Browsing by Author "Perrin, Richard J."

Now showing 1 - 10 of 35
  • Thumbnail Image
    Item
    15 Years of Longitudinal Genetic, Clinical, Cognitive, Imaging, and Biochemical Measures in DIAN
    (medRxiv, 2024-08-09) Daniels, Alisha J.; McDade, Eric; Llibre-Guerra, Jorge J.; Xiong, Chengjie; Perrin, Richard J.; Ibanez, Laura; Supnet-Bell, Charlene; Cruchaga, Carlos; Goate, Alison; Renton, Alan E.; Benzinger, Tammie L. S.; Gordon, Brian A.; Hassenstab, Jason; Karch, Celeste; Popp, Brent; Levey, Allan; Morris, John; Buckles, Virginia; Allegri, Ricardo F.; Chrem, Patricio; Berman, Sarah B.; Chhatwal, Jasmeer P.; Farlow, Martin R.; Fox, Nick C.; Day, Gregory S.; Ikeuchi, Takeshi; Jucker, Mathias; Lee, Jae-Hong; Levin, Johannes; Lopera, Francisco; Takada, Leonel; Sosa, Ana Luisa; Martins, Ralph; Mori, Hiroshi; Noble, James M.; Salloway, Stephen; Huey, Edward; Rosa-Neto, Pedro; Sánchez-Valle, Raquel; Schofield, Peter R.; Roh, Jee Hoon; Bateman, Randall J.; Dominantly Inherited Alzheimer Network; Neurology, School of Medicine
    This manuscript describes and summarizes the Dominantly Inherited Alzheimer Network Observational Study (DIAN Obs), highlighting the wealth of longitudinal data, samples, and results from this human cohort study of brain aging and a rare monogenic form of Alzheimer's disease (AD). DIAN Obs is an international collaborative longitudinal study initiated in 2008 with support from the National Institute on Aging (NIA), designed to obtain comprehensive and uniform data on brain biology and function in individuals at risk for autosomal dominant AD (ADAD). ADAD gene mutations in the amyloid protein precursor (APP), presenilin 1 (PSEN1), or presenilin 2 (PSEN2) genes are deterministic causes of ADAD, with virtually full penetrance, and a predictable age at symptomatic onset. Data and specimens collected are derived from full clinical assessments, including neurologic and physical examinations, extensive cognitive batteries, structural and functional neuro-imaging, amyloid and tau pathological measures using positron emission tomography (PET), flurordeoxyglucose (FDG) PET, cerebrospinal fluid and blood collection (plasma, serum, and whole blood), extensive genetic and multi-omic analyses, and brain donation upon death. This comprehensive evaluation of the human nervous system is performed longitudinally in both mutation carriers and family non-carriers, providing one of the deepest and broadest evaluations of the human brain across decades and through AD progression. These extensive data sets and samples are available for researchers to address scientific questions on the human brain, aging, and AD.
  • Thumbnail Image
    Item
    A cross‐sectional study of α‐synuclein seed amplification assay in Alzheimer's disease neuroimaging initiative: Prevalence and associations with Alzheimer's disease biomarkers and cognitive function
    (Wiley, 2024) Tosun, Duygu; Hausle, Zachary; Iwaki, Hirotaka; Thropp, Pamela; Lamoureux, Jennifer; Lee, Edward B.; MacLeod, Karen; McEvoy, Sean; Nalls, Michael; Perrin, Richard J.; Saykin, Andrew J.; Shaw, Leslie M.; Singleton, Andrew B.; Lebovitz, Russ; Weiner, Michael W.; Blauwendraat, Cornelis; Alzheimer’s Disease Neuroimaging Initiative; Radiology and Imaging Sciences, School of Medicine
    Introduction: Alzheimer's disease (AD) pathology is defined by β-amyloid (Aβ) plaques and neurofibrillary tau, but Lewy bodies (LBs; 𝛼-synuclein aggregates) are a common co-pathology for which effective biomarkers are needed. Methods: A validated α-synuclein Seed Amplification Assay (SAA) was used on recent cerebrospinal fluid (CSF) samples from 1638 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants, 78 with LB-pathology confirmation at autopsy. We compared SAA outcomes with neuropathology, Aβ and tau biomarkers, risk-factors, genetics, and cognitive trajectories. Results: SAA showed 79% sensitivity and 97% specificity for LB pathology, with superior performance in identifying neocortical (100%) compared to limbic (57%) and amygdala-predominant (60%) LB-pathology. SAA+ rate was 22%, increasing with disease stage and age. Higher Aβ burden but lower CSF p-tau181 associated with higher SAA+ rates, especially in dementia. SAA+ affected cognitive impairment in MCI and Early-AD who were already AD biomarker positive. Discussion: SAA is a sensitive, specific marker for LB-pathology. Its increase in prevalence with age and AD stages, and its association with AD biomarkers, highlights the clinical importance of α-synuclein co-pathology in understanding AD's nature and progression. Highlights: SAA shows 79% sensitivity, 97% specificity for LB-pathology detection in AD. SAA positivity prevalence increases with disease stage and age. Higher Aβ burden, lower CSF p-tau181 linked with higher SAA+ rates in dementia. SAA+ impacts cognitive impairment in early disease stages. Study underpins need for wider LB-pathology screening in AD treatment.
  • Thumbnail Image
    Item
    A peptide-centric quantitative proteomics dataset for the phenotypic assessment of Alzheimer's disease
    (Springer Nature, 2023-04-14) Merrihew, Gennifer E.; Park, Jea; Plubell, Deanna; Searle, Brian C.; Keene, C. Dirk; Larson, Eric B.; Bateman, Randall; Perrin, Richard J.; Chhatwal, Jasmeer P.; Farlow, Martin R.; McLean, Catriona A.; Ghetti, Bernardino; Newell, Kathy L.; Frosch, Matthew P.; Montine, Thomas J.; MacCoss, Michael J.; Neurology, School of Medicine
    Alzheimer's disease (AD) is a looming public health disaster with limited interventions. Alzheimer's is a complex disease that can present with or without causative mutations and can be accompanied by a range of age-related comorbidities. This diverse presentation makes it difficult to study molecular changes specific to AD. To better understand the molecular signatures of disease we constructed a unique human brain sample cohort inclusive of autosomal dominant AD dementia (ADD), sporadic ADD, and those without dementia but with high AD histopathologic burden, and cognitively normal individuals with no/minimal AD histopathologic burden. All samples are clinically well characterized, and brain tissue was preserved postmortem by rapid autopsy. Samples from four brain regions were processed and analyzed by data-independent acquisition LC-MS/MS. Here we present a high-quality quantitative dataset at the peptide and protein level for each brain region. Multiple internal and external control strategies were included in this experiment to ensure data quality. All data are deposited in the ProteomeXchange repositories and available from each step of our processing.
  • Thumbnail Image
    Item
    A trial of gantenerumab or solanezumab in dominantly inherited Alzheimer's disease
    (Springer Nature, 2021) Salloway, Stephen; Farlow, Martin; McDade, Eric; Clifford, David B.; Wang, Guoqiao; Llibre-Guerra, Jorge J.; Hitchcock, Janice M.; Mills, Susan L.; Santacruz, Anna M.; Aschenbrenner, Andrew J.; Hassenstab, Jason; Benzinger, Tammie L.S.; Gordon, Brian A.; Fagan, Anne M.; Coalier, Kelley A.; Cruchaga, Carlos; Goate, Alison A.; Perrin, Richard J.; Xiong, Chengjie; Li, Yan; Morris, John C.; Snider, B. Joy; Mummery, Catherine; Surti, G. Mustafa; Hannequin, Didier; Wallon, David; Berman, Sarah B.; Lah, James J.; Jimenez-Velazquez, Ivonne Z.; Roberson, Erik D.; van Dyck, Christopher H.; Honig, Lawrence S.; Sánchez-Valle, Raquel; Brooks, William S.; Gauthier, Serge; Galasko, Douglas R.; Masters, Colin L.; Brosch, Jared R.; Hsiung, Ging-Yuek Robin; Jayadev, Suman; Formaglio, Maité; Masellis, Mario; Clarnette, Roger; Pariente, Jérémie; Dubois, Bruno; Pasquier, Florence; Jack, Clifford R., Jr.; Koeppe, Robert; Snyder, Peter J.; Aisen, Paul S.; Thomas, Ronald G.; Berry, Scott M.; Wendelberger, Barbara A.; Andersen, Scott W.; Holdridge, Karen C.; Mintun, Mark A.; Yaari, Roy; Sims, John R.; Baudler, Monika; Delmar, Paul; Doody, Rachelle S.; Fontoura, Paulo; Giacobino, Caroline; Kerchner, Geoffrey A.; Bateman, Randall J.; Dominantly Inherited Alzheimer Network–Trials Unit; Neurology, School of Medicine
    Dominantly inherited Alzheimer's disease (DIAD) causes predictable biological changes decades before the onset of clinical symptoms, enabling testing of interventions in the asymptomatic and symptomatic stages to delay or slow disease progression. We conducted a randomized, placebo-controlled, multi-arm trial of gantenerumab or solanezumab in participants with DIAD across asymptomatic and symptomatic disease stages. Mutation carriers were assigned 3:1 to either drug or placebo and received treatment for 4-7 years. The primary outcome was a cognitive end point; secondary outcomes included clinical, cognitive, imaging and fluid biomarker measures. Fifty-two participants carrying a mutation were assigned to receive gantenerumab, 52 solanezumab and 40 placebo. Both drugs engaged their Aβ targets but neither demonstrated a beneficial effect on cognitive measures compared to controls. The solanezumab-treated group showed a greater cognitive decline on some measures and did not show benefits on downstream biomarkers. Gantenerumab significantly reduced amyloid plaques, cerebrospinal fluid total tau, and phospho-tau181 and attenuated increases of neurofilament light chain. Amyloid-related imaging abnormalities edema was observed in 19.2% (3 out of 11 were mildly symptomatic) of the gantenerumab group, 2.5% of the placebo group and 0% of the solanezumab group. Gantenerumab and solanezumab did not slow cognitive decline in symptomatic DIAD. The asymptomatic groups showed no cognitive decline; symptomatic participants had declined before reaching the target doses.
  • Thumbnail Image
    Item
    Amyloid-Related Imaging Abnormalities in the DIAN-TU-001 Trial of Gantenerumab and Solanezumab: Lessons from a Trial in Dominantly Inherited Alzheimer Disease
    (Wiley, 2022) Joseph-Mathurin, Nelly; Llibre-Guerra, Jorge J.; Li, Yan; McCullough, Austin A.; Hofmann, Carsten; Wojtowicz, Jakub; Park, Ethan; Wang, Guoqiao; Preboske, Gregory M.; Wang, Qing; Gordon, Brian A.; Chen, Charles D.; Flores, Shaney; Aggarwal, Neelum T.; Berman, Sarah B.; Bird, Thomas D.; Black, Sandra E.; Borowski, Bret; Brooks, William S.; Chhatwal, Jasmeer P.; Clarnette, Roger; Cruchaga, Carlos; Fagan, Anne M.; Farlow, Martin; Fox, Nick C.; Gauthier, Serge; Hassenstab, Jason; Hobbs, Diana A.; Holdridge, Karen C.; Honig, Lawrence S.; Hornbeck, Russ C.; Hsiung, Ging-Yuek R.; Jack, Clifford R., Jr.; Jimenez-Velazquez, Ivonne Z.; Jucker, Mathias; Klein, Gregory; Levin, Johannes; Mancini, Michele; Masellis, Mario; McKay, Nicole S.; Mummery, Catherine J.; Ringman, John M.; Shimada, Hiroyuki; Snider, B. Joy; Suzuki, Kazushi; Wallon, David; Xiong, Chengjie; Yaari, Roy; McDade, Eric; Perrin, Richard J.; Bateman, Randall J.; Salloway, Stephen P.; Benzinger, Tammie L. S.; Clifford, David B.; Dominantly Inherited Alzheimer Network Trials Unit; Neurology, School of Medicine
    Objective: To determine the characteristics of participants with amyloid-related imaging abnormalities (ARIA) in a trial of gantenerumab or solanezumab in dominantly inherited Alzheimer disease (DIAD). Methods: 142 DIAD mutation carriers received either gantenerumab SC (n = 52), solanezumab IV (n = 50), or placebo (n = 40). Participants underwent assessments with the Clinical Dementia Rating® (CDR®), neuropsychological testing, CSF biomarkers, β-amyloid positron emission tomography (PET), and magnetic resonance imaging (MRI) to monitor ARIA. Cross-sectional and longitudinal analyses evaluated potential ARIA-related risk factors. Results: Eleven participants developed ARIA-E, including 3 with mild symptoms. No ARIA-E was reported under solanezumab while gantenerumab was associated with ARIA-E compared to placebo (odds ratio [OR] = 9.1, confidence interval [CI][1.2, 412.3]; p = 0.021). Under gantenerumab, APOE-ɛ4 carriers were more likely to develop ARIA-E (OR = 5.0, CI[1.0, 30.4]; p = 0.055), as were individuals with microhemorrhage at baseline (OR = 13.7, CI[1.2, 163.2]; p = 0.039). No ARIA-E was observed at the initial 225 mg/month gantenerumab dose, and most cases were observed at doses >675 mg. At first ARIA-E occurrence, all ARIA-E participants were amyloid-PET+, 60% were CDR >0, 60% were past their estimated year to symptom onset, and 60% had also incident ARIA-H. Most ARIA-E radiologically resolved after dose adjustment and developing ARIA-E did not significantly increase odds of trial discontinuation. ARIA-E was more frequently observed in the occipital lobe (90%). ARIA-E severity was associated with age at time of ARIA-E. Interpretation: In DIAD, solanezumab was not associated with ARIA. Gantenerumab dose over 225 mg increased ARIA-E risk, with additional risk for individuals APOE-ɛ4(+) or with microhemorrhage. ARIA-E was reversible on MRI in most cases, generally asymptomatic, without additional risk for trial discontinuation.
  • Thumbnail Image
    Item
    Axonal damage and inflammation response are biological correlates of decline in small-world values: a cohort study in autosomal dominant Alzheimer's disease
    (Oxford University Press, 2024-10-09) Vermunt, Lisa; Sutphen, Courtney L.; Dicks, Ellen; de Leeuw, Diederick M.; Allegri, Ricardo F.; Berman, Sarah B.; Cash, David M.; Chhatwal, Jasmeer P.; Cruchaga, Carlos; Day, Gregory S.; Ewers, Michael; Farlow, Martin R.; Fox, Nick C.; Ghetti, Bernardino; Graff-Radford, Neill R.; Hassenstab, Jason; Jucker, Mathias; Karch, Celeste M.; Kuhle, Jens; Laske, Christoph; Levin, Johannes; Masters, Colin L.; McDade, Eric; Mori, Hiroshi; Morris, John C.; Perrin, Richard J.; Preische, Oliver; Schofield, Peter R.; Suárez-Calvet, Marc; Xiong, Chengjie; Scheltens, Philip; Teunissen, Charlotte E.; Visser, Pieter Jelle; Bateman, Randall J.; Benzinger, Tammie L. S.; Fagan, Anne M.; Gordon, Brian A.; Tijms, Betty M.; Pathology and Laboratory Medicine, School of Medicine
    The grey matter of the brain develops and declines in coordinated patterns during the lifespan. Such covariation patterns of grey matter structure can be quantified as grey matter networks, which can be measured with magnetic resonance imaging. In Alzheimer's disease, the global organization of grey matter networks becomes more random, which is captured by a decline in the small-world coefficient. Such decline in the small-world value has been robustly associated with cognitive decline across clinical stages of Alzheimer's disease. The biological mechanisms causing this decline in small-world values remain unknown. Cerebrospinal fluid (CSF) protein biomarkers are available for studying diverse pathological mechanisms in humans and can provide insight into decline. We investigated the relationships between 10 CSF proteins and small-world coefficient in mutation carriers (N = 219) and non-carriers (N = 136) of the Dominantly Inherited Alzheimer Network Observational study. Abnormalities in Amyloid beta, Tau, synaptic (Synaptosome associated protein-25, Neurogranin) and neuronal calcium-sensor protein (Visinin-like protein-1) preceded loss of small-world coefficient by several years, while increased levels in CSF markers for inflammation (Chitinase-3-like protein 1) and axonal injury (Neurofilament light) co-occurred with decreasing small-world values. This suggests that axonal loss and inflammation play a role in structural grey matter network changes.
  • Thumbnail Image
    Item
    Circular RNA detection identifies circPSEN1 alterations in brain specific to autosomal dominant Alzheimer's disease
    (BMC, 2022-03-04) Chen, Hsiang‑Han; Eteleeb, Abdallah; Wang, Ciyang; Fernandez, Maria Victoria; Budde, John P.; Bergmann, Kristy; Norton, Joanne; Wang, Fengxian; Ebl, Curtis; Morris, John C.; Perrin, Richard J.; Bateman, Randall J.; McDade, Eric; Xiong, Chengjie; Goate, Alison; Farlow, Martin; Chhatwal, Jasmeer; Schofield, Peter R.; Chui, Helena; Harari, Oscar; Cruchaga, Carlos; Ibanez, Laura; Dominantly Inherited Alzheimer Network; Neurology, School of Medicine
    Background: Autosomal-dominant Alzheimer's disease (ADAD) is caused by pathogenic mutations in APP, PSEN1, and PSEN2, which usually lead to an early age at onset (< 65). Circular RNAs are a family of non-coding RNAs highly expressed in the nervous system and especially in synapses. We aimed to investigate differences in brain gene expression of linear and circular transcripts from the three ADAD genes in controls, sporadic AD, and ADAD. Methods: We obtained and sequenced RNA from brain cortex using standard protocols. Linear counts were obtained using the TOPMed pipeline; circular counts, using python package DCC. After stringent quality control (QC), we obtained the counts for PSEN1, PSEN2 and APP genes. Only circPSEN1 passed QC. We used DESeq2 to compare the counts across groups, correcting for biological and technical variables. Finally, we performed in-silico functional analyses using the Circular RNA interactome website and DIANA mirPath software. Results: Our results show significant differences in gene counts of circPSEN1 in ADAD individuals, when compared to sporadic AD and controls (ADAD = 21, AD = 253, Controls = 23-ADADvsCO: log2FC = 0.794, p = 1.63 × 10-04, ADADvsAD: log2FC = 0.602, p = 8.22 × 10-04). The high gene counts are contributed by two circPSEN1 species (hsa_circ_0008521 and hsa_circ_0003848). No significant differences were observed in linear PSEN1 gene expression between cases and controls, indicating that this finding is specific to the circular forms. In addition, the high circPSEN1 levels do not seem to be specific to PSEN1 mutation carriers; the counts are also elevated in APP and PSEN2 mutation carriers. In-silico functional analyses suggest that circPSEN1 is involved in several pathways such as axon guidance (p = 3.39 × 10-07), hippo signaling pathway (p = 7.38 × 10-07), lysine degradation (p = 2.48 × 10-05) or Wnt signaling pathway (p = 5.58 × 10-04) among other KEGG pathways. Additionally, circPSEN1 counts were able to discriminate ADAD from sporadic AD and controls with an AUC above 0.70. Conclusions: Our findings show the differential expression of circPSEN1 is increased in ADAD. Given the biological function previously ascribed to circular RNAs and the results of our in-silico analyses, we hypothesize that this finding might be related to neuroinflammatory events that lead or that are caused by the accumulation of amyloid-beta.
  • Thumbnail Image
    Item
    Comparative Analysis of Alzheimer's Disease Cerebrospinal Fluid Biomarkers Measurement by Multiplex SOMAscan Platform and Immunoassay-Based Approach
    (IOS Press, 2022) Timsina, Jigyasha; Gomez-Fonseca, Duber; Wang, Lihua; Do, Anh; Western, Dan; Alvarez, Ignacio; Aguilar, Miquel; Pastor, Pau; Henson, Rachel L.; Herries, Elizabeth; Xiong, Chengjie; Schindler, Suzanne E.; Fagan, Anne M.; Bateman, Randall J.; Farlow, Martin; Morris, John C.; Perrin, Richard J.; Moulder, Krista; Hassenstab, Jason; Vöglein, Jonathan; Chhatwal, Jasmeer; Mori, Hiroshi; Alzheimer’s Disease Neuroimaging Initiative; Dominantly Inherited Alzheimer Network Consortia; Sung, Yun Ju; Cruchaga, Carlos; Neurology, School of Medicine
    Background: The SOMAscan assay has an advantage over immunoassay-based methods because it measures a large number of proteins in a cost-effective manner. However, the performance of this technology compared to the routinely used immunoassay techniques needs to be evaluated. Objective: We performed comparative analyses of SOMAscan and immunoassay-based protein measurements for five cerebrospinal fluid (CSF) proteins associated with Alzheimer's disease (AD) and neurodegeneration: NfL, Neurogranin, sTREM2, VILIP-1, and SNAP-25. Methods: We compared biomarkers measured in ADNI (N = 689), Knight-ADRC (N = 870), DIAN (N = 115), and Barcelona-1 (N = 92) cohorts. Raw protein values were transformed using z-score in order to combine measures from the different studies. sTREM2 and VILIP-1 had more than one analyte in SOMAscan; all available analytes were evaluated. Pearson's correlation coefficients between SOMAscan and immunoassays were calculated. Receiver operating characteristic curve and area under the curve were used to compare prediction accuracy of these biomarkers between the two platforms. Results: Neurogranin, VILIP-1, and NfL showed high correlation between SOMAscan and immunoassay measures (r > 0.9). sTREM2 had a fair correlation (r > 0.6), whereas SNAP-25 showed weak correlation (r = 0.06). Measures in both platforms provided similar predicted performance for all biomarkers except SNAP-25 and one of the sTREM2 analytes. sTREM2 showed higher AUC for SOMAscan based measures. Conclusion: Our data indicate that SOMAscan performs as well as immunoassay approaches for NfL, Neurogranin, VILIP-1, and sTREM2. Our study shows promise for using SOMAscan as an alternative to traditional immunoassay-based measures. Follow-up investigation will be required for SNAP-25 and additional established biomarkers.
  • Thumbnail Image
    Item
    Comparative neurofilament light chain trajectories in CSF and plasma in autosomal dominant Alzheimer's disease
    (Springer Nature, 2024-11-18) Hofmann, Anna; Häsler, Lisa M.; Lambert, Marius; Kaeser, Stephan A.; Gräber-Sultan, Susanne; Obermüller, Ulrike; Kuder-Buletta, Elke; la Fougere, Christian; Laske, Christoph; Vöglein, Jonathan; Levin, Johannes; Fox, Nick C.; Ryan, Natalie S.; Zetterberg, Henrik; Llibre-Guerra, Jorge J.; Perrin, Richard J.; Ibanez, Laura; Schofield, Peter R.; Brooks, William S.; Day, Gregory S.; Farlow, Martin R.; Allegri, Ricardo F.; Mendez, Patricio Chrem; Ikeuchi, Takeshi; Kasuga, Kensaku; Lee, Jae-Hong; Roh, Jee Hoon; Mori, Hiroshi; Lopera, Francisco; Bateman, Randall J.; McDade, Eric; Gordon, Brian A.; Chhatwal, Jasmeer P.; Jucker, Mathias; Schultz, Stephanie A.; Dominantly Inherited Alzheimer Network; Pathology and Laboratory Medicine, School of Medicine
    Disease-modifying therapies for Alzheimer's disease (AD) are likely to be most beneficial when initiated in the presymptomatic phase. To track the benefit of such interventions, fluid biomarkers are of great importance, with neurofilament light chain protein (NfL) showing promise for monitoring neurodegeneration and predicting cognitive outcomes. Here, we update and complement previous findings from the Dominantly Inherited Alzheimer Network Observational Study by using matched cross-sectional and longitudinal cerebrospinal fluid (CSF) and plasma samples from 567 individuals, allowing timely comparative analyses of CSF and blood trajectories across the entire disease spectrum. CSF and plasma trajectories were similar at presymptomatic stages, discriminating mutation carriers from non-carrier controls 10-20 years before the estimated onset of clinical symptoms, depending on the statistical model used. However, after symptom onset the rate of change in CSF NfL continued to increase steadily, whereas the rate of change in plasma NfL leveled off. Both plasma and CSF NfL changes were associated with grey-matter atrophy, but not with Aβ-PET changes, supporting a temporal decoupling of Aβ deposition and neurodegeneration. These observations support NfL in both CSF and blood as an early marker of neurodegeneration but suggest that NfL measured in the CSF may be better suited for monitoring clinical trial outcomes in symptomatic AD patients.
  • Thumbnail Image
    Item
    Comparing amyloid-β plaque burden with antemortem PiB PET in autosomal dominant and late-onset Alzheimer disease
    (Springer, 2021) Chen, Charles D.; Joseph-Mathurin, Nelly; Sinha, Namita; Zhou, Aihong; Li, Yan; Friedrichsen, Karl; McCullough, Austin; Franklin, Erin E.; Hornbeck, Russ; Gordon, Brian; Sharma, Vijay; Cruchaga, Carlos; Goate, Alison; Karch, Celeste; McDade, Eric; Xiong, Chengjie; Bateman, Randall J.; Ghetti, Bernardino; Ringman, John M.; Chhatwal, Jasmeer; Masters, Colin L.; McLean, Catriona; Lashley, Tammaryn; Su, Yi; Koeppe, Robert; Jack, Clifford; Klunk, William E.; Morris, John C.; Perrin, Richard J.; Cairns, Nigel J.; Benzinger, Tammie L.S.; Pathology and Laboratory Medicine, School of Medicine
    Pittsburgh compound B (PiB) radiotracer for positron emission tomography (PET) imaging can bind to different types of amyloid-β plaques and blood vessels (cerebral amyloid angiopathy). However, the relative contributions of different plaque subtypes (diffuse versus cored/compact) to in vivo PiB PET signal on a region-by-region basis is incompletely understood. Of particular interest is whether the same staging schemes for summarizing amyloid-β burden are appropriate for both late-onset and autosomal dominant forms of Alzheimer disease (LOAD and ADAD). Here we compared antemortem PiB PET with follow-up postmortem estimation of amyloid-β burden using stereologic methods to estimate the relative area fraction of diffuse and cored/compact amyloid-β plaques across 16 brain regions in 15 individuals with ADAD and 14 individuals with LOAD. In ADAD, we found that PiB PET correlated with diffuse plaques in the frontal, parietal, temporal, and striatal regions commonly used to summarize amyloid-β burden in PiB PET, and correlated with both diffuse and cored/compact plaques in the occipital lobe and parahippocampal gyrus. In LOAD, we found that PiB PET correlated with both diffuse and cored/compact plaques in the anterior cingulate, frontal lobe (middle frontal gyrus), and parietal lobe, and showed additional correlations with diffuse plaque in the amygdala and occipital lobe, and with cored/compact plaque in the temporal lobe. Thus, commonly used PiB PET summary regions predominantly reflect diffuse plaque burden in ADAD and a mixture of diffuse and cored/compact plaque burden in LOAD. In direct comparisons of ADAD and LOAD, postmortem stereology identified much greater mean amyloid-β plaque burdens in ADAD versus LOAD across almost all brain regions studied. However, standard PiB PET did not recapitulate these stereologic findings, likely due to non-trivial amyloid-β plaque burdens in ADAD within the cerebellum and brainstem – commonly used reference regions in PiB PET. Our findings suggest that PiB PET summary regions correlate with amyloid-β plaque burden in both ADAD and LOAD; however, they might not be reliable in direct comparisons of regional amyloid-β plaque burden between the two forms of AD.