| 11. |
- Andreasson, Ulf, 1968, et al.
(författare)
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Aspects of beta-amyloid as a biomarker for Alzheimer's disease
- 2007
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Ingår i: Biomarkers in Medicine. - : Future Medicine Ltd. - 1752-0363 .- 1752-0371. ; 1:1, s. 59-78
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Forskningsöversikt (refereegranskat)abstract
- Alzheimer’s disease is an age-related neurodegenerative disorder that results in progressive cognitive impairment and death. The accumulation of β-amyloid (Aβ) in specific brain regions is believed by many to represent the earliest event in the pathogenesis of the disease. Here, we review the key aspects of Aβ as a biomarker for Alzheimer’s disease, including the pathogenicity of Aβ, the possible biological functions of its precursor protein, the Aβ metabolism and homeostasis, the diagnostic performance of different Aβ assays in different settings and the potential usefulness of Aβ as a surrogate marker for treatment efficacy in clinical trials of novel Aβ-targeting drugs against Alzheimer’s disease.
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| 12. |
- Andreasson, Ulf, 1968, et al.
(författare)
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Assessing the commutability of candidate reference materials for the harmonization of neurofilament light measurements in blood
- 2023
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1434-6621 .- 1437-4331. ; 61:7, s. 1245-1254
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Neurofilament light chain (NfL) concentration in blood is a biomarker of neuro-axonal injury in the nervous system and there now exist several assays with high enough sensitivity to measure NfL in serum and plasma. There is a need for harmonization with the goal of creating a certified reference material (CRM) for NfL and an early step in such an effort is to determine the best matrix for the CRM. This is done in a commutability study and here the results of the first one for NfL in blood is presented.Methods Forty paired individual serum and plasma samples were analyzed for NfL on four different analytical platforms. Neat and differently spiked serum and plasma were evaluated for their suitability as a CRM using the difference in bias approach.Results The correlation between the different platforms with regards to measured NfL concentrations were very high (Spearman's rho >= 0.96). Samples spiked with cerebrospinal fluid (CSF) showed higher commutability compared to samples spiked with recombinant human NfL protein and serum seems to be a better choice than plasma as the matrix for a CRM.Conclusions The results from this first commutability study on NfL in serum/plasma showed that it is feasible to create a CRM for NfL in blood and that spiking should be done using CSF rather than with recombinant human NfL protein.
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| 13. |
- Andreasson, Ulf, 1968, et al.
(författare)
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Commutability of the certified reference materials for the standardization of beta-amyloid 1-42 assay in human cerebrospinal fluid: lessons for tau and beta-amyloid 1-40 measurements
- 2018
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1434-6621 .- 1437-4331. ; 56:12, s. 2058-2066
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Tidskriftsartikel (refereegranskat)abstract
- Background: The core Alzheimer's disease cerebrospinal fluid (CSF) biomarkers total tau (T-tau), phosphorylated tau (P-tau), beta-amyloid 1-42 (A beta 42) and beta-amyloid 1-40 (A beta 40) are increasing in importance and are now part of the research criteria for the diagnosis of the disease. The main aim of this study is to evaluate whether a set of certified reference materials (CRMs) are commutable for A beta 42 and to serve as a feasibility study for the other markers. This property is a prerequisite for the establishment of CRMs which will then be used by manufacturers to calibrate their assays against. Once the preanalytical factors have been standardized and proper selection criteria are available for subject cohorts this harmonization between methods will allow for universal cut-offs to be determined. Methods: Thirty-four individual CSF samples and three different CRMs where analyzed for T-tau, P-tau, A beta 42 and A beta 40, using up to seven different commercially available methods. For A beta 40 and A beta 42 a mass spectrometry-based procedure was also employed. Results: There were strong pairwise correlations between the different methods (Spearman's p>0.92) for all investigated analytes and the CRMs were not distinguishable from the individual samples. Conclusions: This study shows that the CRMs are commutable for the different assays for A beta 42. For the other analytes the results show that it would be feasible to also produce CRMs for these. However, additional studies are needed as the concentration interval for the CRMs were selected based on A beta 42 concentrations only and did in general not cover satisfactory large concentration intervals for the other analytes.
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| 14. |
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| 15. |
- Andreasson, Ulf, 1968, et al.
(författare)
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Method and Clinical Validation of Biomarkers for Neurodegenerative Diseases
- 2021
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Ingår i: Cerebrospinal Fluid Biomarkers. Neuromethods, vol 168. Teunissen C.E., Zetterberg H. (eds). - New York, NY : Springer. - 0893-2336. - 9781071613184 ; , s. 163-173
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In the Merriam-Webster dictionary, one definition of the word valid is “well-grounded or justifiable: being at once relevant and meaningful.” Validation is then the process of determining the degree of validity. From this broad definition, it follows that validations can be made in many different fields with quite different implications. When talking about validation, it is therefore important to specify the subject under scrutiny and in this chapter the focus will be on validation of biomarkers. © 2021, Springer Science+Business Media, LLC, part of Springer Nature.
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| 16. |
- Andreasson, Ulf, 1968, et al.
(författare)
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Multiplexing and multivariate analysis in neurodegeneration.
- 2012
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Ingår i: Methods (San Diego, Calif.). - : Elsevier BV. - 1095-9130 .- 1046-2023. ; 56:4, s. 464-70
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Tidskriftsartikel (refereegranskat)abstract
- Limited sample volume is often an obstacle in clinical research and one way to circumvent this is to use multiplex techniques where several different analytes are simultaneously measured. There is a multitude of different platforms that can be used for multiplexing and their uniqueness and similarities will be described. Multivariate analysis is a powerful tool for extracting information from multiplex data. An introduction to one such algorithm is presented followed by examples from the literature, in the field of neurodegeneration, where multiplex and multivariate methods have been used.
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| 17. |
- Andreasson, Ulf, 1968, et al.
(författare)
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Update on ultrasensitive technologies to facilitate research on blood biomarkers for central nervous system disorders.
- 2016
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Ingår i: Alzheimer's & dementia (Amsterdam, Netherlands). - : Wiley. - 2352-8729. ; 3, s. 98-102
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Tidskriftsartikel (refereegranskat)abstract
- Most research on fluid biomarkers for central nervous system (CNS) disorders has so far been performed using cerebrospinal fluid (CSF) as the biomarker source. CSF has the advantage of being closer to the brain than serum or plasma with a relative enrichment of CNS-specific proteins that are present at very low concentrations in the blood and thus difficult to reliably quantify using standard immunochemical technologies. Recent technical breakthroughs in the field of ultrasensitive assays have started to change this. Here, we review the most established ultrasensitive quantitative technologies that are currently available to general biomarker laboratories and discuss their use in research on biomarkers for CNS disorders.
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| 18. |
- Arvidsson Rådestig, Maya, et al.
(författare)
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Cerebrospinal fluid biomarkers of axonal and synaptic degeneration in a population-based sample
- 2023
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Ingår i: Alzheimers Research & Therapy. - : Springer Science and Business Media LLC. - 1758-9193. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundNeurofilament light (NfL) and neurogranin (Ng) are promising candidate AD biomarkers, reflecting axonal and synaptic damage, respectively. Since there is a need to understand the synaptic and axonal damage in preclinical Alzheimer's disease (AD), we aimed to determine the cerebrospinal fluid (CSF) levels of NfL and Ng in cognitively unimpaired elderly from the Gothenburg H70 Birth Cohort Studies classified according to the amyloid/tau/neurodegeneration (A/T/N) system.MethodsThe sample consisted of 258 cognitively unimpaired older adults (age 70, 129 women and 129 men) from the Gothenburg Birth Cohort Studies. We compared CSF NfL and Ng concentrations in A/T/N groups using Student's T-test and ANCOVA.ResultsCSF NfL concentration was higher in the A-T-N+ group (p=0.001) and the A-T+N+ group (p=0.006) compared with A-T-N-. CSF Ng concentration was higher in the A-T-N+, A-T+N+, A+T-N+, and A+T+N+ groups (p<0.0001) compared with A-T-N-. We found no difference in NfL or Ng concentration in A+ compared with A- (disregarding T- and N- status), whereas those with N+ had higher concentrations of NfL and Ng compared with N- (p<0.0001) (disregarding A- and T- status).ConclusionsCSF NfL and Ng concentrations are increased in cognitively normal older adults with biomarker evidence of tau pathology and neurodegeneration.
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| 19. |
- Augutis, Kristin, et al.
(författare)
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Cerebrospinal fluid biomarkers of β-amyloid metabolism in multiple sclerosis.
- 2013
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Ingår i: Multiple sclerosis (Houndmills, Basingstoke, England). - : SAGE Publications. - 1477-0970 .- 1352-4585. ; 19:5, s. 543-52
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid precursor protein (APP) and amyloid β (Aβ) peptides are intensely studied in neuroscience and their cerebrospinal fluid (CSF) measurements may be used to track the metabolic pathways of APP in vivo. Reduced CSF levels of Aβ and soluble APP (sAPP) fragments are reported in inflammatory diseases, including multiple sclerosis (MS); but in MS, the precise pathway of APP metabolism and whether it can be affected by disease-modifying treatments remains unclear.
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| 20. |
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