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- Wellington, H., et al.
(author)
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CSF neurogranin or tau distinguish typical and atypical Alzheimer disease
- 2018
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In: Annals of Clinical and Translational Neurology. - : Wiley. - 2328-9503. ; 5:2, s. 162-171
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Journal article (peer-reviewed)abstract
- Objective: To assess whether high levels of cerebrospinal fluid neurogranin are found in atypical as well as typical Alzheimer's disease. Methods: Immunoassays were used to measure cerebrospinal fluid neurogranin in 114 participants including healthy controls (n=27), biomarker-proven amnestic Alzheimer's disease (n=68), and the atypical visual variant of Alzheimer's (n=19) according to international criteria. CSF total-tau, A beta 42, and neurofilament light concentrations were investigated using commercially available assays. All affected individuals had T1-weighted volumetric MR images available for analysis of whole and regional brain volumes. Associations between neurogranin, brain volumes, total-tau, A beta 42, and neurofilament light were assessed. Results: Median cerebrospinal fluid neurogranin concentrations were higher in typical and atypical Alzheimer's compared to controls (P<0.001 and P=0.005). Both neurogranin and total-tau concentrations, but not neurofilament light and A beta 42, were higher in typical Alzheimer's compared to atypical patients (P=0.004 and P=0.03). There were significant differences in the left hippocampus and right and left superior parietal lobules in atypical patients, which were larger (P=0.03) and smaller (P=0.001 and P<0.001), respectively, compared to typical patients. We found no evidence of associations between neurogranin and brain volumes but a strong association with total-tau (P<0.001) and a weaker association with neurofilament light (P=0.005). Interpretation: These results show significant differences in neurogranin and total-tau between typical and atypical patients, which may relate to factors other than disease topography. The differential relationships between neurogranin, total-tau and neurofilament light in the Alzheimer's variants, provide evidence for mechanistically distinct and coupled markers of neurodegeneration.
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- Paterson, Ross W, et al.
(author)
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Cerebrospinal fluid in the differential diagnosis of Alzheimer's disease: clinical utility of an extended panel of biomarkers in a specialist cognitive clinic
- 2018
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In: Alzheimer's research & therapy. - : Springer Science and Business Media LLC. - 1758-9193. ; 10, s. 1-11
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Journal article (peer-reviewed)abstract
- Cerebrospinal fluid (CSF) biomarkers are increasingly being used to support a diagnosis of Alzheimer's disease (AD). Their clinical utility for differentiating AD from non-AD neurodegenerative dementias, such as dementia with Lewy bodies (DLB) or frontotemporal dementia (FTD), is less well established. We aimed to determine the diagnostic utility of an extended panel of CSF biomarkers to differentiate AD from a range of other neurodegenerative dementias.We used immunoassays to measure conventional CSF markers of amyloid and tau pathology (amyloid beta (Aβ)1-42, total tau (T-tau), and phosphorylated tau (P-tau)) as well as amyloid processing (AβX-38, AβX-40, AβX-42, soluble amyloid precursor protein (sAPP)α, and sAPPβ), large fibre axonal degeneration (neurofilament light chain (NFL)), and neuroinflammation (YKL-40) in 245 patients with a variety of dementias and 30 controls. Patients fulfilled consensus criteria for AD (n=156), DLB (n=20), behavioural variant frontotemporal dementia (bvFTD; n=45), progressive non-fluent aphasia (PNFA; n=17), and semantic dementia (SD; n=7); approximately 10% were pathology/genetically confirmed (n=26). Global tests based on generalised least squares regression were used to determine differences between groups. Non-parametric receiver operating characteristic (ROC) curves and area under the curve (AUC) analyses were used to quantify how well each biomarker discriminated AD from each of the other diagnostic groups (or combinations of groups). CSF cut-points for the major biomarkers found to have diagnostic utility were validated using an independent cohort which included causes of AD (n=104), DLB (n=5), bvFTD (n=12), PNFA (n=3), SD (n=9), and controls (n=10).There were significant global differences in Aβ1-42, T-tau, T-tau/Aβ1-42 ratio, P-tau-181, NFL, AβX-42, AβX-42/X-40 ratio, APPα, and APPβ between groups. At a fixed sensitivity of 85%, AβX-42/X-40 could differentiate AD from controls, bvFTD, and SD with specificities of 93%, 85%, and 100%, respectively; for T-tau/Aβ1-42 these specificities were 83%, 70%, and 86%. AβX-42/X-40 had similar or higher specificity than Aβ1-42. No biomarker or ratio could differentiate AD from DLB or PNFA with specificity >50%. Similar sensitivities and specificities were found in the independent validation cohort for differentiating AD and other dementias and in a pathology/genetically confirmed sub-cohort.CSF AβX-42/X-40 and T-tau/Aβ1-42 ratios have utility in distinguishing AD from controls, bvFTD, and SD. None of the biomarkers tested had good specificity at distinguishing AD from DLB or PNFA.
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