| 31. |
- Bhattacharjee, Payel, 1984, et al.
(författare)
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Mass Spectrometric Analysis of Lewy Body-Enriched alpha-Synuclein in Parkinson's Disease
- 2019
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 18:5, s. 2109-2120
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Tidskriftsartikel (refereegranskat)abstract
- Parkinson's disease (PD) is characterized by intraneuronal inclusions of aggregated alpha-synuclein protein (so-called Lewy bodies) in distinct brain regions. Multiple posttranslational modifications may affect the structure and function of alpha-synuclein. Mass spectrometry-based analysis may be useful for the characterization and quantitation of alpha-synuclein forms, but has proven challenging, mainly due to the insolubility of Lewy bodies in aqueous buffer. In the present study, we developed a novel method by combining differential solubilization with immunoprecipitation and targeted proteomics using liquid chromatography and tandem mass spectrometry. Brain tissue homogenization and sample preparation were modified to facilitate analysis of soluble, detergent-soluble, and detergent-insoluble protein fractions (Lewy body-enriched). The method was used to compare alpha-synuclein forms from cingulate cortex (affected) and occipital cortex (unaffected) in two study sets of PD patients and controls. We identified similar to 20 modified alpha-synuclein variants, including species with N-terminal acetylation and C-terminal truncations at amino acids 103 and 119. The levels of alpha-synuclein forms Ac-alpha-syn(1-6), alpha-syn(13-21), alpha-syn(35-43), alpha-syn(46-58), alpha-syn(61-80), and alpha-syn(81-96) except alpha-syn(103-119) were significantly increased in PD cingulate region compared to controls in the Lewy body-enriched alpha-synuclein fraction. In the soluble fraction, only Ac-alpha-syn(1-6) was significantly increased in PD compared to controls. None of the detected alpha-synuclein variants were Lewy body-specific, but acetylated forms should be examined further as potential biomarkers for abnormal alpha-synuclein accumulation.
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| 32. |
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| 33. |
- Bjerke, Maria, 1977, et al.
(författare)
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Assessing the commutability of reference material formats for the harmonization of amyloid beta measurements.
- 2016
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Ingår i: Clinical chemistry and laboratory medicine : CCLM / FESCC. - : Walter de Gruyter GmbH. - 1437-4331 .- 1434-6621. ; 54:7, s. 1177-91
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The cerebrospinal fluid (CSF) amyloid-β (Aβ42) peptide is an important biomarker for Alzheimer's disease (AD). Variability in measured Aβ42 concentrations at different laboratories may be overcome by standardization and establishing traceability to a reference system. Candidate certified reference materials (CRMs) are validated herein for this purpose. METHODS: Commutability of 16 candidate CRM formats was assessed across five CSF Aβ42 immunoassays and one mass spectrometry (MS) method in a set of 48 individual clinical CSF samples. Promising candidate CRM formats (neat CSF and CSF spiked with Aβ42) were identified and subjected to validation across eight (Elecsys, EUROIMMUN, IBL, INNO-BIA AlzBio3, INNOTEST, MSD, Simoa, and Saladax) immunoassays and the MS method in 32 individual CSF samples. Commutability was evaluated by Passing-Bablok regression and the candidate CRM termed commutable when found within the prediction interval (PI). The relative distance to the regression line was assessed. RESULTS: The neat CSF candidate CRM format was commutable for almost all method comparisons, except for the Simoa/MSD, Simoa/MS and MS/IBL where it was found just outside the 95% PI. However, the neat CSF was found within 5% relative distance to the regression line for MS/IBL, between 5% and 10% for Simoa/MS and between 10% and 15% for Simoa/MSD comparisons. CONCLUSIONS: The neat CSF candidate CRM format was commutable for 33 of 36 method comparisons, only one comparison more than expected given the 95% PI acceptance limit. We conclude that the neat CSF candidate CRM can be used for value assignment of the kit calibrators for the different Aβ42 methods.
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| 34. |
- Bjerke, Maria, 1977, et al.
(författare)
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Cerebrospinal Fluid Fatty Acid-Binding Protein 3 is Related to Dementia Development in a Population-Based Sample of Older Adult Women Followed for 8 Years.
- 2016
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Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908. ; 49:3, s. 733-741
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Increased fatty acid-binding protein 3 (FABP-3) levels have been reported in neurodegenerative diseases, including Alzheimer's disease (AD). Cerebrospinal fluid (CSF) FABP-3 has therefore been proposed as a putative marker for dementia. Population-based studies examining whether CSF FABP-3 predicts later development of dementia are lacking. OBJECTIVE: The aim of this study was to examine CSF levels of FABP-3 in relation to later development of dementia in elderly women and in relation to Aβ42, T-tau, P-tau181, and CSF: serum albumin ratio. METHODS: 86 non-demented women aged 70-84 years who participated in the Prospective Population Study of Women in Gothenburg, Sweden took part in a lumbar puncture in 1992-93. CSF-FABP-3, Aβ42, T-tau, P-tau181, and the CSF: serum albumin ratio were measured at baseline. Participants were examined with a neuropsychiatric exam at baseline and at follow-up in 2000. Dementia was diagnosed in accordance with DSM-III-R criteria. RESULTS: Between 1992 and 2000, 8 women developed dementia (4 AD, 3 vascular dementia, 1 mixed vascular dementia and AD). Higher levels of CSF-FABP-3 at baseline were related to development of dementia (OR 1.36 CI [1.05-1.76] p=0.022) and the subtype AD (OR 1.38 CI [1.06-1.82), p=0.019) during follow-up. FABP-3 correlated with CSF T-tau (r=0.88, p< 0.001), P-tau181 (r=0.619, p< 0.001), and CSF:serum albumin ratio (r=0.233, p=0.031), but not with Aβ42 (r=-0.08, p=0.444)Conclusion: CSF FABP-3 may be an early marker for later development of dementia, probably related to neuronal degeneration, but independent of Aβ metabolism.
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| 35. |
- Blennow, Kaj, 1958
(författare)
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A Review of Fluid Biomarkers for Alzheimer's Disease: Moving from CSF to Blood.
- 2017
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Ingår i: Neurology and therapy. - : Springer Science and Business Media LLC. - 2193-8253 .- 2193-6536. ; 6:Suppl 1, s. 15-24
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Tidskriftsartikel (refereegranskat)abstract
- A set of core cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease (AD) includes total tau (T-tau), phosphorylated tau (P-tau) and β-amyloid 42 (Aβ42). These biomarkers reflect some of the key aspects of AD pathophysiology, including neuronal degeneration, tau phosphorylation with tangle formation, and Aβ aggregation with deposition of the peptide into plaques. The core AD CSF biomarkers have been validated clinically in numerous studies, and found to have a very high diagnostic performance to identify AD, both in the dementia and in the mild cognitive impairment stages of the disease. CSF Aβ42 has also been found to show very high concordance with amyloid PET to identify brain amyloid deposition. The synaptic protein neurogranin is a novel candidate CSF biomarker for AD and prodromal AD. High CSF neurogranin predicts future cognitive decline and seems to be more specific for AD than, for example, T-tau. Importantly, technical developments have given ultrasensitive measurement techniques that allow measurement of brain-specific proteins such as tau and neurofilament light (NFL) in blood samples. Both plasma tau and NFL are increased in AD, and a recent study showed that plasma NFL has a diagnostic performance comparable to the core AD CSF biomarkers, and predicted future cognitive decline. Future large longitudinal clinical studies are warranted to determine the potential for plasma tau and NFL to serve as first-in-line screening tools for neurodegeneration in primary care.
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| 36. |
- Blennow, Kaj, 1958, et al.
(författare)
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Amyloid biomarkers in Alzheimer's disease.
- 2015
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Ingår i: Trends in pharmacological sciences. - : Elsevier BV. - 1873-3735 .- 0165-6147. ; 36:5, s. 297-309
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Tidskriftsartikel (refereegranskat)abstract
- Aggregation of amyloid-β (Aβ) into oligomers, fibrils, and plaques is central in the molecular pathogenesis of Alzheimer's disease (AD), and is the main focus of AD drug development. Biomarkers to monitor Aβ metabolism and aggregation directly in patients are important for further detailed study of the involvement of Aβ in disease pathogenesis and to monitor the biochemical effect of drugs targeting Aβ in clinical trials. Furthermore, if anti-Aβ disease-modifying drugs prove to be effective clinically, amyloid biomarkers will be of special value in the clinic to identify patients with brain amyloid deposition at risk for progression to AD dementia, to enable initiation of treatment before neurodegeneration is too severe, and to monitor drug effects on Aβ metabolism or pathology to guide dosage. Two types of amyloid biomarker have been developed: Aβ-binding ligands for use in positron emission tomography (PET) and assays to measure Aβ42 in cerebrospinal fluid (CSF). In this review, we present the rationales behind these biomarkers and compare their ability to measure Aβ plaque load in the brain. We also review possible shortcomings and the need of standardization of both biomarkers, as well as their implementation in the clinic.
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| 37. |
- Blennow, Kaj, 1958, et al.
(författare)
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Biomarkers for Alzheimer disease - current status and prospects for the future.
- 2018
-
Ingår i: Journal of internal medicine. - : Wiley. - 1365-2796 .- 0954-6820. ; 284:6, s. 643-663
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Tidskriftsartikel (refereegranskat)abstract
- Accumulating data from clinical research support that the core Alzheimer disease (AD) cerebrospinal fluid (CSF) biomarkers amyloid β (Aβ42), total-tau (T-tau), and phosphorylated tau (P-tau) reflect key elements of AD pathophysiology. Importantly, a large number of clinical studies very consistently show that these biomarkers contribute with diagnostically relevant information, also in the early disease stages. Recent technical developments have made it possible to measure these biomarkers using fully automated assays with high precision and stability. Standardization efforts have given Certified Reference Materials for CSF Aβ42, with the aim to harmonize results between assay formats that would allow for uniform global reference limits and cut-off values. These encouraging developments have led to that the core AD CSF biomarkers have a central position in the novel diagnostic criteria for the disease and in the recent National Institute on Aging and Alzheimer's Association biological definition of AD. Taken together, this progress will likely serve as the basis for a more general introduction of these diagnostic tests in clinical routine practice. However, the heterogeneity of pathology in late-onset AD calls for an expansion of the AD CSF biomarker toolbox with additional biomarkers reflecting additional aspects of AD pathophysiology. One promising candidate is the synaptic protein neurogranin that seems specific for AD and predicts future rate of cognitive deterioration. Further, recent studies brings hope for easily accessible and cost effective screening tools in the early diagnostic evaluation of patients with cognitive problems (and suspected AD) in primary care. In this respect, technical developments with ultrasensitive immunoassays and novel mass spectrometry techniques give promise of biomarkers to monitor brain amyloidosis (the Aβ42/40, or APP669-711/Aβ42 ratios), and neurodegeneration (tau and neurofilament light proteins) in plasma samples, but future studies are warranted to validate these promising results further. This article is protected by copyright. All rights reserved.
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| 38. |
- Blennow, Kaj, 1958, et al.
(författare)
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Cerebrospinal Fluid Biomarkers in Alzheimer's and Parkinson's Diseases-From Pathophysiology to Clinical Practice
- 2016
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Ingår i: Movement Disorders. - : Wiley. - 0885-3185. ; 31:6, s. 836-847
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Tidskriftsartikel (refereegranskat)abstract
- This review provides an update on the role, development, and validation of CSF biomarkers in the diagnosis and prognosis of Alzheimer's disease and PD. Some recent developments on novel biomarkers are also discussed. We also give an overview of methodological/technical factors still hampering the global validation and standardization of CSF Alzheimer's disease and PD biomarkers. CSF biomarkers have the potential to improve the diagnostic accuracy at the early stages not only for Alzheimer's disease but also for PD. This step is essential in view of the availability of disease-modifying treatments. Our vision for the future is that analyzing biomarker panels on a minute amount of CSF could provide important information on the whole spectrum of the molecular pathogenic events characterizing these neurodegenerative disorders. CSF core biomarkers have already been included in the diagnostic criteria for Alzheimer's disease, and they are also under consideration as tools to monitor the effects of disease-modifying drugs. With respect to PD, their potential for improving diagnostic accuracy in early diagnosis is under intense research, resembling the same path followed for Alzheimer's disease.
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| 39. |
- Blennow, Kaj, 1958, et al.
(författare)
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Clinical utility of cerebrospinal fluid biomarkers in the diagnosis of early Alzheimer's disease.
- 2015
-
Ingår i: Alzheimer's & dementia : the journal of the Alzheimer's Association. - : Wiley. - 1552-5279. ; 11:1, s. 58-69
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Tidskriftsartikel (refereegranskat)abstract
- Several potential disease-modifying drugs for Alzheimer's disease (AD) have failed to show any effect on disease progression in clinical trials, conceivably because the AD subjects are already too advanced to derive clinical benefit from treatment and because diagnosis based on clinical criteria alone introduces a high misdiagnosis rate. Thus, well-validated biomarkers for early detection and accurate diagnosis are crucial. Low cerebrospinal fluid (CSF) concentrations of the amyloid-β (Aβ1-42) peptide, in combination with high total tau and phosphorylated tau, are sensitive and specific biomarkers highly predictive of progression to AD dementia in patients with mild cognitive impairment. However, interlaboratory variations in the results seen with currently available immunoassays are of concern. Recent worldwide standardization efforts and quality control programs include standard operating procedures for both preanalytical (e.g., lumbar puncture and sample handling) and analytical (e.g., preparation of calibration curve) procedures. Efforts are also ongoing to develop highly reproducible assays on fully automated instruments. These global standardization and harmonization measures will provide the basis for the generalized international application of CSF biomarkers for both clinical trials and routine clinical diagnosis of AD.
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| 40. |
- Blennow, Kaj, 1958, et al.
(författare)
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- CSF neurogranin as a neuronal damage marker in CJD: A comparative study with AD
- 2019
-
Ingår i: Journal of Neurology, Neurosurgery and Psychiatry. - : BMJ. - 0022-3050 .- 1468-330X. ; 90:8
-
Tidskriftsartikel (refereegranskat)abstract
- - Objective: To investigate whether cerebrospinal fluid (CSF) neurogranin concentrations are altered in sporadic Creutzfeldt-Jakob disease (CJD), comparatively with Alzheimer's disease (AD), and associated with neuronal degeneration in brain tissue. Methods: CSF neurogranin, total tau, neurofilament light (NFL) and 14-3-3 protein were measured in neurological controls (NCs, n=64), AD (n=46) and CJD (n=81). The accuracy of neurogranin discriminating the three diagnostic groups was evaluated. Correlations between neurogranin and neurodegeneration biomarkers, demographic, genetic and clinical data were assessed. Additionally, neurogranin expression in postmortem brain tissue was studied. Results: Compared with NC, CSF neurogranin concentrations were increased in CJD (4.75 times of NC; p<0.001, area under curve (AUC), 0.96 (95% CI 0.93 to 0.99) and AD (1.94 times of NC; p<0.01, AUC 0.73, 95% CI 0.62 to 0.82), and were able to differentiate CJD from AD (p<0.001, AUC 0.85, 95% CI 0.78 to 0.92). CSF tau was increased in CJD (41 times of NC) and in AD (3.1 times of NC), both at p<0.001. In CJD, neurogranin positively correlated with tau (r=0.55, p<0.001) and was higher in 14-3-3-positivity (p<0.05), but showed no association with NFL (r=0.08, p=0.46). CJD-MM1/MV1 cases displayed higher neurogranin levels than VV2 cases. Neurogranin was increased at early CJD disease stages and was a good prognostic marker of survival time in CJD. In brain tissue, neurogranin was detected in the cytoplasm, membrane and postsynaptic density fractions of neurons, with reduced levels in AD, and more significantly in CJD, where they correlated with synaptic and axonal markers. Conclusions: Neurogranin is a new biomarker of prion pathogenesis with diagnostic and prognostic abilities, which reflects the degree of neuronal damage in brain tissue in a CJD subtype manner. © Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.
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