| 1. |
- Parnetti, L, et al.
(författare)
-
Changes in CSF acetyl- and butyrylcholinesterase activity after long-term treatment with AChE inhibitors in Alzheimer's disease.
- 2011
-
Ingår i: Acta neurologica Scandinavica. - : Hindawi Limited. - 1600-0404 .- 0001-6314. ; 124:2, s. 122-129
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives - To measure cerebrospinal fluid (CSF) activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in patients with Alzheimer's disease (AD) participating in randomized clinical trials from three European centers, before and after long-term treatment with different AChE inhibitors (AChEIs). Materials and methods - Of the 144 patients included in the study, 104 were treated with donepezil, 15 with galantamine, 16 with rivastigmine, and nine with placebo. CSF AChE and BChE activities were measured at baseline and after 1-year treatment. Results - Donepezil and galantamine groups showed a significant increase in CSF AChE activity at follow-up, while no changes for BChE activity were observed; in donepezil group, a positive correlation between plasma concentration and AChE activity was documented. Conversely, in rivastigmine group, a decrease in CSF activity of both enzymes was observed. CSF AChE and BChE activities were not correlated with the clinical outcome in any group considered. CSF biomarkers did not show any change after treatment. Conclusions - AChEIs differently influence the activity of target enzymes in CSF independent of their pharmacodynamic effects.
|
|
| 2. |
- Alves, Guido, et al.
(författare)
-
Cerebrospinal fluid amyloid-β and phenotypic heterogeneity in de novo Parkinson's disease.
- 2013
-
Ingår i: Journal of neurology, neurosurgery, and psychiatry. - : BMJ. - 1468-330X .- 0022-3050. ; 84:5, s. 537-43
-
Tidskriftsartikel (refereegranskat)abstract
- In Parkinson's disease (PD), the motor presentation characterised by postural instability/gait difficulties (PIGD) heralds accelerated motor, functional and cognitive decline, as compared with the more benign tremor-dominant (TD) variant. This makes the PIGD complex an attractive target for the discovery of prognostic biomarkers in PD.
|
|
| 3. |
- Alves, Guido, et al.
(författare)
-
CSF amyloid-β and tau proteins, and cognitive performance, in early and untreated Parkinson's Disease: the Norwegian ParkWest study
- 2010
-
Ingår i: Journal of neurology, neurosurgery, and psychiatry. - : BMJ. - 1468-330X .- 0022-3050. ; 81:10, s. 1080-1086
-
Tidskriftsartikel (refereegranskat)abstract
- Background Alzheimer's disease (AD) pathology is found in a considerable portion of patients with Parkinson's disease (PD), particularly those with early dementia (PDD). Altered cerebrospinal fluid (CSF) levels of amyloid-beta (Abeta) and tau proteins have been found in PDD, with intermediate changes for Abeta42 in non-demented PD. The authors investigated whether AD-related CSF protein levels are altered and relate to neuropsychological performance in early, untreated PD. Methods CSF concentrations of Abeta42, Abeta40 and Abeta38 were measured by electrochemiluminiscene and levels of total tau (T-tau) and phosphorylated tau (P-tau) by ELISA in 109 newly diagnosed, unmedicated, non-demented, community-based PD patients who had undergone comprehensive neuropsychological testing, and were compared with those of 36 age-matched normal controls and 20 subjects with mild AD. Results PD patients displayed significant reductions in Abeta42 (19%; p=0.009), Abeta40 (15.5%; p=0.008) and Abeta38 (23%; p=0.004) but not T-tau (p=0.816) or P-tau (p=0.531) compared with controls. CSF Abeta42 reductions in PD were less marked than in AD (53%; p=0.002). Sequential regression analyses demonstrated significant associations between CSF levels of Abeta42 (beta=0.205; p=0.019), Abeta40 (beta=0.378; p<0.001) and Abeta38 (beta=0.288; p=0.001) and memory impairment, but not executive-attentional or visuospatial dysfunction. Tau protein levels did not correlate with cognitive measures. Conclusion CSF Abeta levels are altered in a subset of patients with early PD and relate to memory impairment. Our study suggests that alterations in Abeta protein metabolism may contribute to the heterogeneity in pattern and course of cognitive decline associated with PD. Longitudinal studies are needed to clarify the clinical significance of CSF Abeta peptides as prognostic biomarkers in PD.
|
|
| 4. |
- Andreasson, Ulf, 1968, et al.
(författare)
-
A Practical Guide to Immunoassay Method Validation.
- 2015
-
Ingår i: Frontiers in neurology. - : Frontiers Media SA. - 1664-2295. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- Biochemical markers have a central position in the diagnosis and management of patients in clinical medicine, and also in clinical research and drug development, also for brain disorders, such as Alzheimer's disease. The enzyme-linked immunosorbent assay (ELISA) is frequently used for measurement of low-abundance biomarkers. However, the quality of ELISA methods varies, which may introduce both systematic and random errors. This urges the need for more rigorous control of assay performance, regardless of its use in a research setting, in clinical routine, or drug development. The aim of a method validation is to present objective evidence that a method fulfills the requirements for its intended use. Although much has been published on which parameters to investigate in a method validation, less is available on a detailed level on how to perform the corresponding experiments. To remedy this, standard operating procedures (SOPs) with step-by-step instructions for a number of different validation parameters is included in the present work together with a validation report template, which allow for a well-ordered presentation of the results. Even though the SOPs were developed with the intended use for immunochemical methods and to be used for multicenter evaluations, most of them are generic and can be used for other technologies as well.
|
|
| 5. |
- Bjerke, Maria, 1977, et al.
(författare)
-
Confounding factors influencing amyloid Beta concentration in cerebrospinal fluid.
- 2010
-
Ingår i: International journal of Alzheimer's disease. - : Hindawi Limited. - 2090-0252. ; 2010
-
Tidskriftsartikel (refereegranskat)abstract
- Background. Patients afflicted with Alzheimer's disease (AD) exhibit a decrease in the cerebrospinal fluid (CSF) concentration of the 42 amino acid form of beta-amyloid (Abeta(42)). However, a high discrepancy between different centers in measured Abeta(42) levels reduces the utility of this biomarker as a diagnostic tool and in monitoring the effect of disease modifying drugs. Preanalytical and analytical confounding factors were examined with respect to their effect on the measured Abeta(42) level. Methods. Aliquots of CSF samples were either treated differently prior to Abeta(42) measurement or analyzed using different commercially available xMAP or ELISA assays. Results. Confounding factors affecting CSF Abeta(42) levels were storage in different types of test tubes, dilution with detergent-containing buffer, plasma contamination, heat treatment, and the origin of the immunoassays used for quantification. Conclusion. In order to conduct multicenter studies, a standardized protocol to minimize preanalytical and analytical confounding factors is warranted.
|
|
| 6. |
- Bos, I., et al.
(författare)
-
Cerebrospinal fluid biomarkers of neurodegeneration, synaptic integrity, and astroglial activation across the clinical Alzheimer's disease spectrum
- 2019
-
Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 15:5, s. 644-654
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: We investigated relations between amyloid-beta (A beta) status, apolipoprotein E (APOE) e4, and cognition, with cerebrospinal fluid markers of neurogranin (Ng), neurofilament light (NFL), YKL-40, and total tau (T-tau). Methods: We included 770 individuals with normal cognition, mild cognitive impairment, and Alzheimer's disease (AD)-type dementia from the EMIF-AD Multimodal Biomarker Discovery study. We tested the association of Ng, NFL, YKL-40, and T-tau with A beta status (Ab beta- vs. A beta+), clinical diagnosis APOE epsilon 4 carriership, baseline cognition, and change in cognition. Results: Ng and T-tau distinguished between A beta+ from A beta- individuals in each clinical group, whereas NFL and YKL-40 were associated with A beta+ in nondemented individuals only. APOE epsilon 4 carriership did not influence NFL, Ng, and YKL-40 in A beta+ individuals. NFL was the best predictor of cognitive decline in A beta+ individuals across the cognitive spectrum. Discussion: Axonal degeneration, synaptic dysfunction, astroglial activation, and altered tau metabolism are involved already in preclinical AD. NFL may be a useful prognostic marker. (C) 2019 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.
|
|
| 7. |
- Bridel, Claire, et al.
(författare)
-
Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology : A Systematic Review and Meta-analysis
- 2019
-
Ingår i: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149 .- 2168-6157. ; 76:9, s. 1035-1048
-
Forskningsöversikt (refereegranskat)abstract
- Importance Neurofilament light protein (NfL) is elevated in cerebrospinal fluid (CSF) of a number of neurological conditions compared with healthy controls (HC) and is a candidate biomarker for neuroaxonal damage. The influence of age and sex is largely unknown, and levels across neurological disorders have not been compared systematically to date.Objectives To assess the associations of age, sex, and diagnosis with NfL in CSF (cNfL) and to evaluate its potential in discriminating clinically similar conditions.Data Sources PubMed was searched for studies published between January 1, 2006, and January 1, 2016, reporting cNfL levels (using the search terms neurofilament light and cerebrospinal fluid) in neurological or psychiatric conditions and/or in HC.Study Selection Studies reporting NfL levels measured in lumbar CSF using a commercially available immunoassay, as well as age and sex.Data Extraction and Synthesis Individual-level data were requested from study authors. Generalized linear mixed-effects models were used to estimate the fixed effects of age, sex, and diagnosis on log-transformed NfL levels, with cohort of origin modeled as a random intercept.Main Outcome and Measure The cNfL levels adjusted for age and sex across diagnoses.Results Data were collected for 10 059 individuals (mean [SD] age, 59.7 [18.8] years; 54.1% female). Thirty-five diagnoses were identified, including inflammatory diseases of the central nervous system (n = 2795), dementias and predementia stages (n = 4284), parkinsonian disorders (n = 984), and HC (n = 1332). The cNfL was elevated compared with HC in a majority of neurological conditions studied. Highest levels were observed in cognitively impaired HIV-positive individuals (iHIV), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), and Huntington disease. In 33.3% of diagnoses, including HC, multiple sclerosis, Alzheimer disease (AD), and Parkinson disease (PD), cNfL was higher in men than women. The cNfL increased with age in HC and a majority of neurological conditions, although the association was strongest in HC. The cNfL overlapped in most clinically similar diagnoses except for FTD and iHIV, which segregated from other dementias, and PD, which segregated from atypical parkinsonian syndromes.Conclusions and Relevance These data support the use of cNfL as a biomarker of neuroaxonal damage and indicate that age-specific and sex-specific (and in some cases disease-specific) reference values may be needed. The cNfL has potential to assist the differentiation of FTD from AD and PD from atypical parkinsonian syndromes.
|
|
| 8. |
|
|
| 9. |
- Hansson, Sarah, 1976, et al.
(författare)
-
Reduced levels of amyloid-beta-binding proteins in cerebrospinal fluid from Alzheimer's disease patients.
- 2009
-
Ingår i: Journal of Alzheimer's disease : JAD. - 1387-2877. ; 16:2, s. 389-97
-
Tidskriftsartikel (refereegranskat)abstract
- Amyloid-beta(Abeta) aggregation is a major hallmark of Alzheimer's disease (AD). Previous studies have suggested that only unbound Abeta can take part in the aggregation process. Therefore, endogenous Abeta-binding proteins may have an important role in preventing AD. Here, we analyzed cerebrospinal fluid (CSF) samples from 35 subjects with AD, 18 subjects with frontotemporal dementia (FTD) and 29 non-demented controls to test if reduced Abeta-binding capacity in CSF is a specific feature of AD. A panel of known Abeta-binding CSF proteins, including beta-trace/prostaglandin D2 synthase (beta-trace), transthyretin (TTR), cystatin C (CysC) and alpha(1)-antitrypsin (AAT), were quantified and related to diagnosis and CSF levels of Abeta(1-38), Abeta(1-40) and Abeta(1-42). AD patients displayed a mild reduction in the CSF levels of beta-trace (p=0.020), CysC (p=0.017), AAT (p=0.019) and TTR (p=0.012) compared with controls. While the reductions in AAT and TTR were AD-specific, the levels of beta-trace and CysC were also reduced in FTD. As expected, CSF Abeta(1-42) was reduced in AD compared with controls (p=0.00005) and with FTD patients (p=0.015). Positive correlations between Abeta(1-42) and beta-trace, CysC and TTR, respectively, were seen only in the AD group, suggesting that deficient Abeta-binding capacity in CSF may contribute to the amyloidogenic process in AD.
|
|
| 10. |
- Hellwig, K., et al.
(författare)
-
Neurogranin and YKL-40: independent markers of synaptic degeneration and neuroinflammation in Alzheimer's disease
- 2015
-
Ingår i: Alzheimers Research & Therapy. - : Springer Science and Business Media LLC. - 1758-9193. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Neuroinflammation and synaptic degeneration are major neuropathological hallmarks in Alzheimer's disease (AD). Neurogranin and YKL-40 in cerebrospinal fluid (CSF) are newly discovered markers indicating synaptic damage and microglial activation, respectively. Methods: CSF samples from 95 individuals including 39 patients with AD dementia (AD-D), 13 with mild cognitive impairment (MCI) due to AD (MCI-AD), 29 with MCI not due to AD (MCI-o) and 14 patients with non-AD dementias (non-AD-D) were analyzed for neurogranin and YKL-40. Results: Patients with dementia or MCI due to AD showed elevated levels of CSF neurogranin (p < 0.001 for AD-D and p < 0.05 for MCI-AD) and YKL-40 (p < 0.05 for AD-D and p = 0.15 for MCI-AD) compared to mildly cognitively impaired subjects not diagnosed with AD. CSF levels of neurogranin and YKL-40 did not differ between MCI not due to AD and non-AD dementias. In AD subjects no correlation between YKL-40 and neurogranin was found. The CSF neurogranin levels correlated moderately with tau and p-tau but not with A beta 42 or the MMSE in AD samples. No relevant associations between YKL-40 and MMSE or the core AD biomarkers, A beta 42, t-tau and p-tau were found in AD subjects. Conclusions: Neurogranin and YKL-40 are promising AD biomarkers, independent of and complementary to the established core AD biomarkers, reflecting additional pathological changes in the course of AD.
|
|
