scholarly journals Amyloidogenic Nanoplaques in Cerebrospinal Fluid: Relationship to Amyloid Brain Uptake and Clinical Alzheimer’s Disease in a Memory Clinic Cohort

2020 ◽  
Vol 77 (2) ◽  
pp. 831-842 ◽  
Author(s):  
Mari Aksnes ◽  
Ebba Glersen Müller ◽  
Ann Tiiman ◽  
Trine Holt Edwin ◽  
Lars Terenius ◽  
...  

Background: Aggregation of amyloid-β (Aβ) is an early pathological event in Alzheimer’s disease (AD). Consequently, measures of pathogenic aggregated Aβ are attractive biomarkers for AD. Here, we use a recently developed Thioflavin-T-Fluorescence Correlation Spectroscopy (ThT-FCS) assay to quantify structured ThT-responsive protein aggregates, so-called nanoplaques, in the cerebrospinal fluid (CSF). Objective: The overall aim of this work was to assess whether ThT-FCS determined CSF nanoplaque levels could predict amyloid brain uptake as determined by 18F-Flutemetamol PET analysis. Further, we assess whether nanoplaque levels could predict clinical AD. Methods: Nanoplaque levels in the CSF from 54 memory clinic patients were compared between sub-groups classified by 18F-Flutemetamol PET as amyloid-positive or amyloid-negative, and by clinical assessment as AD or non-AD. Results: Nanoplaque levels did not differ between amyloid groups and could not predict brain amyloid uptake. However, nanoplaque levels were significantly increased in patients with clinical AD, and were significant predictors for AD when adjusting for age, sex, cognitive function, and apolipoprotein E (APOE) genotype. Conclusion: The concentration of nanoplaques in the CSF differentiates patients with clinical AD from non-AD patients.

2017 ◽  
Vol 50 (18) ◽  
pp. 1061-1066 ◽  
Author(s):  
Madhurima Chatterjee ◽  
Bernd Nöding ◽  
Eline A.J. Willemse ◽  
Marleen J.A. Koel-Simmelink ◽  
Wiesje M. van der Flier ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Mari Aksnes ◽  
Ann Tiiman ◽  
Trine Holt Edwin ◽  
Lars Terenius ◽  
Nenad Bogdanović ◽  
...  

Accurate biomarkers of Alzheimer’s disease (AD) are essential for early diagnosis and intervention. Available biomarkers are not sufficient to permit the monitoring of AD progression over time, and additional biomarkers are required. Measures of aggregated amyloid-β (Aβ) could be useful biomarkers for AD. Here, we investigate whether levels of Thioflavin-T (ThT) positive amyloid aggregates, i.e., nanoplaques, in cerebrospinal fluid (CSF) could serve as useful biomarkers for AD. One-hundred and eighteen memory clinic patients were AT(N) classified, and CSF nanoplaque concentrations were compared between patients on the “Alzheimer’s continuum” (A+ patients) and patients with “Normal AD biomarkers” or “Non-AD pathologic change” (A− patients). CSF nanoplaque concentrations and sizes were quantified using the novel ThT-Fluorescence Correlation Spectroscopy (ThT-FCS) assay, and core biomarkers (Aβ42, total tau and phosphorylated tau) were determined by enzyme-linked immunosorbent assays. We investigated the association between nanoplaque concentrations and core biomarkers, and the diagnostic value of nanoplaque levels. Nanoplaque levels were increased in A+ patients compared to A− patients. Nanoplaque concentrations were negatively associated with Aβ42, but not related to total tau or phosphorylated tau measures. Quantification of nanoplaques did not improve the classification of patients on the Alzheimer’s continuum compared to the core biomarkers alone. Dynamic changes in nanoplaques concentration and size throughout AD stages should be explored in longitudinal studies.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Mari Aksnes ◽  
Hans Christian D. Aass ◽  
Ann Tiiman ◽  
Trine Holt Edwin ◽  
Lars Terenius ◽  
...  

Abstract Background The aggregation of amyloid β (Aβ) is central in the pathogenesis of Alzheimer’s disease (AD). Recently it has been shown that specifically, larger, Thioflavin T-binding Aβ aggregates are associated with increased neuroinflammation and cytokine release. This study was aimed to quantify fibrillary amyloid aggregates, so-called nanoplaques, and investigate their relationship with cytokines in the cerebrospinal fluid (CSF). Methods CSF was collected from 111 patients assessed for cognitive complaints at the Oslo University Hospital Memory Clinic. The patients were grouped based on their amyloid status. The CSF nanoplaque concentration was quantified with the Thioflavin T-fluorescence correlation spectroscopy (ThT-FCS) assay. The levels of nine cytokines (eotaxin-1, granulocyte stimulating factor, interleukin [IL]-6, IL-7, IL-8, monocyte chemoattractant protein-1, gamma-induced protein 10, macrophage inflammatory protein [MIP]-1α, and MIP-1β) were quantified with a magnetic bead-based multiplex assay and read on a Luminex IS 200 instrument. Results There were 49 amyloid-negative and 62 amyloid-positive patients in the cohort; none of the cytokines differed significantly between the amyloid groups. The increased nanoplaque levels were associated with levels of MIP-1β below the lower limit of quantification, and with decreased levels of MIP-1α and IL-8. The associations remained significant when adjusted for age, sex, cognitive function, apolipoprotein ε4 status and CSF core biomarker levels. Conclusion The cytokine levels were not associated with amyloid status in this cohort. The nanoplaque levels were negatively associated with MIP-1β, MIP-1α and IL-8, which is in line with recent findings suggesting that the upregulation of some cytokine markers has a protective role and is negatively associated with AD progression.


2020 ◽  
pp. 1-14
Author(s):  
Yi-Wen Bao ◽  
Anson C.M. Chau ◽  
Patrick Ka-Chun Chiu ◽  
Yat Fung Shea ◽  
Joseph S.K. Kwan ◽  
...  

Background: With the more widespread use of 18F-radioligand-based amyloid-β (Aβ) PET-CT imaging, we evaluated Aβ binding and the utility of neocortical 18F-Flutemetamol standardized uptake value ratio (SUVR) as a biomarker. Objective: 18F-Flutemetamol SUVR was used to differentiate 1) mild cognitive impairment (MCI) from Alzheimer’s disease (AD), and 2) MCI from other non-AD dementias (OD). Methods: 109 patients consecutively recruited from a University memory clinic underwent clinical evaluation, neuropsychological test, MRI and 18F-Flutemetamol PET-CT. The diagnosis was made by consensus of a panel consisting of 1 neuroradiologist and 2 geriatricians. The final cohort included 13 subjective cognitive decline (SCD), 22 AD, 39 MCI, and 35 OD. Quantitative analysis of 16 region-of-interests made by Cortex ID software (GE Healthcare). Results: The global mean 18F-Flutemetamol SUVR in SCD, MCI, AD, and OD were 0.50 (SD-0.08), 0.53 (SD-0.16), 0.76 (SD-0.10), and 0.56 (SD-0.16), respectively, with SUVR in SCD and MCI and OD being significantly lower than AD. Aβ binding in SCD, MCI, and OD was heterogeneous, being 23%, 38.5%, and 42.9% respectively, as compared to 100% amyloid positivity in AD. Using global SUVR, ROC analysis showed AUC of 0.868 and 0.588 in differentiating MCI from AD and MCI from OD respectively. Conclusion: 18F-Flutemetamol SUVR differentiated MCI from AD with high efficacy (high negative predictive value), but much lower efficacy from OD. The major benefit of the test was to differentiate cognitively impaired patients (either SCD, MCI, or OD) without AD-related-amyloid-pathology from AD in the clinical setting, which was under-emphasized in the current guidelines proposed by Amyloid Imaging Task Force.


2021 ◽  
Vol 11 (2) ◽  
pp. 215
Author(s):  
Donovan A. McGrowder ◽  
Fabian Miller ◽  
Kurt Vaz ◽  
Chukwuemeka Nwokocha ◽  
Cameil Wilson-Clarke ◽  
...  

Alzheimer’s disease is a progressive, clinically heterogeneous, and particularly complex neurodegenerative disease characterized by a decline in cognition. Over the last two decades, there has been significant growth in the investigation of cerebrospinal fluid (CSF) biomarkers for Alzheimer’s disease. This review presents current evidence from many clinical neurochemical studies, with findings that attest to the efficacy of existing core CSF biomarkers such as total tau, phosphorylated tau, and amyloid-β (Aβ42), which diagnose Alzheimer’s disease in the early and dementia stages of the disorder. The heterogeneity of the pathophysiology of the late-onset disease warrants the growth of the Alzheimer’s disease CSF biomarker toolbox; more biomarkers showing other aspects of the disease mechanism are needed. This review focuses on new biomarkers that track Alzheimer’s disease pathology, such as those that assess neuronal injury (VILIP-1 and neurofilament light), neuroinflammation (sTREM2, YKL-40, osteopontin, GFAP, progranulin, and MCP-1), synaptic dysfunction (SNAP-25 and GAP-43), vascular dysregulation (hFABP), as well as CSF α-synuclein levels and TDP-43 pathology. Some of these biomarkers are promising candidates as they are specific and predict future rates of cognitive decline. Findings from the combinations of subclasses of new Alzheimer’s disease biomarkers that improve their diagnostic efficacy in detecting associated pathological changes are also presented.


2015 ◽  
Vol 45 (2) ◽  
pp. 527-542 ◽  
Author(s):  
D. Richard Lachno ◽  
Barbara A. Evert ◽  
Kaia Maloney ◽  
Brian A. Willis ◽  
Jayne A. Talbot ◽  
...  

2021 ◽  
pp. 1-12
Author(s):  
Heng Zhang ◽  
Diyang Lyu ◽  
Jianping Jia ◽  

Background: Synaptic degeneration has been suggested as an early pathological event that strongly correlates with severity of dementia in Alzheimer’s disease (AD). However, changes in longitudinal cerebrospinal fluid (CSF) growth-associated protein 43 (GAP-43) as a synaptic biomarker in the AD continuum remain unclear. Objective: To assess the trajectory of CSF GAP-43 with AD progression and its association with other AD hallmarks. Methods: CSF GAP-43 was analyzed in 788 participants from the Alzheimer’s Disease Neuroimaging Initiative (ADNI), including 246 cognitively normal (CN) individuals, 415 individuals with mild cognitive impairment (MCI), and 127 with AD dementia based on cognitive assessments. The associations between a multimodal classification scheme with amyloid-β (Aβ), tau, and neurodegeneration, and changes in CSF GAP-43 over time were also analyzed. Results: CSF GAP-43 levels were increased at baseline in MCI and dementia patients, and increased significantly over time in the preclinical (Aβ-positive CN), prodromal (Aβ-positive MCI), and dementia (Aβ-positive dementia) stages of AD. Higher levels of CSF GAP-43 were also associated with higher CSF phosphorylated tau (p-tau) and total tau (t-tau), cerebral amyloid deposition and hypometabolism on positron emission tomography, the hippocampus and middle temporal atrophy, and cognitive performance deterioration at baseline and follow-up. Furthermore, CSF GAP-43 may assist in effectively predicting the probability of dementia onset at 2- or 4-year follow-up. Conclusion: CSF GAP-43 can be used as a potential biomarker associated with synaptic degeneration in subjects with AD; it may also be useful for tracking the disease progression and for monitoring the effects of clinical trials.


2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Tobias Gustavsson ◽  
Stina Syvänen ◽  
Paul O’Callaghan ◽  
Dag Sehlin

Abstract Background Alzheimer’s disease (AD) immunotherapy with antibodies targeting amyloid-β (Aβ) has been extensively explored in clinical trials. The aim of this study was to study the long-term brain distribution of two radiolabeled monoclonal Aβ antibody variants – RmAb158, the recombinant murine version of BAN2401, which has recently demonstrated amyloid removal and reduced cognitive decline in AD patients, and the bispecific RmAb158-scFv8D3, which has been engineered for enhanced brain uptake via transferrin receptor-mediated transcytosis. Methods A single intravenous injection of iodine-125 (125I)-labeled RmAb158-scFv8D3 or RmAb158 was administered to AD transgenic mice (tg-ArcSwe). In vivo single-photon emission computed tomography was used to investigate brain retention and intrabrain distribution of the antibodies over a period of 4 weeks. Activity in blood and brain tissue was measured ex vivo and autoradiography was performed in combination with Aβ and CD31 immunostaining to investigate the intrabrain distribution of the antibodies and their interactions with Aβ. Results Despite faster blood clearance, [125I]RmAb158-scFv8D3 displayed higher brain exposure than [125I]RmAb158 throughout the study. The brain distribution of [125I]RmAb158-scFv8D3 was more uniform and coincided with parenchymal Aβ pathology, while [125I]RmAb158 displayed a more scattered distribution pattern and accumulated in central parts of the brain at later times. Ex vivo autoradiography indicated greater vascular escape and parenchymal Aβ interactions for [125I]RmAb158-scFv8D3, whereas [125I]RmAb158 displayed retention and Aβ interactions in lateral ventricles. Conclusions The high brain uptake and uniform intrabrain distribution of RmAb158-scFv8D3 highlight the benefits of receptor-mediated transcytosis for antibody-based brain imaging. Moreover, it suggests that the alternative transport route of the bispecific antibody contributes to improved efficacy of brain-directed immunotherapy.


2010 ◽  
Vol 21 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Tokuhei Ikeda ◽  
Kenjiro Ono ◽  
David Elashoff ◽  
Margaret M. Condron ◽  
Moeko Noguchi-Shinohara ◽  
...  

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