| 1. |
- Bjerke, Maria, 1977, et al.
(författare)
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Cerebrospinal Fluid Matrix Metalloproteinases and Tissue Inhibitor of Metalloproteinases in Combination with Subcortical and Cortical Biomarkers in Vascular Dementia and Alzheimer's Disease.
- 2011
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Ingår i: Journal of Alzheimer's disease : JAD. - 1387-2877. ; 27:3, s. 665-676
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) and vascular dementia (VaD) are intertwined by mixed dementia (MD) harboring varying degrees of AD pathology in combination with cerebrovascular disease. The aim was to assess whether there is a difference in the cerebrospinal fluid (CSF) profile, of selected proteins, between patients with VaD and MD with subcortical vascular disease (SVD), AD, and healthy controls that could contribute in the separation of the groups. The study included 30 controls, 26 SVD patients (9 VaD and 17 MD) and 30 AD patients. The protein panel included total tau (T-tau), hyperphosphorylated tau 181 (P-tau181), amyloid β 1-42 (Aβ1-42), neurofilament light (NF-L), myelin basic protein (MBP), heart fatty acid binding protein (H-FABP), matrix metalloproteinases (MMP-1, -2, -3, -9, and -10), and tissue inhibitors of metalloproteinases (TIMP-1 and -2). Immunochemical methods were utilized for quantification of the proteins in CSF and data analysis was performed with a multivariate discriminant algorithm. The concentrations of MBP, TIMP-1, P-tau181, NF-L, T-tau, MMP-9, Aβ1-42, and MMP-2 contributed the most to the separation between SVD and AD, with a sensitivity of 89% and a specificity of 90% (AUC = 0.92). MBP and NF-L performed the best in discriminating SVD from controls, while T-tau and Aβ1-42 contributed the most in segregating AD from controls. The CSF biomarkers reflecting AD pathology (T-tau, P-tau181, and Aβ1-42), white matter lesions (NF-L and MBP) and matrix remodeling (MMP-9 and TIMP-1) perform well in differentiating between SVD and AD patients.
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| 2. |
- Bjerke, Maria, 1977, et al.
(författare)
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Confounding factors influencing amyloid Beta concentration in cerebrospinal fluid.
- 2010
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Ingår i: International journal of Alzheimer's disease. - : Hindawi Limited. - 2090-0252. ; 2010
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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.
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| 3. |
- Blennow, Kaj, 1958, et al.
(författare)
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No neurochemical evidence of brain injury after blast overpressure by repeated explosions or firing heavy weapons.
- 2011
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Ingår i: Acta neurologica Scandinavica. - : Hindawi Limited. - 1600-0404 .- 0001-6314. ; 123, s. 245-51
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Tidskriftsartikel (refereegranskat)abstract
- Blennow K, Jonsson M, Andreasen N, Rosengren L, Wallin A, Hellström PA, Zetterberg H. No neurochemical evidence of brain injury after blast overpressure by repeated explosions or firing heavy weapons.Acta Neurol Scand: DOI: 10.1111/j.1600-0404.2010.01408.x .(c) 2010 John Wiley & Sons A/S. Background - Psychiatric and neurological symptoms are common among soldiers exposed to blast without suffering a direct head injury. It is not known whether such symptoms are direct consequences of blast overpressure. Objective - To examine if repeated detonating explosions or firing if of heavy weapons is associated with neurochemical evidence of brain damage. Materials and methods - Three controlled experimental studies. In the first, army officers were exposed to repeated firing of a FH77B howitzer or a bazooka. Cerebrospinal fluid (CSF) was taken post-exposure to measure biomarkers for brain damage. In the second, officers were exposed for up to 150 blasts by firing a bazooka, and in the third to 100 charges of detonating explosives of 180 dB. Serial serum samples were taken after exposure. Results were compared with a control group consisting of 19 unexposed age-matched healthy volunteers. Results - The CSF biomarkers for neuronal/axonal damage (tau and neurofilament protein), glial cell injury (GFAP and S-100b), blood-brain barrier damage (CSF/serum albumin ratio) and hemorrhages (hemoglobin and bilirubin) and the serum GFAP and S-100b showed normal and stable levels in all exposed officers. Discussion - Repeated exposure to high-impact blast does not result in any neurochemical evidence of brain damage. These findings are of importance for soldiers regularly exposed to high-impact blast when firing artillery shells or other types of heavy weapons.
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| 4. |
- Eckerström, Carl, et al.
(författare)
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Combination of Hippocampal Volume and Cerebrospinal Fluid Biomarkers Improves Predictive Value in Mild Cognitive Impairment.
- 2010
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 29:4, s. 294-300
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mild cognitive impairment (MCI) is a heterogeneous condition, and the prognosis differs within the group. Recent findings suggest that hippocampal volumetry and CSF biomarkers can be used to predict which MCI patients have an underlying neurodegenerative disorder. Objective: To examine the combined predictive value of hippocampal volume and CSF levels of total tau (T-tau) and beta-amyloid(42) (Abeta(42)) in stable and converting MCI patients. The participants (n = 68) included patients with MCI at baseline and who converted to dementia by the time of the 2-year follow-up (n = 21), stable MCI patients (n = 21) and healthy controls (n = 26). Methods: The Göteborg MCI study is a clinically based longitudinal study with biannual clinical assessments. Hippocampal volumetry was performed manually, based on data from the 0.5-tesla MRI investigations at baseline. Baseline CSF levels of T-tau and Abeta(42) were measured using commercially available, enzyme-linked immunosorbent assays. Results: The converting MCI group had significantly smaller left hippocampi, lower CSF Abeta(42) and higher T-tau compared to both the stable MCI group and the healthy controls. Multivariate analysis revealed that a combination of the variables outperformed the prognostic ability of the separate variables. Conclusions: Hippocampal volumes supplement the prognostic accuracy of CSF Abeta(42) and T-tau in MCI.
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| 5. |
- Hansson, Oskar, et al.
(författare)
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Evaluation of plasma Abeta(40) and Abeta(42) as predictors of conversion to Alzheimer's disease in patients with mild cognitive impairment.
- 2010
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Ingår i: Neurobiology of aging. - : Elsevier BV. - 1558-1497 .- 0197-4580. ; 31:3, s. 357-67
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Tidskriftsartikel (refereegranskat)abstract
- Numerous studies have shown a marked decrease of beta-amyloid(42) (Abeta(42)) in the cerebrospinal fluid (CSF) of patients with incipient Alzheimer's disease (AD). However, studies on Abeta in plasma are contradictory, and show very marginal differences between patients and controls. Here, we analyzed plasma samples using a new multiplex immunoassay for simultaneous analysis of Abeta(1-40), Abeta(n-40), Abeta(1-42), and Abeta(n-42). The plasma samples were obtained at baseline from two independent cohorts of patients with mild cognitive impairment (MCI) and age-matched controls. In the first cohort, 41% of the 117 MCI cases converted to AD during a clinical follow-up period of 4-7 years. In the second cohort, 14% of the 110 MCI subjects developed AD during a clinical follow-up period of 2-4 years. None of the plasma Abeta isoforms differed between MCI patients that subsequently developed AD and healthy controls or stable MCI patients. The Cox proportional hazards model did not reveal any differences in the probability of progression from MCI to AD related to plasma Abeta levels. In contrast, low levels of Abeta(1-42) in CSF were strongly associated with increased risk of future AD. The absence of a change in plasma Abeta in incipient AD, despite the marked change in CSF, may be explained by the lack of a correlation between the levels of Abeta(1-42) in CSF and plasma. In conclusion, the results show that CSF biomarkers are better predictors of progression to AD than plasma Abeta isoforms.
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| 6. |
- Johansson, Per, et al.
(författare)
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Cerebrospinal Fluid Biomarkers for Alzheimer's Disease: Diagnostic Performance in a Homogeneous Mono-Center Population
- 2011
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 24:3, s. 537-546
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Tidskriftsartikel (refereegranskat)abstract
- The cerebrospinal fluid (CSF) biomarkers amyloid-beta (A beta)(1-42), T-tau, and P-tau have good diagnostic accuracy for clinically diagnosed Alzheimer's disease (AD). However, in multi-center studies, the predictive values of the CSF biomarkers have been lower, possibly due to differences in procedures for lumbar puncture and CSF handling and storage, and to differences in patient populations, clinical evaluations, and diagnostic procedures. Here we investigate the diagnostic accuracy of CSF biomarkers in a well defined homogeneous mono-center population. We also evaluate an extended panel of amyloid related biomarkers. Sixty consecutive patients admitted for cognitive impairment to a memory clinic were recruited. The participants included patients with AD or mild cognitive impairment (MCI) diagnosed with AD upon follow-up (n = 32), patients with stable MCI (n = 13), patients with other dementias diagnosed at primary evaluation or upon follow-up (n = 15), and healthy controls (n = 20). CSF was analyzed for A beta(1-42), T-tau, P-tau, A beta(X-38), A beta(X-40), A beta(X-42), sA beta PP alpha, and sA beta PP beta. In multivariate analysis, the core biomarkers A beta(1-42), T-tau, and P-tau demonstrated a high ability to diagnose AD versus the combined groups of controls and stable MCI, with an area under the receiver operating characteristic curve (AUROC) of 0.97 (95% CI 0.93-1.00, p < 0.0001). The additional biomarkers only marginally increased AUROC to 0.98 (95% CI 0.95-1.00, p < 0.0001), this increase mainly mediated by A beta(X-42). In conclusion, CSF biomarkers A beta(1-42), T-tau, and P-tau have very high diagnostic accuracy in a well defined cohort of untreated patients, demonstrating the excellent potency of CSF biomarkers to identify pathological processes in AD when a stringent analytical protocol is used.
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| 7. |
- Johansson, Per, 1966, et al.
(författare)
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Mild dementia is associated with increased adrenal secretion of cortisol and precursor sex steroids in women.
- 2011
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Ingår i: Clinical endocrinology. - : Wiley. - 1365-2265 .- 0300-0664. ; 75:3, s. 301-308
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Tidskriftsartikel (refereegranskat)abstract
- Context Sex steroid levels decrease with increasing age, but little is known whether this is of importance for the age-related decline in cognitive function. Design and patients A cross-sectional study of 50 (26 men) consecutive patients under primary evaluation of cognitive impairment (D group) and 18 (9 men) matched healthy controls (C group). Measurements Sex steroid and precursor levels were determined in serum and, when measurable, in cerebrospinal fluid (CSF) using gas chromatography/mass spectroscopy (GC-MS) or liquid chromatography/mass spectroscopy (LC-MS). Sex hormone binding globulin (SHBG) and cortisol concentrations were measured using conventional assays. Results Patients in the D group had higher 24-h urine cortisol levels and increased serum levels of dehydroepiandrosterone (DHEA) and its sulphate ester dihydroepiandrosterone sulphate (DHEAS), androsterone (ADT), and oestrone (E1) and its sulphate ester E1S, compared with the controls. When men and women were analysed separately, increased serum concentrations of E1 and E1S were observed in both D men and D women, whereas increased levels of other sex steroids and cortisol were seen only in D women. Conclusions In both D men and women, serum E1 and E1S levels were increased, whereas other changes were gender specific and only seen in D women. Further studies are needed to determine whether these changes are a cause of, or merely a consequence of, cognitive impairment in elderly subjects.
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| 8. |
- Jonsson, Michael, 1955, et al.
(författare)
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Cerebrospinal fluid biomarkers of white matter lesions - cross-sectional results from the LADIS study.
- 2010
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Ingår i: European journal of neurology. - : Wiley. - 1468-1331 .- 1351-5101. ; 17:3, s. 377-382
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: White matter lesions (WMLs) caused by small vessel disease are common in elderly people and contribute to cognitive impairment. There are no established biochemical markers for WMLs. We aimed to study the relation between degree of WMLs rated on magnetic resonance imaging of the brain and cerebrospinal fluid (CSF) levels of structural biomarkers associated with Alzheimer's disease (AD) and subcortical vascular dementia. Methods: Fifty-three non-demented elderly individuals with WMLs were subjected to lumbar puncture. Degree of WMLs was rated using the Fazekas scale. Volumetric assessment of WMLs was performed. CSF samples were analyzed for the 40 and 42 amino acid fragments of amyloid beta, alpha- and beta-cleaved soluble amyloid precursor protein, total tau (T-tau), hyperphosphorylated tau (P-tau(181)), neurofilament light protein (NFL), sulfatide and CSF/Serum-albumin ratio. Results: Fifteen subjects had mild, 23 had moderate and 15 had severe degree of WMLs. CSF-NFL levels differed between the groups (P < 0.001) and correlated with the volume of WMLs (r = 0.477, P < 0.001). CSF sulfatide concentration displayed similar changes but less strongly. T-tau, P-tau(181) and the different amyloid markers as well as CSF/S-albumin ratio did not differ significantly between the groups. Conclusions: The association of increased CSF-NFL levels with increasing severity of WMLs in non-demented subjects suggests that NFL is a marker for axonal damage in response to small vessel disease in the brain. This manifestation may be distinct from or earlier than the neurodegenerative process seen in AD, as reflected by the lack of association between WMLs and AD biomarkers.
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| 9. |
- Landgren, Sara, 1980, et al.
(författare)
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No Association of VEGF Polymorphims with Alzheimer's Disease
- 2010
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Ingår i: NeuroMolecular Medicine. - : Springer Science and Business Media LLC. - 1535-1084 .- 1559-1174. ; 12:3, s. 224-228
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Tidskriftsartikel (refereegranskat)abstract
- The vascular hypothesis of Alzheimer's disease (AD) has brought the vascular endothelial growth factor (VEGF) into focus. The genomic region including the VEGF gene has been linked to AD and single nucleotide polymorphisms (SNPs) of the VEGF have in previous studies been associated with AD risk. To further evaluate these findings, we genotyped two SNPs in the VEGF gene (rs699947 [-2578]) and rs1570360 [-1154]) by TaqMan Allelic Discrimination in a study sample including AD patients (n = 801) and controls (n = 286). In a subgroup of the population these SNPs were analyzed in relation to APOE epsilon 4 genotype, to cerebrospinal fluid biomarkers (T-tau, P-tau, and beta(42)-Amyloid) as well as to neuropathological markers for AD (neurofibrillary tangles and senile plaques). No significant associations with risk for AD or any of the studied biomarkers could be found in this study, thus not supporting VEGF as being a major risk gene for AD.
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| 10. |
- Mattsson, Niklas, 1979, et al.
(författare)
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Cerebrospinal Fluid Microglial Markers in Alzheimer's Disease: Elevated Chitotriosidase Activity but Lack of Diagnostic Utility
- 2011
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Ingår i: NeuroMolecular Medicine. - : Springer Science and Business Media LLC. - 1535-1084 .- 1559-1174. ; 13:2, s. 151-159
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Tidskriftsartikel (refereegranskat)abstract
- Activated microglial cells, which are the resident macrophages of the central nervous system, surround amyloid beta-plaques in Alzheimer's disease (AD) brains. Inflammation including microglial activation may contribute in AD pathogenesis, and biomarkers for this process may thus be of value to study AD pathogenesis and might facilitate development of therapies targeting these cells. We therefore examined cerebrospinal fluid (CSF) biomarkers in patients with AD, other dementias, mild cognitive impairment and in healthy controls. Samples were analyzed for markers with known association to macrophage activity, including chitotriosidase, YKL-40 (CHI3L1, HC gp-39) and chemokine CC motif ligand 2 (CCL2, MCP1). Patients with AD had higher chitotriosidase activity than controls and patients with stable mild cognitive impairment, consistent with the presence of activated microglial cells in AD brains, but with large overlaps between groups. CCL2 and YKL-40 concentrations did not differ among groups. Microglial markers are unlikely to be useful for AD diagnosis, but might be useful for identification of distinct subgroups of patients, and for the development and implementation of drugs targeting microglial pathology.
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