nor cerebrovascular disease global scales independently contributed to variability. Global scales of tau pathology (β-coefficient = 0.060, p = 0.016) and amyloid-β pathology (β-coefficient = 0.080, p < 0.001) independently predicted plasma p-tau217 when modeled together with co-pathologies, but only amyloid-β (β-coefficient = 0.33, p = 0.021) significantly predicted plasma p-tau181. While nucleus basalis of Meynert neuron count/mm2 was not associated with plasma p-tau levels, a lower locus coeruleus neuron count/mm2 was associated with higher plasma p-tau181 (R = -0.50, p = 0.007) and higher plasma p-tau217 (R = -0.55, p = 0.002). Cognitive scores (Adj. R2 = 0.25–0.32) were predicted by the global tau scale, but not by the global amyloid-β scale or plasma p-tau when modeled simultaneously. Conclusions Higher soluble plasma p-tau levels may be the result of an intersection between insoluble deposits of amyloid-β and tau accumulation in brain, and may be associated with locus coeruleus degeneration.