| 1. |
- Andersson, Christin, et al.
(author)
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Increasing CSF phospho-tau levels during cognitive decline and progression to dementia
- 2008
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In: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 29:10, s. 1466-1473
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Journal article (peer-reviewed)abstract
- BACKGROUND: Little is known about longitudinal changes of cerebrospinal fluid (CSF) biomarkers during cognitive decline in neurodegenerative disease progression. OBJECTIVE: To investigate longitudinal changes in CSF biomarkers--total-tau (T-tau), phospho-tau (P-tau) and beta-amyloid (Abeta42)--during cognitive decline. METHODS: Forty memory clinic patients (47.5% females), aged 61.3+/-7.6 (S.D.) years, non-demented at baseline, underwent lumbar puncture and neuropsychological testing at two occasions. Baseline mean MMSE-score was 28.3+/-1.8. Patients were divided into three groups based on baseline memory functioning; severely impaired (SIM), moderately impaired (MIM) and no impairment (NIM). RESULTS: There was a significant increase in P-tau in the SIM-group during follow-up, while P-tau in MIM and NIM did not change. Eighty-three percent of the SIM-patients converted to dementia (80% AD), while most MIM- and NIM-patients remained non-demented. T-tau- and Abeta42-levels did not change in any of the memory groups during follow-up. CONCLUSION: Increasing P-tau levels during cognitive decline and conversion to dementia suggest that P-tau may be useful as a longitudinal marker of the neurodegenerative process.
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| 2. |
- Andersson, Malin E, 1978, et al.
(author)
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Kinesin gene variability may affect tau phosphorylation in early Alzheimer's disease.
- 2007
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In: International journal of molecular medicine. - 1107-3756 .- 1791-244X. ; 20:2, s. 233-9
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Journal article (peer-reviewed)abstract
- Kinesin is a microtubule-associated motor protein that transports Alzheimer-associated amyloid precursor protein (APP) in neurons. In animal models, impaired kinesin-mediated APP transport seems to enhance formation of the neurotoxic 42 amino acid fragment of beta-amyloid (A beta 42). In man, one study suggests that a polymorphism (rs8702, 56,836G>C) in the kinesin light chain 1 gene (KNS2) may affect the risk of Alzheimer's disease (AD). To further assess KNS2 as a susceptibility gene for AD we analyzed 802 patients with sporadic AD and 286 controls, 134 longitudinally followed patients with mild cognitive impairment (MCI) and 39 cognitively stable controls for the rs8702 polymorphism. The rs8702 polymorphism did not influence risk of AD (p=0.46). However, rs8702 interacted with APOE epsilon 4 carrier status in AD (p=0.006) and influenced cerebrospinal fluid levels of hyperphosphorylated tau in MCI patients who converted to AD during follow-up (p=0.018). These findings support earlier indications that genetic variability in the KNS2 gene may play a role during early stages of AD pathogenesis.
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| 3. |
- Andreasen, Niels, et al.
(author)
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Amyloid-related biomarkers for Alzheimer's disease.
- 2008
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In: Current medicinal chemistry. - : Bentham Science Publishers Ltd.. - 0929-8673. ; 15:8, s. 766-71
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Research review (peer-reviewed)abstract
- Alzheimer's disease (AD) is an age-related disorder that causes brain damage resulting in progressive cognitive impairment and death. Three decades of progress have given us a detailed understanding of the underlying molecular mechanisms. Over the past 10 years, this knowledge has translated into a range of targets for therapy, the most promising of which is amyloid beta (Abeta). An imbalance between the production and clearance of Abeta is thought by many to represent the earliest event in the pathogenesis of AD. Abeta is known to be subject to oligomerisation, a process that increases its synaptotoxicity. The oligomers may aggregate further to proto-fibrils and fibrils, eventually forming senile plaques, the neuropathological hallmark of AD. In this article we review the key aspects of Abeta as a biomarker for AD, including its pathogenicity, the diagnostic performance of different Abeta assays in different settings, and the potential usefulness of Abeta as a surrogate marker for treatment efficacy in clinical trials of novel Abeta-targeting drugs.
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| 4. |
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| 5. |
- Blennow, Kaj, 1958, et al.
(author)
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Longitudinal stability of CSF biomarkers in Alzheimer's disease
- 2007
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In: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 419:1, s. 18-22
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Journal article (peer-reviewed)abstract
- Biomarker levels in cerebrospinal fluid (CSF) may serve as surrogate markers for treatment efficacy in clinical trials of disease-modifying drugs against Alzheimer's disease (AD). A prerequisite, however, is that the marker is sufficiently stable over time in individual patients. Here, we tested the stability of the three established CSF biomarkers for AD, total tau (T-tau), tau phosphorylated at threonine 181 (P-tau181) and the 42 amino acid isoform of β-amyloid (Aβ42), over 6 months in a cohort of AD patients on stable treatment with acetylcholinesterase (AChE) inhibitors. Fifty-three patients completed the study, 29 men and 24 women, mean age (±S.D.) 76.1 ± 7.9 years. Mean levels of CSF biomarkers were very stable between baseline and endpoint, with coefficients of variation (CVs) of 4.4–6.1%. Intra-individual biomarker levels at baseline and endpoint were also highly correlated with Pearson r-values above 0.95 (p < 0.0001), for all three markers. We conclude that T-tau, P-tau and Aβ42 concentrations in CSF are remarkably stable over a 6-month period in individual AD patients. This suggest that these biomarkers may have a potential to identify and monitor very minor biochemical changes induced by treatment, and thus support their possible usefulness as surrogate markers in clinical trials with drug candidates with disease-modifying potential, such as secretase inhibitors, Aβ immunotherapy and tau phosphorylation inhibitors.
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| 6. |
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| 7. |
- Blomqvist, Mia E-L, et al.
(author)
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Towards compendia of negative genetic association studies: an example for Alzheimer disease.
- 2006
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In: Human genetics. - : Springer Science and Business Media LLC. - 0340-6717 .- 1432-1203. ; 119:1-2, s. 29-37
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Journal article (peer-reviewed)abstract
- Most genetic sequence variants that contribute to variability in complex human traits will have small effects that are not readily detectable with population samples typically used in genetic association studies. A potentially valuable tool in the gene discovery process is meta-analysis of the accumulated published data, but in order to be valid these require a sample of studies representative of the true genetic effect and thus hypothetically should include some positive and an abundance of negative reports. A survey of the literature on association studies for Alzheimer disease (AD) from January 2004-April 2005, identified 138 studies, 86 of which reported positive findings other than for apolipoprotein E (APOE), strongly indicative of publication bias. We report here an analysis of 62 genetic markers, tested for association with AD risk as well as for possible effects upon quantitative indices of AD severity (mini-mental state examination scores, age-at-onset, and cerebrospinal fluid (CSF) beta-amyloid (Abeta) and CSF tau proteins). Within this set, only modest signals were present that, with the exception of APOE are easily lost when corrections for multiple hypotheses are applied. In isolation, results are thus broadly negative. Genes studied encompass both novel candidates as well as several recently claimed to be associated with AD (e.g. urokinase plasminogen activator (PLAU) and acetyl-coenzyme A acetyltransferase 1 (ACAT1)). By reporting these data we hope to encourage the publication of gene compendia to guide further studies and aid future meta-analyses aimed at resolving the involvement of genes in complex human traits.
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| 8. |
- Buchhave, Peder, et al.
(author)
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Longitudinal study of CSF biomarkers in patients with Alzheimer's disease.
- 2009
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In: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 16:Suppl 3, s. 337-337
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Journal article (peer-reviewed)abstract
- BACKGROUND: The CSF biomarkers tau and Abeta42 can identify patients with AD, even during the preclinical stages. However, previous studies on longitudinal changes of tau and Abeta42 in individual patients with AD and elderly controls report somewhat inconsistent results. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the levels of tau and Abeta42 at baseline and after 1 year in 100 patients with AD. In a second cohort of 45 AD patients we measured the CSF biomarkers at baseline and after 2 years. Moreover, in 34 healthy elderly controls the CSF biomarkers were followed for 4 years. The baseline levels of tau were increased with >60% in AD patients compared to controls (p<0.001), while baseline Abeta42 levels were decreased with >50% (p<0.001). In the AD group followed for 2 years, tau increased with 16% compared to the baseline levels (p<0.05). However, the levels of tau were stable over 4 years in the controls. The levels of Abeta42 did not change significantly over time in any of the groups. In the patients with AD, tau was moderately associated with worse cognitive performance already at baseline (p<0.05). CONCLUSIONS/SIGNIFICANCE: Tau and Abeta42 in CSF seem to reflect the underlying disease state in both early and late stages of AD. The slight increase in tau over time observed in the patients with AD is modest when compared to the relatively large difference in absolute tau levels between AD patients and controls. Therefore, these markers maintain their usefulness as state markers over time and might serve as surrogate markers for treatment efficacy in clinical trials.
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