1. |
- Ashton, Nicholas J., et al.
(författare)
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Differential roles of Aβ42/40, p-tau231 and p-tau217 for Alzheimer's trial selection and disease monitoring.
- 2022
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Ingår i: Nature medicine. - : Springer Science and Business Media LLC. - 1546-170X .- 1078-8956. ; 28:12, s. 2555-2562
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Tidskriftsartikel (refereegranskat)abstract
- Blood biomarkers indicative of Alzheimer's disease (AD) pathology are altered in both preclinical and symptomatic stages of the disease. Distinctive biomarkers may be optimal for the identification of AD pathology or monitoring of disease progression. Blood biomarkers that correlate with changes in cognition and atrophy during the course of the disease could be used in clinical trials to identify successful interventions and thereby accelerate the development of efficient therapies. When disease-modifying treatments become approved for use, efficient blood-based biomarkers might also inform on treatment implementation and management in clinical practice. In the BioFINDER-1 cohort, plasma phosphorylated (p)-tau231 and amyloid-β42/40 ratio were more changed at lower thresholds of amyloid pathology. Longitudinally, however, only p-tau217 demonstrated marked amyloid-dependent changes over 4-6years in both preclinical and symptomatic stages of the disease, with no such changes observed in p-tau231, p-tau181, amyloid-β42/40, glial acidic fibrillary protein or neurofilament light. Only longitudinal increases of p-tau217 were also associated with clinical deterioration and brain atrophy in preclinical AD. The selective longitudinal increase of p-tau217 and its associations with cognitive decline and atrophy was confirmed in an independent cohort (Wisconsin Registry for Alzheimer's Prevention). These findings support the differential association of plasma biomarkers with disease development and strongly highlight p-tau217 as a surrogate marker of disease progression in preclinical and prodromal AD, with impact for the development of new disease-modifying treatments.
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2. |
- Bridel, Claire, et al.
(författare)
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Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology : A Systematic Review and Meta-analysis
- 2019
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Ingår i: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149 .- 2168-6157. ; 76:9, s. 1035-1048
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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.
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3. |
- Brum, Wagner S., et al.
(författare)
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A two-step workflow based on plasma p-tau217 to screen for amyloid β positivity with further confirmatory testing only in uncertain cases
- 2023
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Ingår i: Nature Aging. - 2662-8465. ; 3:9, s. 1079-1090
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Tidskriftsartikel (refereegranskat)abstract
- Cost-effective strategies for identifying amyloid-beta (A beta) positivity in patients with cognitive impairment are urgently needed with recent approvals of anti-A beta immunotherapies for Alzheimer's disease (AD). Blood biomarkers can accurately detect AD pathology, but it is unclear whether their incorporation into a full diagnostic workflow can reduce the number of confirmatory cerebrospinal fluid (CSF) or positron emission tomography (PET) tests needed while accurately classifying patients. We evaluated a two-step workflow for determining A beta-PET status in patients with mild cognitive impairment (MCI) from two independent memory clinic-based cohorts (n = 348). A blood-based model including plasma tau protein 217 (p-tau217), age and APOE epsilon 4 status was developed in BioFINDER-1 (area under the curve (AUC) = 89.3%) and validated in BioFINDER-2 (AUC = 94.3%). In step 1, the blood-based model was used to stratify the patients into low, intermediate or high risk of A beta-PET positivity. In step 2, we assumed referral only of intermediate-risk patients to CSF A beta 42/A beta 40 testing, whereas step 1 alone determined A beta-status for low-and high-risk groups. Depending on whether lenient, moderate or stringent thresholds were used in step 1, the two-step workflow overall accuracy for detecting A beta-PET status was 88.2%, 90.5% and 92.0%, respectively, while reducing the number of necessary CSF tests by 85.9%, 72.7% and 61.2%, respectively. In secondary analyses, an adapted version of the BioFINDER-1 model led to successful validation of the two-step workflow with a different plasma p-tau217 immunoassay in patients with cognitive impairment from the TRIAD cohort (n = 84). In conclusion, using a plasma p-tau217-based model for risk stratification of patients with MCI can substantially reduce the need for confirmatory testing while accurately classifying patients, offering a cost-effective strategy to detect AD in memory clinic settings.
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4. |
- Cullen, Nicholas C., et al.
(författare)
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Test-retest variability of plasma biomarkers in Alzheimer's disease and its effects on clinical prediction models
- 2023
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Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 19:3, s. 797-806
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION The effect of random error on the performance of blood-based biomarkers for Alzheimer's disease (AD) must be determined before clinical implementation. METHODS We measured test-retest variability of plasma amyloid beta (A beta)42/A beta 40, neurofilament light (NfL), glial fibrillary acidic protein (GFAP), and phosphorylated tau (p-tau)217 and simulated effects of this variability on biomarker performance when predicting either cerebrospinal fluid (CSF) A beta status or conversion to AD dementia in 399 non-demented participants with cognitive symptoms. RESULTS Clinical performance was highest when combining all biomarkers. Among single-biomarkers, p-tau217 performed best. Test-retest variability ranged from 4.1% (A beta 42/A beta 40) to 25% (GFAP). This variability reduced the performance of the biomarkers (approximate to Delta AUC [area under the curve] -1% to -4%) with the least effects on models with p-tau217. The percent of individuals with unstable predicted outcomes was lowest for the multi-biomarker combination (14%). DISCUSSION Clinical prediction models combining plasma biomarkers-particularly p-tau217-exhibit high performance and are less effected by random error. Individuals with unstable predicted outcomes ("gray zone") should be recommended for further tests.
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5. |
- Eratne, D., et al.
(författare)
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Cerebrospinal fluid neurofilament light chain differentiates primary psychiatric disorders from rapidly progressive, Alzheimer's disease and frontotemporal disorders in clinical settings
- 2022
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Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 18:11, s. 2218-2233
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Many patients with cognitive and neuropsychiatric symptoms face diagnostic delay and misdiagnosis. We investigated whether cerebrospinal fluid (CSF) neurofilament light (NfL) and total-tau (t-tau) could assist in the clinical scenario of differentiating neurodegenerative (ND) from psychiatric disorders (PSY), and rapidly progressive disorders. Methods Biomarkers were examined in patients from specialist services (ND and PSY) and a national Creutzfeldt-Jakob registry (Creutzfeldt-Jakob disease [CJD] and rapidly progressive dementias/atypically rapid variants of common ND, RapidND). Results A total of 498 participants were included: 197 ND, 67 PSY, 161 CJD, 48 RapidND, and 20 controls. NfL was elevated in ND compared to PSY and controls, with highest levels in CJD and RapidND. NfL distinguished ND from PSY with 95%/78% positive/negative predictive value, 92%/87% sensitivity/specificity, 91% accuracy. NfL outperformed t-tau in most real-life clinical diagnostic dilemma scenarios, except distinguishing CJD from RapidND. Discussion We demonstrated strong generalizable evidence for the diagnostic utility of CSF NfL in differentiating ND from psychiatric disorders, with high accuracy.
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6. |
- Eratne, D., et al.
(författare)
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Plasma neurofilament light chain protein is not increased in treatment-resistant schizophrenia and first-degree relatives
- 2022
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Ingår i: Australian and New Zealand Journal of Psychiatry. - : SAGE Publications. - 0004-8674 .- 1440-1614. ; 56:10
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Schizophrenia, a complex psychiatric disorder, is often associated with cognitive, neurological and neuroimaging abnormalities. The processes underlying these abnormalities, and whether a subset of people with schizophrenia have a neuroprogressive or neurodegenerative component to schizophrenia, remain largely unknown. Examining fluid biomarkers of diverse types of neuronal damage could increase our understanding of these processes, as well as potentially provide clinically useful biomarkers, for example with assisting with differentiation from progressive neurodegenerative disorders such as Alzheimer and frontotemporal dementias. Methods: This study measured plasma neurofilament light chain protein (NfL) using ultrasensitive Simoa technology, to investigate the degree of neuronal injury in a well-characterised cohort of people with treatment-resistant schizophrenia on clozapine (n = 82), compared to first-degree relatives (an at-risk group, n = 37), people with schizophrenia not treated with clozapine (n = 13), and age- and sex-matched controls (n = 59). Results: We found no differences in NfL levels between treatment-resistant schizophrenia (mean NfL, M = 6.3 pg/mL, 95% confidence interval: [5.5, 7.2]), first-degree relatives (siblings, M = 6.7 pg/mL, 95% confidence interval: [5.2, 8.2]; parents, M after adjusting for age = 6.7 pg/mL, 95% confidence interval: [4.7, 8.8]), controls (M = 5.8 pg/mL, 95% confidence interval: [5.3, 6.3]) and not treated with clozapine (M = 4.9 pg/mL, 95% confidence interval: [4.0, 5.8]). Exploratory, hypothesis-generating analyses found weak correlations in treatment-resistant schizophrenia, between NfL and clozapine levels (Spearman's r = 0.258, 95% confidence interval: [0.034, 0.457]), dyslipidaemia (r = 0.280, 95% confidence interval: [0.064, 0.470]) and a negative correlation with weight (r = -0.305, 95% confidence interval: [-0.504, -0.076]). Conclusion: Treatment-resistant schizophrenia does not appear to be associated with neuronal, particularly axonal degeneration. Further studies are warranted to investigate the utility of NfL to differentiate treatment-resistant schizophrenia from neurodegenerative disorders such as behavioural variant frontotemporal dementia, and to explore NfL in other stages of schizophrenia such as the prodome and first episode.
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7. |
- Eratne, D., et al.
(författare)
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Plasma neurofilament light in behavioural variant frontotemporal dementia compared to mood and psychotic disorders
- 2023
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Ingår i: Australian and New Zealand Journal of Psychiatry. - 0004-8674. ; 58:1, s. 70-81
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Blood biomarkers of neuronal injury such as neurofilament light (NfL) show promise to improve diagnosis of neurodegenerative disorders and distinguish neurodegenerative from primary psychiatric disorders (PPD). This study investigated the diagnostic utility of plasma NfL to differentiate behavioural variant frontotemporal dementia (bvFTD, a neurodegenerative disorder commonly misdiagnosed initially as PPD), from PPD, and performance of large normative/reference data sets and models. Methods: Plasma NfL was analysed in major depressive disorder (MDD, n = 42), bipolar affective disorder (BPAD, n = 121), treatment-resistant schizophrenia (TRS, n = 82), bvFTD (n = 22), and compared to the reference cohort (Control Group 2, n = 1926, using GAMLSS modelling), and age-matched controls (Control Group 1, n = 96, using general linear models). Results: Large differences were seen between bvFTD (mean NfL 34.9 pg/mL) and all PPDs and controls (all < 11 pg/mL). NfL distinguished bvFTD from PPD with high accuracy, sensitivity (86%), and specificity (88%). GAMLSS models using reference Control Group 2 facilitated precision interpretation of individual levels, while performing equally to or outperforming models using local controls. Slightly higher NfL levels were found in BPAD, compared to controls and TRS. Conclusions: This study adds further evidence on the diagnostic utility of NfL to distinguish bvFTD from PPD of high clinical relevance to a bvFTD differential diagnosis, and includes the largest cohort of BPAD to date. Using large reference cohorts, GAMLSS modelling and the interactive Internet-based application we developed, may have important implications for future research and clinical translation. Studies are underway investigating utility of plasma NfL in diverse neurodegenerative and primary psychiatric conditions in real-world clinical settings.
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8. |
- Gobom, Johan, et al.
(författare)
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Antibody-free measurement of cerebrospinal fluid tau phosphorylation across the Alzheimer's disease continuum.
- 2022
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Ingår i: Molecular neurodegeneration. - : Springer Science and Business Media LLC. - 1750-1326. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease is characterized by an abnormal increase of phosphorylated tau (pTau) species in the CSF. It has been suggested that emergence of different pTau forms may parallel disease progression. Therefore, targeting multiple specific pTau forms may allow for a deeper understanding of disease evolution and underlying pathophysiology. Current immunoassays measure pTau epitopes separately and may capture phosphorylated tau fragments of different length depending on the non-pTau antibody used in the assay sandwich pair, which bias the measurement.We developed the first antibody-free mass spectrometric method to simultaneously measure multiple phosphorylated epitopes in CSF tau: pT181, pS199, pS202, pT205, pT217, pT231, and pS396. The method was first evaluated in biochemically defined Alzheimer's disease and control CSF samples (n=38). All seven pTau epitopes clearly separated Alzheimer's disease from non-AD (p<0.001, AUC=0.84-0.98). We proceeded with clinical validation of the method in the TRIAD (n=165) and BioFINDER-2 cohorts (n=563), consisting of patients across the full Alzheimer's disease continuum, including also young controls (<40years), as well as patients with frontotemporal dementia and other neurodegenerative disorders.Increased levels of all phosphorylated epitopes were found in Alzheimer's disease dementia and Aβ positron emission tomography-positive patients with mild cognitive impairment compared with Aβ-negative controls. For Alzheimer's disease dementia compared with Aβ-negative controls, the best biomarker performance was observed for pT231 (TRIAD: AUC=98.73%, fold change=7.64; BioFINDER-2: AUC=91.89%, fold change=10.65), pT217 (TRIAD: AUC=99.71%, fold change=6.33; BioFINDER-2: AUC=98.12%, fold change=8.83) and pT205 (TRIAD: AUC=99.07%, fold change=5.34; BioFINDER-2: AUC=93.51%, fold change=3.92). These phospho-epitopes also discriminated between Aβ-positive and Aβ-negative cognitively unimpaired individuals: pT217 (TRIAD: AUC=83.26, fold change=2.39; BioFINDER-2: AUC=91.05%, fold change=3.29), pT231 (TRIAD: AUC=86.25, fold change=3.80; BioFINDER-2: AUC=78.69%, fold change=3.65) and pT205 (TRIAD: AUC=71.58, fold change=1.51; BioFINDER-2: AUC=71.11%, fold change=1.70).While an increase was found for all pTau species examined, the highest fold change in Alzheimer's disease was found for pT231, pT217 and pT205. Simultaneous antibody-free measurement of pTau epitopes by mass spectrometry avoids possible bias caused by differences in antibody affinity for modified or processed forms of tau, provides insights into tau pathophysiology and may facilitate clinical trials on tau-based drug candidates.
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9. |
- Janelidze, Shorena, et al.
(författare)
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Cerebrospinal fluid neurogranin and YKL-40 as biomarkers of Alzheimer's disease.
- 2016
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Ingår i: Annals of clinical and translational neurology. - : Wiley. - 2328-9503. ; 3:1, s. 12-20
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Tidskriftsartikel (refereegranskat)abstract
- Widespread implementation of cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) in clinical settings requires improved accuracy for diagnosis of prodromal disease and for distinguishing AD from non-AD dementias. Novel and promising CSF biomarkers include neurogranin, a marker of synaptic degeneration, and YKL-40, a marker of neuroinflammation.
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10. |
- Janelidze, Shorena, et al.
(författare)
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Concordance Between Different Amyloid Immunoassays and Visual Amyloid Positron Emission Tomographic Assessment.
- 2017
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Ingår i: JAMA neurology. - : American Medical Association (AMA). - 2168-6157 .- 2168-6149. ; 74:12, s. 1492-1501
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Tidskriftsartikel (refereegranskat)abstract
- Visual assessment of amyloid positron emission tomographic (PET) images has been approved by regulatory authorities for clinical use. Several immunoassays have been developed to measure β-amyloid (Aβ) 42 in cerebrospinal fluid (CSF). The agreement between CSF Aβ42 measures from different immunoassays and visual PET readings may influence the use of CSF biomarkers and/or amyloid PET assessment in clinical practice and trials.To determine the concordance between CSF Aβ42 levels measured using 5 different immunoassays and visual amyloid PET analysis.The study included 262 patients with mild cognitive impairment or subjective cognitive decline from the Swedish BioFINDER (Biomarkers for Identifying Neurodegenerative Disorders Early and Reliably) cohort (recruited from September 1, 2010, through December 31, 2014) who had undergone flutemetamol F 18 ([18F]flutemetamol)-labeled PET. Levels of CSF Aβ42 were analyzed using the classic INNOTEST and the newer modified INNOTEST, fully automated Lumipulse (FL), EUROIMMUN (EI), and Meso Scale Discovery (MSD) assays. Concentrations of CSF Aβ were assessed using an antibody-independent mass spectrometry-based reference measurement procedure.The concordance of CSF Aβ42 levels and Aβ42:Aβ40 and Aβ42:tau ratios with visual [18F]flutemetamol PET status.Of 262 participants (mean [SD] age, 70.9 [5.5] years), 108 were women (41.2%) and 154 were men (58.8%). The mass spectrometry-derived Aβ42 values showed higher correlations with the modified Aβ42-INNOTEST (r=0.97), Aβ42-FL (r=0.93), Aβ42-EI (r=0.93), and Aβ42-MSD (r=0.95) assays compared with the classic Aβ42-INNOTEST assay (r=0.88; P≤.01). The signal in the classic Aβ42-INNOTEST assay was partly quenched by recombinant Aβ1-40 peptide. However, the classic Aβ42-INNOTEST assay showed better concordance with visual [18F]flutemetamol PET status (area under the receiver operating characteristic curve [AUC], 0.92) compared with the newer assays (AUCs, 0.87-0.89; P≤.01). The accuracies of the newer assays improved significantly when Aβ42:Aβ40 (AUCs, 0.93-0.95; P≤.01), Aβ42 to total tau (T-tau) (AUCs, 0.94; P≤.05), or Aβ42 to phosphorylated tau (P-tau) (AUCs, 0.94-0.95; P≤.001) ratios were used. A combination of the Aβ42:Aβ40 ratio and T-tau or P-tau level did not improve the accuracy compared with the ratio alone.Concentrations of CSF Aβ42 derived from the new immunoassays (modified INNOTEST, FL, EI, and MSD) may correlate better with the antibody-independent mass spectrometry-based reference measurement procedure and may show improved agreement with visual [18F]flutemetamol PET assessment when using the Aβ42:Aβ40 or Aβ42:tau ratios. These findings suggest the benefit of implementing the CSF Aβ42:Aβ40 or Aβ42:tau ratios as a biomarker of amyloid deposition in clinical practice and trials.
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11. |
- Janelidze, Shorena, et al.
(författare)
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CSF biomarkers of neuroinflammation and cerebrovascular dysfunction in early Alzheimer disease.
- 2018
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Ingår i: Neurology. - 1526-632X .- 0028-3878. ; 91:9
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Tidskriftsartikel (refereegranskat)abstract
- To measure CSF levels of biomarkers reflecting microglia and astrocytes activation, neuroinflammation, and cerebrovascular changes and study their associations with the core biomarkers of Alzheimer disease (AD) pathology (β-amyloid [Aβ] and tau), structural imaging correlates, and clinical disease progression over time.The study included cognitively unimpaired elderly (n = 508), patients with mild cognitive impairment (MCI, n = 256), and patients with AD dementia (n = 57) from the longitudinal Swedish BioFINDER cohort. CSF samples were analyzed for YKL-40, interleukin (IL)-6, IL-7, IL-8, IL-15, IP-10, monocyte chemoattractant protein 1, intercellular adhesion molecule 1 (ICAM-1), vascular adhesion molecule 1 (VCAM-1), placental growth factor, and fms-related tyrosine kinase 1 (Flt-1). MRI data were available from 677 study participants. Longitudinal clinical assessments were conducted in control individuals and patients with MCI (mean follow-up 3 years, range 1-6 years).CSF levels of YKL-40, ICAM-1, VCAM-1, IL-15, and Flt-1 were increased during the preclinical, prodromal, and dementia stages of AD. High levels of these biomarkers were associated with increased CSF levels of total tau, with the associations, especially for YKL-40, being stronger in Aβ-positive individuals. The results were similar for associations between phosphorylated tau and YKL-40, ICAM-1, and VCAM-1. High levels of the biomarkers were also associated with cortical thinning (primarily in the precuneus and superior parietal regions) and with subsequent cognitive deterioration in patients without dementia as measured with Mini-Mental State Examination (YKL-40) and Clinical Dementia Rating Sum of Boxes (YKL-40, ICAM-1, VCAM-1 and IL-15). Finally, higher levels of CSF YKL-40, ICAM-1, and Flt-1 increased risk of development of AD dementia in patients without dementia.Neuroinflammation and cerebrovascular dysfunction are early events occurring already at presymptomatic stages of AD and contribute to disease progression.
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12. |
- Janelidze, Shorena, et al.
(författare)
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Detecting amyloid positivity in early Alzheimer's disease using combinations of plasma A beta 42/A beta 40 and p-tau
- 2022
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Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 18:2, s. 283-293
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: We studied usefulness of combining blood amyloid beta A(beta)42/A beta 40, phosphorylated tau (p-tau)217, and neurofilament light (NfL) to detect abnormal brain A beta deposition in different stages of early Alzheimer's disease (AD). Methods: Plasma biomarkers were measured using mass spectrometry (A beta 42/A beta 40) and immunoassays (p-tau217 and NfL) in cognitively unimpaired individuals (CU, N = 591) and patients with mild cognitive impairment (MCI, N = 304) from two independent cohorts (BioFINDER-1, BioFINDER-2). Results: In CU, a combination of plasma A beta 42/A beta 40 and p-tau217 detected abnormal brain A beta status with area under the curve (AUC) of 0.83 to 0.86. In MCI, the models including p-tau217 alone or A beta 42/A beta 40 and p-tau217 had similar AUCs (0.86-0.88); however, the latter showed improved model fit. The models were implemented in an online application providing individualized risk assessments (https://brainapps.shinyappas.io/PredictAAbplasma/). Discussion:A combination of plasma A beta 42/A beta 40 and p-tau217 discriminated A beta status with relatively high accuracy, whereas p-tau217 showed strongest associations with A beta pathology in MCI but not in CU.
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13. |
- Janelidze, Shorena, et al.
(författare)
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Head-to-head comparison of 10 plasma phospho-tau assays in prodromal Alzheimer's disease.
- 2023
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Ingår i: Brain : a journal of neurology. - : Oxford University Press (OUP). - 1460-2156 .- 0006-8950. ; 146:4, s. 1592-1601
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Tidskriftsartikel (refereegranskat)abstract
- Plasma phospho-tau (p-tau) species have emerged as the most promising blood-based biomarkers of Alzheimer's disease. Here, we performed a head-to-head comparison of p-tau181, p-tau217 and p-tau231 measured using 10 assays to detect abnormal brain amyloid-β status and predict future progression to Alzheimer's dementia. The study included 135 patients with baseline diagnosis of mild cognitive impairment (mean age 72.4 years; 60.7% women) who were followed for an average of 4.9 years. Seventy-one participants had abnormal Aβ-status (i.e., abnormal CSF Aβ42/40) at baseline; and 45 of these Aβ-positive participants progressed to Alzheimer's dementia during follow-up. P-tau concentrations were determined in baseline plasma and CSF. P-tau217 and p-tau181 were both measured using immunoassays developed by Lilly Research Laboratories (Lilly) and mass spectrometry assays developed at Washington University (WashU). P-tau217 was also analysed using Simoa immunoassay developed by Janssen Research and Development (Janss). P-tau181 was measured using Simoa immunoassay from ADxNeurosciences (ADx), Lumipulse immunoassay from Fujirebio (Fuji) and Splex immunoassay from Mesoscale Discovery (Splex). Both p-tau181 and p-tau231 were quantified using Simoa immunoassay developed at the University of Gothenburg (UGOT). We found that the mass spectrometry-based p-tau217 (p-tau217WashU) exhibited significantly better performance than all other plasma p-tau biomarkers when detecting abnormal Aβ status (AUC=0.947; pdiff<0.015) or progression to Alzheimer's dementia (AUC=0.932; pdiff<0.027). Among immunoassays, p-tau217Lilly had the highest AUCs (0.886-0.889), which was not significantly different from the AUCs of p-tau217Janss, p-tau181ADx and p-tau181WashU (AUCrange, 0.835-0.872; pdiff>0.09), but higher compared with AUC of p-tau231UGOT, p-tau181Lilly, p-tau181UGOT, p-tau181Fuji, and p-tau181Splex (AUCrange, 0.642-0.813; pdiff ≤0.029). Correlations between plasma and CSF values were strongest for p-tau217WashU (R=0.891) followed by p-tau217Lilly (R=0.755; pdiff=0.003 vs p-tau217WashU) and weak to moderate for the rest of the p-tau biomarkers (Rrange, 0.320-0.669). In conclusion, the findings suggest that among all tested plasma p-tau assays, mass spectrometry-based measures of p-tau217 perform best when identifying mild cognitive impairment patients with abnormal brain Aβ or those who will subsequently progress to Alzheimer's dementia. Several other assays (p-tau217Lilly, p-tau217Janss, p-tau181ADx, and p-tau181WashU) showed relatively high and consistent accuracy across both outcomes. The results further indicate that the highest performing assays have performance metrics that rival the gold standards of Aβ-PET and CSF. If further validated, our findings will have significant impacts in diagnosis, screening and treatment for Alzheimer's dementia in the future.
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14. |
- Janelidze, Shorena, et al.
(författare)
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Increased blood-brain barrier permeability is associated with dementia and diabetes but not amyloid pathology or APOE genotype
- 2017
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 51, s. 104-112
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Tidskriftsartikel (refereegranskat)abstract
- Blood-brain barrier (BBB) dysfunction might be an important component of many neurodegenerative disorders. In this study, we investigated its role in dementia using large clinical cohorts. The cerebrospinal fluid (CSF)/plasma albumin ratio (Qalb), an indicator of BBB (and blood-CSF barrier) permeability, was measured in a total of 1015 individuals. The ratio was increased in patients with Alzheimer's disease, dementia with Lewy bodies or Parkinson's disease dementia, subcortical vascular dementia, and frontotemporal dementia compared with controls. However, this measure was not changed during preclinical or prodromal Alzheimer's disease and was not associated with amyloid positron emission tomography or APOE genotype. The Qalb was increased in diabetes mellitus and correlated positively with CSF bio-markers of angiogenesis and endothelial dysfunction (vascular endothelial growth factor, intracellular adhesion molecule 1, and vascular cell adhesion molecule 1). In healthy elderly, high body mass index and waist-hip ratio predicted increased Qalb 20 years later. In summary, BBB permeability is increased in major dementia disorders but does not relate to amyloid pathology or APOE genotype. Instead, BBB impairment may be associated with diabetes and brain microvascular damage. (C) 2016 The Authors. Published by Elsevier Inc.
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15. |
- Janelidze, Shorena, et al.
(författare)
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Increased CSF biomarkers of angiogenesis in Parkinson disease
- 2015
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Ingår i: Neurology. - 0028-3878 .- 1526-632X. ; 85:21, s. 1834-1842
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Tidskriftsartikel (refereegranskat)abstract
- To study biomarkers of angiogenesis in Parkinson disease (PD), and how these are associated with clinical characteristics, blood-brain barrier (BBB) permeability, and cerebrovascular disease.
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16. |
- Janelidze, Shorena, et al.
(författare)
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Plasma beta-amyloid in Alzheimer's disease and vascular disease
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Implementation of amyloid biomarkers in clinical practice would be accelerated if such biomarkers could be measured in blood. We analyzed plasma levels of A beta 42 and A beta 40 in a cohort of 719 individuals (the Swedish BioFINDER study), including patients with subjective cognitive decline (SCD), mild cognitive impairment (MCI), Alzheimer's disease (AD) dementia and cognitively healthy elderly, using a ultrasensitive immunoassay (Simoa platform). There were weak positive correlations between plasma and cerebrospinal fluid (CSF) levels for both A beta 42 and A beta 40, and negative correlations between plasma A beta 42 and neocortical amyloid deposition (measured with PET). Plasma levels of A beta 42 and A beta 40 were reduced in AD dementia compared with all other diagnostic groups. However, during the preclinical or prodromal AD stages (i.e. in amyloid positive controls, SCD and MCI) plasma concentration of A beta 42 was just moderately decreased whereas A beta 40 levels were unchanged. Higher plasma (but not CSF) levels of A beta were associated with white matter lesions, cerebral microbleeds, hypertension, diabetes and ischemic heart disease. In summary, plasma A beta is overtly decreased during the dementia stage of AD indicating that prominent changes in A beta metabolism occur later in the periphery compared to the brain. Further, increased levels of A beta in plasma are associated with vascular disease.
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17. |
- Janelidze, Shorena, et al.
(författare)
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Plasma P-tau181 in Alzheimer's disease: relationship to other biomarkers, differential diagnosis, neuropathology and longitudinal progression to Alzheimer's dementia
- 2020
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 26, s. 379-386
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Tidskriftsartikel (refereegranskat)abstract
- Plasma phosphorylated tau181 (P-tau181) might be increased in Alzheimer's disease (AD), but its usefulness for differential diagnosis and prognosis is unclear. We studied plasma P-tau181 in three cohorts, with a total of 589 individuals, including cognitively unimpaired participants and patients with mild cognitive impairment (MCI), AD dementia and non-AD neurodegenerative diseases. Plasma P-tau181 was increased in preclinical AD and further increased at the MCI and dementia stages. It correlated with CSF P-tau181 and predicted positive Tau positron emission tomography (PET) scans (area under the curve (AUC) = 0.87-0.91 for different brain regions). Plasma P-tau181 differentiated AD dementia from non-AD neurodegenerative diseases with an accuracy similar to that of Tau PET and CSF P-tau181 (AUC = 0.94-0.98), and detected AD neuropathology in an autopsy-confirmed cohort. High plasma P-tau181 was associated with subsequent development of AD dementia in cognitively unimpaired and MCI subjects. In conclusion, plasma P-tau181 is a noninvasive diagnostic and prognostic biomarker of AD, which may be useful in clinical practice and trials. Plasma P-tau18 level increased with progression of Alzheimer's disease (AD) and differentiated AD dementia from other neurodegenerative diseases, supporting its further development as a blood-based biomarker for AD.
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18. |
- Karikari, Thomas, et al.
(författare)
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Blood phosphorylated tau 181 as a biomarker for Alzheimer's disease: a diagnostic performance and prediction modelling study using data from four prospective cohorts.
- 2020
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Ingår i: The Lancet. Neurology. - 1474-4465 .- 1474-4422. ; 19:5, s. 422-433
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Tidskriftsartikel (refereegranskat)abstract
- CSF and PET biomarkers of amyloid β and tau accurately detect Alzheimer's disease pathology, but the invasiveness, high cost, and poor availability of these detection methods restrict their widespread use as clinical diagnostic tools. CSF tau phosphorylated at threonine 181 (p-tau181) is a highly specific biomarker for Alzheimer's disease pathology. We aimed to assess whether blood p-tau181 could be used as a biomarker for Alzheimer's disease and for prediction of cognitive decline and hippocampal atrophy.We developed and validated an ultrasensitive blood immunoassay for p-tau181. Assay performance was evaluated in four clinic-based prospective cohorts. The discovery cohort comprised patients with Alzheimer's disease and age-matched controls. Two validation cohorts (TRIAD and BioFINDER-2) included cognitively unimpaired older adults (mean age 63-69 years), participants with mild cognitive impairment (MCI), Alzheimer's disease, and frontotemporal dementia. In addition, TRIAD included healthy young adults (mean age 23 years) and BioFINDER-2 included patients with other neurodegenerative disorders. The primary care cohort, which recruited participants in Montreal, Canada, comprised control participants from the community without a diagnosis of a neurological condition and patients referred from primary care physicians of the Canadian National Health Service for specialist care. Concentrations of plasma p-tau181 were compared with established CSF and PET biomarkers and longitudinal measurements using Spearman correlation, area under the curve (AUC), and linear regression analyses.We studied 37 individuals in the discovery cohort, 226 in the first validation cohort (TRIAD), 763 in the second validation cohort (BioFINDER-2), and 105 in the primary care cohort (n=1131 individuals). In all cohorts, plasma p-tau181 showed gradual increases along the Alzheimer's disease continuum, from the lowest concentrations in amyloid β-negative young adults and cognitively unimpaired older adults, through higher concentrations in the amyloid β-positive cognitively unimpaired older adults and MCI groups, to the highest concentrations in the amyloid β-positive MCI and Alzheimer's disease groups (p<0·001, Alzheimer's disease vs all other groups). Plasma p-tau181 distinguished Alzheimer's disease dementia from amyloid β-negative young adults (AUC=99·40%) and cognitively unimpaired older adults (AUC=90·21-98·24% across cohorts), as well as other neurodegenerative disorders, including frontotemporal dementia (AUC=82·76-100% across cohorts), vascular dementia (AUC=92·13%), progressive supranuclear palsy or corticobasal syndrome (AUC=88·47%), and Parkinson's disease or multiple systems atrophy (AUC=81·90%). Plasma p-tau181 was associated with PET-measured cerebral tau (AUC=83·08-93·11% across cohorts) and amyloid β (AUC=76·14-88·09% across cohorts) pathologies, and 1-year cognitive decline (p=0·0015) and hippocampal atrophy (p=0·015). In the primary care cohort, plasma p-tau181 discriminated Alzheimer's disease from young adults (AUC=100%) and cognitively unimpaired older adults (AUC=84·44%), but not from MCI (AUC=55·00%).Blood p-tau181 can predict tau and amyloid β pathologies, differentiate Alzheimer's disease from other neurodegenerative disorders, and identify Alzheimer's disease across the clinical continuum. Blood p-tau181 could be used as a simple, accessible, and scalable test for screening and diagnosis of Alzheimer's disease.Alzheimer Drug Discovery Foundation, European Research Council, Swedish Research Council, Swedish Alzheimer Foundation, Swedish Dementia Foundation, Alzheimer Society Research Program.
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19. |
- Karlsson, Linda, et al.
(författare)
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Cerebrospinal fluid reference proteins increase accuracy and interpretability of biomarkers for brain diseases.
- 2024
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Ingår i: Nature Communications. - 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Cerebrospinal fluid (CSF) biomarkers reflect brain pathophysiology and are used extensively in translational research as well as in clinical practice for diagnosis of neurological diseases, e.g., Alzheimer's disease (AD). However, CSF biomarker concentrations may be influenced by non-disease related inter-individual variability. Here we use a data-driven approach to demonstrate the existence of inter-individual variability in mean standardized CSF protein levels. We show that these non-disease related differences cause many commonly reported CSF biomarkers to be highly correlated, thereby producing misleading results if not accounted for. To adjust for this inter-individual variability, we identified and evaluated high-performing reference proteins which improved the diagnostic accuracy of key CSF AD biomarkers. Our reference protein method attenuates the risk for false positive findings, and improves the sensitivity and specificity of CSF biomarkers, with broad implications for both research and clinical practice.
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20. |
- Lantero Rodriguez, Juan, et al.
(författare)
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Plasma N-terminal containing tau fragments (NTA-tau): a biomarker of tau deposition in Alzheimer's Disease
- 2024
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Ingår i: MOLECULAR NEURODEGENERATION. - 1750-1326. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Novel phosphorylated-tau (p-tau) blood biomarkers (e.g., p-tau181, p-tau217 or p-tau231), are highly specific for Alzheimer's disease (AD), and can track amyloid-beta (A beta) and tau pathology. However, because these biomarkers are strongly associated with the emergence of A beta pathology, it is difficult to determine the contribution of insoluble tau aggregates to the plasma p-tau signal in blood. Therefore, there remains a need for a biomarker capable of specifically tracking insoluble tau accumulation in brain. Methods NTA is a novel ultrasensitive assay targeting N-terminal containing tau fragments (NTA-tau) in cerebrospinal fluid (CSF) and plasma, which is elevated in AD. Using two well-characterized research cohorts (BioFINDER-2, n = 1,294, and BioFINDER-1, n = 932), we investigated the association between plasma NTA-tau levels and disease progression in AD, including tau accumulation, brain atrophy and cognitive decline. Results We demonstrate that plasma NTA-tau increases across the AD continuum, especially during late stages, and displays a moderate-to-strong association with tau-PET (beta = 0.54, p < 0.001) in A beta-positive participants, while weak with A beta-PET (beta = 0.28, p < 0.001). Unlike plasma p-tau181, GFAP, NfL and t-tau, tau pathology determined with tau-PET is the most prominent contributor to NTA-tau variance (52.5% of total R-2), while having very low contribution from A beta pathology measured with CSF A beta 42/40 (4.3%). High baseline NTA-tau levels are predictive of tau-PET accumulation (R-2 = 0.27), steeper atrophy (R-2 >= 0.18) and steeper cognitive decline (R-2 >= 0.27) in participants within the AD continuum. Plasma NTA-tau levels significantly increase over time in A beta positive cognitively unimpaired (beta(std) = 0.16) and impaired (beta(std) = 0.18) at baseline compared to their A beta negative counterparts. Finally, longitudinal increases in plasma NTA-tau levels were associated with steeper longitudinal decreases in cortical thickness (R-2 = 0.21) and cognition (R-2 = 0.20). Conclusion Our results indicate that plasma NTA-tau levels increase across the AD continuum, especially during mid-to-late AD stages, and it is closely associated with in vivo tau tangle deposition in AD and its downstream effects. Moreover, this novel biomarker has potential as a cost-effective and easily accessible tool for monitoring disease progression and cognitive decline in clinical settings, and as an outcome measure in clinical trials which also need to assess the downstream effects of successful A beta removal.
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21. |
- Mattsson-Carlgren, Niklas, et al.
(författare)
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A beta deposition is associated with increases in soluble and phosphorylated tau that precede a positive Tau PET in Alzheimer's disease
- 2020
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 6:16
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Tidskriftsartikel (refereegranskat)abstract
- The links between beta-amyloid ( A beta ) and tau in Alzheimer's disease are unclear. Cognitively unimpaired persons with signs of A beta pathology had increased cerebrospinal fluid (CSF) phosphorylated tau (P-tau181 and P-tau217) and total-tau (T-tau), which increased over time, despite no detection of insoluble tau aggregates [normal Tau positron emission tomography (PET)]. CSF P-tau and T-tau started to increase before the threshold for Amyloid PET positivity, while Tau PET started to increase after Amyloid PET positivity. Effects of Amyloid PET on Tau PET were mediated by CSF P-tau, and high CSF P-tau predicted increased Tau PET rates. Individuals with MAPT mutations and signs of tau deposition (but without A beta pathology) had normal CSF P-tau levels. In 5xFAD mice, CSF tau increased when A beta aggregation started. These results show that A beta pathology may induce changes in soluble tau release and phosphorylation, which is followed by tau aggregation several years later in humans.
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22. |
- Mattsson-Carlgren, Niklas, et al.
(författare)
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Plasma Biomarker Strategy for Selecting Patients With Alzheimer Disease for Antiamyloid Immunotherapies
- 2024
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Ingår i: JAMA neurology. - 2168-6157 .- 2168-6149. ; 81:1, s. 69-78
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Tidskriftsartikel (refereegranskat)abstract
- Antiamyloid immunotherapies against Alzheimer disease (AD) are emerging. Scalable, cost-effective tools will be needed to identify amyloid β (Aβ)-positive patients without an advanced stage of tau pathology who are most likely to benefit from these therapies. Blood-based biomarkers might reduce the need to use cerebrospinal fluid (CSF) or positron emission tomography (PET) for this.To evaluate plasma biomarkers for identifying Aβ positivity and stage of tau accumulation.The cohort study (BioFINDER-2) was a prospective memory-clinic and population-based study. Participants with cognitive concerns were recruited from 2017 to 2022 and divided into a training set (80% of the data) and test set (20%).Baseline values for plasma phosphorylated tau 181 (p-tau181), p-tau217, p-tau231, N-terminal tau, glial fibrillary acidic protein, and neurofilament light chain.Performance to classify participants by Aβ status (defined by Aβ-PET or CSF Aβ42/40) and tau status (tau PET). Number of hypothetically saved PET scans in a plasma biomarker-guided workflow.Of a total 912 participants, there were 499 males (54.7%) and 413 females (45.3%), and the mean (SD) age was 71.1 (8.49) years. Among the biomarkers, plasma p-tau217 was most strongly associated with Aβ positivity (test-set area under the receiver operating characteristic curve [AUC]=0.94; 95% CI, 0.90-0.97). A 2-cut-point procedure was evaluated, where only participants with ambiguous plasma p-tau217 values (17.1% of the participants in the test set) underwent CSF or PET to assign definitive Aβ status. This procedure had an overall sensitivity of 0.94 (95% CI, 0.90-0.98) and a specificity of 0.86 (95% CI, 0.77-0.95). Next, plasma biomarkers were used to differentiate low-intermediate vs high tau-PET load among Aβ-positive participants. Plasma p-tau217 again performed best, with the test AUC=0.92 (95% CI, 0.86-0.97), without significant improvement when adding any of the other plasma biomarkers. At a false-negative rate less than 10%, the use of plasma p-tau217 could avoid 56.9% of tau-PET scans needed to identify high tau PET among Aβ-positive participants. The results were validated in an independent cohort (n=118).This study found that algorithms using plasma p-tau217 can accurately identify most Aβ-positive individuals, including those likely to have a high tau load who would require confirmatory tau-PET imaging. Plasma p-tau217 measurements may substantially reduce the number of invasive and costly confirmatory tests required to identify individuals who would likely benefit from antiamyloid therapies.
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23. |
- Mattsson-Carlgren, Niklas, et al.
(författare)
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Prediction of Longitudinal Cognitive Decline in Preclinical Alzheimer Disease Using Plasma Biomarkers
- 2023
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Ingår i: Jama Neurology. - : American Medical Association (AMA). - 2168-6149. ; 80:4, s. 360-369
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Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE Alzheimer disease (AD) pathology starts with a prolonged phase of beta-amyloid (A beta) accumulation without symptoms. The duration of this phase differs greatly among individuals. While this disease phase has high relevance for clinical trial designs, it is currently unclear how to best predict the onset of clinical progression.OBJECTIVE To evaluate combinations of different plasma biomarkers for predicting cognitive decline in A beta-positive cognitively unimpaired (CU) individuals.DESIGN, SETTING, AND PARTICIPANTS This prospective population-based prognostic study evaluated data from 2 prospective longitudinal cohort studies (the Swedish BioFINDER-1 and the Wisconsin Registry for Alzheimer Prevention [WRAP]), with data collected from February 8, 2010, to October 21, 2020, for the BioFINDER-1 cohort and from August 11, 2011, to June 27, 2021, for the WRAP cohort. Participants were CU individuals recruited from memory clinics who had brain A beta pathology defined by cerebrospinal fluid (CSF) A beta 42/40 in the BioFINDER-1 study and by Pittsburgh Compound B (PiB) positron emission tomography (PET) in the WRAP study. A total of 564 eligible A beta-positive and A beta-negative CU participants with available relevant data from the BioFINDER-1 and WRAP cohorts were included in the study; of those, 171 A beta-positive participants were included in the main analyses.EXPOSURES Baseline P-tau181, P-tau217, P-tau231, glial fibrillary filament protein, and neurofilament light measured in plasma; CSF biomarkers in the BioFINDER-1 cohort, and PiB PET uptake in the WRAP cohort.MAIN OUTCOMES AND MEASURES The primary outcome was longitudinal measures of cognition (using the Mini-Mental State Examination [MMSE] and the modified Preclinical Alzheimer Cognitive Composite [mPACC]) over a median of 6 years (range, 2-10 years). The secondary outcome was conversion to AD dementia. Baseline biomarkers were used in linear regression models to predict rates of longitudinal cognitive change (calculated separately). Models were adjusted for age, sex, years of education, apolipoprotein E epsilon 4 allele status, and baseline cognition. Multivariable models were compared based on model R-2 coefficients and corrected Akaike information criterion.RESULTS Among 171 A beta-positive CU participants included in the main analyses, 119 (mean [SD] age, 73.0 [5.4] years; 60.5% female) were from the BioFINDER-1 study, and 52 (mean [SD] age, 64.4 [4.6] years; 65.4% female) were from the WRAP study. In the BioFINDER-1 cohort, plasma P-tau217 was the best marker to predict cognitive decline in the mPACC (model R-2 = 0.41) and the MMSE (model R-2 = 0.34) and was superior to the covariates-only models (mPACC: R-2 = 0.23; MMSE: R-2 = 0.04; P < .001 for both comparisons). Results were validated in the WRAP cohort; for example, plasma P-tau217 was associated with mPACC slopes (R-2 = 0.13 vs 0.01 in the covariates-only model; P = .01) and MMSE slopes (R-2 = 0.29 vs 0.24 in the covariates-only model; P = .046). Sparse models were identified with plasma P-tau217 as a predictor of cognitive decline. Power calculations for enrichment in hypothetical clinical trials revealed large relative reductions in sample sizes when using plasma P-tau217 to enrich for CU individuals likely to experience cognitive decline over time.CONCLUSIONS AND RELEVANCE In this study, plasma P-tau217 predicted cognitive decline in patients with preclinical AD. These findings suggest that plasma P-tau217 may be used as a complement to CSF or PET for participant selection in clinical trials of novel disease-modifying treatments.
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24. |
- Mendes, Augusto J., et al.
(författare)
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Head-to-head study of diagnostic accuracy of plasma and cerebrospinal fluid p-tau217 versus p-tau181 and p-tau231 in a memory clinic cohort
- 2024
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Ingår i: JOURNAL OF NEUROLOGY. - 0340-5354 .- 1432-1459.
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Tidskriftsartikel (refereegranskat)abstract
- Background and objective Phosphorylated tau (p-tau) 217 has recently received attention because it seems more reliable than other p-tau variants for identifying Alzheimer's disease (AD) pathology. Thus, we aimed to compare the diagnostic accuracy of plasma and CSF p-tau217 with p-tau181 and p-tau231 in a memory clinic cohort.Methods The study included 114 participants (CU = 33; MCI = 67; Dementia = 14). The p-tau variants were correlated versus continuous measures of amyloid (A) and tau (T)-PET. The p-tau phospho-epitopes were assessed through: (i) effect sizes (delta) between diagnostic and A +/- and T +/- groups; (ii) receiver operating characteristic (ROC) analyses in A-PET and T-PET.Results The correlations between both plasma and CSF p-tau217 with A-PET and T-PET (r range 0.64-0.83) were stronger than those of p-tau181 (r range 0.44-0.79) and p-tau231 (r range 0.46-0.76). Plasma p-tau217 showed significantly higher diagnostic accuracy than p-tau181 and p-tau231 in (i) differences between diagnostic and biomarker groups (delta(range): p-tau217 = 0.55-0.96; p-tau181 = 0.51-0.67; p-tau231 = 0.53-0.71); (ii) ROC curves to identify A-PET and T-PET positivity (AUC(average): p-tau217 = 0.96; p-tau181 = 0.76; p-tau231 = 0.79). On the other hand, CSF p-tau217 (AUC(average) = 0.95) did not reveal significant differences in A-PET and T-PET AUC than p-tau181 (AUC(average) = 0.88) and p-tau231 (AUC(average) = 0.89).Discussion Plasma p-tau217 demonstrated better performance in the identification of AD pathology and clinical phenotypes in comparison with other variants of p-tau in a memory clinic cohort. Furthermore, p-tau217 had comparable performance in plasma and CSF. Our findings suggest the potential of plasma p-tau217 in the diagnosis and screening for AD, which could allow for a decreased use of invasive biomarkers in the future.
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25. |
- Minta, Karolina, et al.
(författare)
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Cerebrospinal fluid concentrations of extracellular matrix proteins in Alzheimer's disease
- 2019
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877. ; 69:4, s. 1213-1220
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Tidskriftsartikel (refereegranskat)abstract
- Background: Brevican, neurocan, tenascin-C, and tenascin-R are extracellular matrix (ECM) proteins that are mainly expressed in the brain. They play important roles in proliferation and migration of neurons and other cell types in the brain. These ECM proteins may also be involved in various pathologies, including reactive gliosis. Objective: The aim of the study was to investigate if ECM protein concentrations in cerebrospinal fluid (CSF) are linked to the neurodegenerative process in Alzheimer's disease (AD). Methods: Lumbar CSF samples from a non-AD control group (n = 50) and a clinically diagnosedADgroup (n = 42), matched for age and gender, were analyzed using commercially available ELISAs detecting ECM proteins. Mann-Whitney U test was used to examine group differences, while Spearman's rho test was used for correlations. Results: Brevican, neurocan, tenascin-R, and tenascin-C concentrations in AD patients did not differ compared to healthy controls or when the groups were dichotomized based on the Aβ42/40 cut-off. CSF tenascin-C and tenascin-R concentrations were significantly higher in women than in men in the AD group (p = 0.02). Conclusion: ECM proteins do not reflect AD-pathology in CSF. CSF tenascin-C and tenascin-R upregulation in women possibly reveal sexual dimorphism in the central nervous system immunity during AD. © 2019 - IOS Press and the authors. All rights reserved.
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26. |
- Nilsson, Johanna, 1993, et al.
(författare)
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Cerebrospinal fluid biomarker panel for synaptic dysfunction in a broad spectrum of neurodegenerative diseases.
- 2024
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Ingår i: Brain : a journal of neurology. - 1460-2156.
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Tidskriftsartikel (refereegranskat)abstract
- Synaptic dysfunction and degeneration is likely the key pathophysiology for the progression of cognitive decline in various dementia disorders. Synaptic status can be monitored by measurement of synaptic proteins in cerebrospinal fluid (CSF). In the current study, the aim was to investigate and compare both known and new synaptic proteins as potential biomarkers of synaptic dysfunction, especially in the context of Alzheimer's disease (AD). Seventeen synaptic proteins were quantified in CSF using two different targeted mass spectrometry assays in the prospective Swedish BioFINDER-2 study. The study included 958 individuals, characterized as having mild cognitive impairment (MCI, n=205), AD dementia (n=149), and a spectrum of other neurodegenerative diseases (n=171), as well as cognitively unimpaired (CU, n=443). Synaptic protein levels were compared between diagnostic groups and their associations with cognitive decline and key neuroimaging measures (Aβ-PET, tau-PET, and cortical thickness) were assessed. Among the 17 synaptic proteins examined, 14 were specifically elevated in the AD continuum. SNAP-25, 14-3-3 zeta/delta, beta-synuclein, and neurogranin exhibited the highest discriminatory accuracy to differentiate AD dementia from controls (AUCs=0.81-0.93). SNAP-25 and 14-3-3 zeta/delta also had the strongest associations with tau-PET, Aβ-PET, and cortical thickness at baseline, and were associated with longitudinal changes in these imaging biomarkers (β(SE)=-0.056(0.0006) to 0.058(0.005), p<0.0001). SNAP-25 was the strongest predictor of progression to AD dementia in non-demented individuals (Hazard ratio=2.11). In contrast, neuronal pentraxins were decreased in all neurodegenerative diseases (except for Parkinson's disease), and NPTX2 showed the strongest associations with subsequent cognitive decline (longitudinal MMSE; β(SE)=0.57(0.1), p≤0.0001 and mPACC; β(SE)=0.095(0.024), p≤0.001) across the AD continuum. Interestingly, utilizing a ratio of the proteins that displayed higher levels in AD, such as SNAP-25 or 14-3-3 zeta/delta, over NPTX2 improved the biomarkers' association with cognitive decline and brain atrophy. We found that especially 14-3-3 zeta/delta and SNAP-25 are promising synaptic biomarkers of pathophysiological changes in AD. Neuronal pentraxins were identified as general indicators of neurodegeneration and associated with cognitive decline across various neurodegenerative dementias. The ratios of SNAP-25/NPTX2 and 14-3-3 zeta/delta/NPTX2 were found to best predict cognitive decline and brain atrophy.
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27. |
- Orduña Dolado, Anna, et al.
(författare)
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Effects of time of the day at sampling on CSF and plasma levels of Alzheimer' disease biomarkers
- 2024
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Ingår i: ALZHEIMERS RESEARCH & THERAPY. - 1758-9193. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Studies suggest that cerebrospinal fluid (CSF) levels of amyloid-beta (A beta)42 and A beta 40 present a circadian rhythm. However sustained sampling of large volumes of CSF with indwelling intrathecal catheters used in most of these studies might have affected CSF dynamics and thereby confounded the observed fluctuations in the biomarker levels. Methods We included 38 individuals with either normal (N = 20) or abnormal (N = 18) CSF A beta 42/A beta 40 levels at baseline. CSF and plasma were collected at two visits separated by an average of 53 days with lumbar punctures and venipunctures performed either in the morning or evening. At the first visit, sample collection was performed in the morning for 17 participants and the order was reversed for the remaining 21 participants. CSF and plasma samples were analyzed for Alzheimer' disease (AD) biomarkers, including A beta 42, A beta 40, GFAP, NfL p-tau181, p-tau217, p-tau231 and t-tau. CSF samples were also tested using mass spectrometry for 22 synaptic and endo-lysosomal proteins. Results CSF A beta 42 (mean difference [MD], 0.21 ng/mL; p = 0.038), CSF A beta 40 (MD, 1.85 ng/mL; p < 0.001), plasma A beta 42 (MD, 1.65 pg/mL; p = 0.002) and plasma A beta 40 (MD, 0.01 ng/mL, p = 0.002) were increased by 4.2-17.0% in evening compared with morning samples. Further, CSF levels of 14 synaptic and endo-lysosomal proteins, including neurogranin and neuronal pentraxin-1, were increased by 4.5-13.3% in the evening samples (MDrange, 0.02-0.56 fmol/l; p < 0.042). However, no significant differences were found between morning and evening levels for the A beta 42/A beta 40 ratio, different p-tau variants, GFAP and NfL. There were no significant interaction between sampling time and A beta status for any of the biomarkers, except that CSF t-tau was increased (by 5.74%) in the evening samples compared to the morning samples in A beta-positive (MD, 16.46 ng/ml; p = 0.009) but not A beta-negative participants (MD, 1.89 ng/ml; p = 0.47). There were no significant interactions between sampling time and order in which samples were obtained. Discussion Our findings provide evidence for diurnal fluctuations in A beta peptide levels, both in CSF and plasma, while CSF and plasma p-tau, GFAP and NfL were unaffected. Importantly, A beta 42/A beta 40 ratio remained unaltered, suggesting that it is more suitable for implementation in clinical workup than individual A beta peptides. Additionally, we show that CSF levels of many synaptic and endo-lysosomal proteins presented a diurnal rhythm, implying a build-up of neuronal activity markers during the day. These results will guide the development of unified sample collection procedures to avoid effects of diurnal variation for future implementation of AD biomarkers in clinical practice and drug trials.
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28. |
- Ossenkoppele, Rik, et al.
(författare)
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Tau PET correlates with different Alzheimer’s disease-related features compared to CSF and plasma p-tau biomarkers
- 2021
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Ingår i: EMBO Molecular Medicine. - : EMBO. - 1757-4676 .- 1757-4684. ; 13:8
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Tidskriftsartikel (refereegranskat)abstract
- PET, CSF and plasma biomarkers of tau pathology may be differentially associated with Alzheimer's disease (AD)-related demographic, cognitive, genetic and neuroimaging markers. We examined 771 participants with normal cognition, mild cognitive impairment or dementia from BioFINDER-2 (n=400) and ADNI (n=371). All had tau-PET ([18F]RO948 in BioFINDER-2, [18F]flortaucipir in ADNI) and CSF p-tau181 biomarkers available. Plasma p-tau181 and plasma/CSF p-tau217 were available in BioFINDER-2 only. Concordance between PET, CSF and plasma tau biomarkers ranged between 66 and 95%. Across the whole group, ridge regression models showed that increased CSF and plasma p-tau181 and p-tau217 levels were independently of tau PET associated with higher age, and APOEɛ4-carriership and Aβ-positivity, while increased tau-PET signal in the temporal cortex was associated withworse cognitive performance and reduced cortical thickness. We conclude that biofluid and neuroimaging markers of tau pathology convey partly independent information, with CSF and plasma p-tau181 and p-tau217 levels being more tightly linked with early markers of AD (especially Aβ-pathology), while tau-PET shows the strongest associations with cognitive and neurodegenerative markers of disease progression.
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29. |
- Palmqvist, Sebastian, et al.
(författare)
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An accurate fully automated panel of plasma biomarkers for Alzheimer's disease
- 2023
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Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 19:4, s. 1204-1215
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Tidskriftsartikel (refereegranskat)abstract
- Introduction There is a great need for fully automated plasma assays that can measure amyloid beta (A beta) pathology and predict future Alzheimer's disease (AD) dementia. Methods Two cohorts (n = 920) were examined: Panel A+ (n = 32 cognitively unimpaired [CU], n = 106 mild cognitive impairment [MCI], and n = 89 AD) and BioFINDER-1 (n = 461 CU, n = 232 MCI). Plasma A beta 42/A beta 40, phosphorylated tau (p-tau)181, two p-tau217 variants, ApoE4 protein, neurofilament light, and GFAP were measured using Elecsys prototype immunoassays. Results The best biomarker for discriminating A beta-positive versus A beta-negative participants was A beta 42/A beta 40 (are under the curve [AUC] 0.83-0.87). Combining A beta 42/A beta 40, p-tau181, and ApoE4 improved the AUCs significantly (0.90 to 0.93; P< 0.01). Adding additional biomarkers had marginal effects (Delta AUC <= 0.01). In BioFINDER, p-tau181, p-tau217, and ApoE4 predicted AD dementia within 6 years in CU (AUC 0.88) and p-tau181, p-tau217, and A beta 42/A beta 40 in MCI (AUC 0.87). Discussion The high accuracies for A beta pathology and future AD dementia using fully automated instruments are promising for implementing plasma biomarkers in clinical trials and clinical routine.
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30. |
- Palmqvist, Sebastian, et al.
(författare)
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Cerebrospinal fluid and plasma biomarker trajectories with increasing amyloid deposition in Alzheimer's disease
- 2019
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Ingår i: Embo Molecular Medicine. - : EMBO. - 1757-4676 .- 1757-4684. ; 11:12
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Tidskriftsartikel (refereegranskat)abstract
- Failures in Alzheimer's disease (AD) drug trials highlight the need to further explore disease mechanisms and alterations of biomarkers during the development of AD. Using cross-sectional data from 377 participants in the BioFINDER study, we examined seven cerebrospinal fluid (CSF) and six plasma biomarkers in relation to beta-amyloid (A beta) PET uptake to understand their evolution during AD. In CSF, A beta 42 changed first, closely followed by A beta 42/A beta 40, phosphorylated-tau (P-tau), and total-tau (T-tau). CSF neurogranin, YKL-40, and neurofilament light increased after the point of A beta PET positivity. The findings were replicated using A beta 42, A beta 40, P-tau, and T-tau assays from five different manufacturers. Changes were seen approximately simultaneously for CSF and plasma biomarkers. Overall, plasma biomarkers had smaller dynamic ranges, except for CSF and plasma P-tau which were similar. In conclusion, using state-of-the-art biomarkers, we identified the first changes in A beta, closely followed by soluble tau. Only after A beta PET became abnormal, biomarkers of neuroinflammation, synaptic dysfunction, and neurodegeneration were altered. These findings lend in vivo support of the amyloid cascade hypotheses in humans.
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31. |
- Palmqvist, Sebastian, et al.
(författare)
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Discriminative Accuracy of Plasma Phospho-tau217 for Alzheimer Disease vs Other Neurodegenerative Disorders
- 2020
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Ingår i: Jama-Journal of the American Medical Association. - : American Medical Association (AMA). - 0098-7484. ; 324:8, s. 772-781
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Tidskriftsartikel (refereegranskat)abstract
- Key PointsQuestionWhat is the discriminative accuracy of plasma phospho-tau217 (P-tau217) for differentiating Alzheimer disease from other neurodegenerative disorders? FindingsIn this cross-sectional study that included 1402 participants from 3 selected cohorts, plasma P-tau217 discriminated Alzheimer disease from other neurodegenerative diseases (area under the receiver operating characteristic curve of 0.89 in a neuropathologically defined cohort and 0.96 in a clinically defined cohort), with performance that was significantly better than established Alzheimer disease plasma- and MRI-based biomarkers but not significantly different from key CSF- or PET-based biomarkers. MeaningAlthough plasma P-tau217 was able to discriminate Alzheimer disease from other neurodegenerative diseases, further research is needed to validate the findings in unselected and diverse populations, optimize the assay, and determine its potential role in clinical care. ImportanceThere are limitations in current diagnostic testing approaches for Alzheimer disease (AD). ObjectiveTo examine plasma tau phosphorylated at threonine 217 (P-tau217) as a diagnostic biomarker for AD. Design, Setting, and ParticipantsThree cross-sectional cohorts: an Arizona-based neuropathology cohort (cohort 1), including 34 participants with AD and 47 without AD (dates of enrollment, May 2007-January 2019); the Swedish BioFINDER-2 cohort (cohort 2), including cognitively unimpaired participants (n=301) and clinically diagnosed patients with mild cognitive impairment (MCI) (n=178), AD dementia (n=121), and other neurodegenerative diseases (n=99) (April 2017-September 2019); and a Colombian autosomal-dominant AD kindred (cohort 3), including 365 PSEN1 E280A mutation carriers and 257 mutation noncarriers (December 2013-February 2017). ExposuresPlasma P-tau217. Main Outcomes and MeasuresPrimary outcome was the discriminative accuracy of plasma P-tau217 for AD (clinical or neuropathological diagnosis). Secondary outcome was the association with tau pathology (determined using neuropathology or positron emission tomography [PET]). ResultsMean age was 83.5 (SD, 8.5) years in cohort 1, 69.1 (SD, 10.3) years in cohort 2, and 35.8 (SD, 10.7) years in cohort 3; 38% were women in cohort 1, 51% in cohort 2, and 57% in cohort 3. In cohort 1, antemortem plasma P-tau217 differentiated neuropathologically defined AD from non-AD (area under the curve [AUC], 0.89 [95% CI, 0.81-0.97]) with significantly higher accuracy than plasma P-tau181 and neurofilament light chain (NfL) (AUC range, 0.50-0.72; P<.05). The discriminative accuracy of plasma P-tau217 in cohort 2 for clinical AD dementia vs other neurodegenerative diseases (AUC, 0.96 [95% CI, 0.93-0.98]) was significantly higher than plasma P-tau181, plasma NfL, and MRI measures (AUC range, 0.50-0.81; P<.001) but not significantly different compared with cerebrospinal fluid (CSF) P-tau217, CSF P-tau181, and tau-PET (AUC range, 0.90-0.99; P>.15). In cohort 3, plasma P-tau217 levels were significantly greater among PSEN1 mutation carriers, compared with noncarriers, from approximately 25 years and older, which is 20 years prior to estimated onset of MCI among mutation carriers. Plasma P-tau217 levels correlated with tau tangles in participants with (Spearman rho =0.64; P<.001), but not without (Spearman =0.15; P=.33), beta -amyloid plaques in cohort 1. In cohort 2, plasma P-tau217 discriminated abnormal vs normal tau-PET scans (AUC, 0.93 [95% CI, 0.91-0.96]) with significantly higher accuracy than plasma P-tau181, plasma NfL, CSF P-tau181, CSF A beta 42:A beta 40 ratio, and MRI measures (AUC range, 0.67-0.90; P<.05), but its performance was not significantly different compared with CSF P-tau217 (AUC, 0.96; P=.22). Conclusions and RelevanceAmong 1402 participants from 3 selected cohorts, plasma P-tau217 discriminated AD from other neurodegenerative diseases, with significantly higher accuracy than established plasma- and MRI-based biomarkers, and its performance was not significantly different from key CSF- or PET-based measures. Further research is needed to optimize the assay, validate the findings in unselected and diverse populations, and determine its potential role in clinical care. This cross-sectional study compares the accuracy of plasma tau phosphorylated at threonine 217 (P-tau217) levels vs other plasma-, MRI-, CSF-, and PET-based markers for distinguishing Alzheimer from other neurodegenerative diseases in 3 cohorts in Arizona, Sweden, and Columbia with or at risk for dementia.
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32. |
- Palmqvist, Sebastian, et al.
(författare)
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Performance of Fully Automated Plasma Assays as Screening Tests for Alzheimer Disease-Related beta-Amyloid Status
- 2019
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Ingår i: Jama Neurology. - : American Medical Association (AMA). - 2168-6149. ; 76:9, s. 1060-1069
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Tidskriftsartikel (refereegranskat)abstract
- Key PointsQuestionDo plasma levels of beta -amyloid 42, beta -amyloid 40, and tau detect cerebral beta -amyloid status when measured using fully automated immunoassays? FindingsIn 2 cross-sectional studies, plasma beta -amyloid 42 to beta -amyloid 40 ratio, measured using immunoassay, accurately predicted cerebral beta -amyloid status in all stages of Alzheimer disease in the BioFINDER cohort (n=842) and in an independent validation cohort (n=237). The diagnostic accuracy was further increased by analyzing APOE genotype. MeaningBlood-based beta -amyloid 42 and beta -amyloid 40 ratio together with APOE genotype may be used as prescreening tests in primary care and in clinical Alzheimer disease trials to lower the costs and number of positron emission tomography scans and lumbar punctures. This corss-sectional diagnostic study evaluates the accuracy of fully automated plasma assays in measuring plasma beta -amyloid and tau in patients with and without cognitive impairment in the Swedish BioFINDER study and an independent validation cohort. ImportanceAccurate blood-based biomarkers for Alzheimer disease (AD) might improve the diagnostic accuracy in primary care, referrals to memory clinics, and screenings for AD trials. ObjectiveTo examine the accuracy of plasma beta -amyloid (A beta) and tau measured using fully automated assays together with other blood-based biomarkers to detect cerebral A beta. Design, Setting, and ParticipantsTwo prospective, cross-sectional, multicenter studies. Study participants were consecutively enrolled between July 6, 2009, and February 11, 2015 (cohort 1), and between January 29, 2000, and October 11, 2006 (cohort 2). Data were analyzed in 2018. The first cohort comprised 842 participants (513 cognitively unimpaired [CU], 265 with mild cognitive impairment [MCI], and 64 with AD dementia) from the Swedish BioFINDER study. The validation cohort comprised 237 participants (34 CU, 109 MCI, and 94 AD dementia) from a German biomarker study. Main Outcome and MeasuresThe cerebrospinal fluid (CSF) A beta 42/A beta 40 ratio was used as the reference standard for brain A beta status. Plasma A beta 42, A beta 40 and tau were measured using Elecsys immunoassays (Roche Diagnostics) and examined as predictors of A beta status in logistic regression models in cohort 1 and replicated in cohort 2. Plasma neurofilament light chain (NFL) and heavy chain (NFH) and APOE genotype were also examined in cohort 1. ResultsThe mean (SD) age of the 842 participants in cohort 1 was 72 (5.6) years, with a range of 59 to 88 years, and 446 (52.5%) were female. For the 237 in cohort 2, mean (SD) age was 66 (10) years with a range of 23 to 85 years, and 120 (50.6%) were female. In cohort 1, plasma A beta 42 and A beta 40 predicted A beta status with an area under the receiver operating characteristic curve (AUC) of 0.80 (95% CI, 0.77-0.83). When adding APOE, the AUC increased significantly to 0.85 (95% CI, 0.82-0.88). Slight improvements were seen when adding plasma tau (AUC, 0.86; 95% CI, 0.83-0.88) or tau and NFL (AUC, 0.87; 95% CI, 0.84-0.89) to A beta 42, A beta 40 and APOE. The results were similar in CU and cognitively impaired participants, and in younger and older participants. Applying the plasma A beta 42 and A beta 40 model from cohort 1 in cohort 2 resulted in slightly higher AUC (0.86; 95% CI, 0.81-0.91), but plasma tau did not contribute. Using plasma A beta 42, A beta 40, and APOE in an AD trial screening scenario reduced positron emission tomography costs up to 30% to 50% depending on cutoff. Conclusions and RelevancePlasma A beta 42 and A beta 40 measured using Elecsys immunoassays predict A beta status in all stages of AD with similar accuracy in a validation cohort. Their accuracy can be further increased by analyzing APOE genotype. Potential future applications of these blood tests include prescreening of A beta positivity in clinical AD trials to lower the costs and number of positron emission tomography scans or lumbar punctures.
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33. |
- Palmqvist, Sebastian, et al.
(författare)
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Prediction of future Alzheimer's disease dementia using plasma phospho-tau combined with other accessible measures
- 2021
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 27, s. 1034-1042
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Tidskriftsartikel (refereegranskat)abstract
- Plasma P-tau, in combination with clinical measures, predicts future Alzheimer's disease dementia in two independent cohorts with high accuracy and is superior to the clinical diagnostic predictions of specialists. A combination of plasma phospho-tau (P-tau) and other accessible biomarkers might provide accurate prediction about the risk of developing Alzheimer's disease (AD) dementia. We examined this in participants with subjective cognitive decline and mild cognitive impairment from the BioFINDER (n = 340) and Alzheimer's Disease Neuroimaging Initiative (ADNI) (n = 543) studies. Plasma P-tau, plasma A beta 42/A beta 40, plasma neurofilament light, APOE genotype, brief cognitive tests and an AD-specific magnetic resonance imaging measure were examined using progression to AD as outcome. Within 4 years, plasma P-tau217 predicted AD accurately (area under the curve (AUC) = 0.83) in BioFINDER. Combining plasma P-tau217, memory, executive function and APOE produced higher accuracy (AUC = 0.91, P < 0.001). In ADNI, this model had similar AUC (0.90) using plasma P-tau181 instead of P-tau217. The model was implemented online for prediction of the individual probability of progressing to AD. Within 2 and 6 years, similar models had AUCs of 0.90-0.91 in both cohorts. Using cerebrospinal fluid P-tau, A beta 42/A beta 40 and neurofilament light instead of plasma biomarkers did not improve the accuracy significantly. The clinical predictions by memory clinic physicians had significantly lower accuracy (4-year AUC = 0.71). In summary, plasma P-tau, in combination with brief cognitive tests and APOE genotyping, might greatly improve the diagnostic prediction of AD and facilitate recruitment for AD trials.
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34. |
- Pereira, Joana B., et al.
(författare)
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Microglial activation protects against accumulation of tau aggregates in nondemented individuals with underlying Alzheimer’s disease pathology
- 2022
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Ingår i: Nature Aging. - : Springer Science and Business Media LLC. - 2662-8465. ; 2:12, s. 1138-1144
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Tidskriftsartikel (refereegranskat)abstract
- The role of microglia in tau accumulation is currently unclear but could provide an important insight into the mechanisms underlying Alzheimer’s disease (AD)1. Here, we measured the microglial marker soluble TREM2 and the disease-associated microglial activation stage 2 markers AXL, MERTK, GAS6, LPL, CST7, SPP1 and CSF1 in nondemented individuals from the Swedish BioFINDER-2 cohort who underwent longitudinal tau-positron emission tomography (PET), amyloid-PET and global cognitive assessment. To assess whether baseline microglial markers had an effect on AD-related changes, we studied three sub-groups of individuals: 121 with evidence of amyloid-PET pathology (A+), 64 with additional evidence of tau-PET pathology (A+T+) and 159 without amyloid- or tau-PET pathology (A−T−). Our results showed that increased levels of TREM2 were associated with slower amyloid accumulation in A+ individuals in addition to slower tau deposition and cognitive decline in A+T+ subjects. Similarly, higher levels of AXL, MERTK, GAS6, LPL, CST7 and CSF1 predicted slower tau accumulation and/or cognitive decline in the A+T+ group. These findings have important implications for future therapeutic strategies aiming to boost microglial protective functions in AD.
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35. |
- Pereira, Joana B., et al.
(författare)
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Untangling the association of amyloid-β and tau with synaptic and axonal loss in Alzheimer's disease.
- 2021
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Ingår i: Brain : a journal of neurology. - : Oxford University Press (OUP). - 1460-2156. ; 144:1, s. 310-324
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Tidskriftsartikel (refereegranskat)abstract
- It is currently unclear how amyloid-β and tau deposition are linked to changes in synaptic function and axonal structure over the course of Alzheimer's disease. Here, we assessed these relationships by measuring presynaptic (synaptosomal-associated protein 25, SNAP25; growth-associated protein 43, GAP43), postsynaptic (neurogranin, NRGN) and axonal (neurofilament light chain) markers in the CSF of individuals with varying levels of amyloid-β and tau pathology based on 18F-flutemetamol PET and 18F-flortaucipir PET. In addition, we explored the relationships between synaptic and axonal markers with cognition as well as functional and anatomical brain connectivity markers derived from resting-state functional MRI and diffusion tensor imaging. We found that the presynaptic and postsynaptic markers SNAP25, GAP43 and NRGN are elevated in early Alzheimer's disease i.e. in amyloid-β-positive individuals without evidence of tau pathology. These markers were associated with greater amyloid-β pathology, worse memory and functional changes in the default mode network. In contrast, neurofilament light chain was abnormal in later disease stages, i.e. in individuals with both amyloid-β and tau pathology, and correlated with more tau and worse global cognition. Altogether, these findings support the hypothesis that amyloid-β and tau might have differential downstream effects on synaptic and axonal function in a stage-dependent manner, with amyloid-related synaptic changes occurring first, followed by tau-related axonal degeneration.
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36. |
- Pichet Binette, Alexa, et al.
(författare)
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Combining plasma phospho-tau and accessible measures to evaluate progression to Alzheimer's dementia in mild cognitive impairment patients
- 2022
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Ingår i: Alzheimers Research & Therapy. - : Springer Science and Business Media LLC. - 1758-9193. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Up to now, there are no clinically available minimally invasive biomarkers to accurately identify mild cognitive impairment (MCI) patients who are at greater risk to progress to Alzheimer's disease (AD) dementia. The recent advent of blood-based markers opens the door for more accessible biomarkers. We aimed to identify which combinations of AD related plasma biomarkers and other easily accessible assessments best predict progression to AD dementia in patients with mild cognitive impairment (MCI). Methods: We included patients with amnestic MCI (n = 110) followed prospectively over 3 years to assess clinical status. Baseline plasma biomarkers (amyloid-beta 42/40, phosphorylated tau217 [p-tau217], neurofilament light and glial fibrillary acidic protein), hippocampal volume, APOE genotype, and cognitive tests were available. Logistic regressions with conversion to amyloid-positive AD dementia within 3 years as outcome was used to evaluate the performance of different biomarkers measured at baseline, used alone or in combination. The first analyses included only the plasma biomarkers to determine the ones most related to AD dementia conversion. Second, hippocampal volume, APOE genotype and a brief cognitive composite score (mPACC) were combined with the best plasma biomarker. Results: Of all plasma biomarker combinations, p-tau217 alone had the best performance for discriminating progression to AD dementia vs all other combinations (AUC 0.84, 95% CI 0.75-0.93). Next, combining p-tau217 with hippocampal volume, cognition, and APOE genotype provided the best discrimination between MCI progressors vs. non-progressors (AUC 0.89, 0.82-0.95). Across the few best models combining different markers, p-tau217 and cognition were consistently the main contributors. The most parsimonious model including p-tau217 and cognition had a similar model fit, but a slightly lower AUC (0.87, 0.79-0.95, p = 0 .07). Conclusion: We identified that combining plasma p-tau217 and a brief cognitive composite score was strongly related to greater risk of progression to AD dementia in MCI patients, suggesting that these measures could be key components of future prognostic algorithms for early AD.
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37. |
- Pichet Binette, Alexa, et al.
(författare)
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Confounding factors of Alzheimer's disease plasma biomarkers and their impact on clinical performance
- 2023
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Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 19:4, s. 1403-1414
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Plasma biomarkers will likely revolutionize the diagnostic work-up of Alzheimer's disease (AD) globally. Before widespread use, we need to determine if confounding factors affect the levels of these biomarkers, and their clinical utility. Methods Participants with plasma and CSF biomarkers, creatinine, body mass index (BMI), and medical history data were included (BioFINDER-1: n = 748, BioFINDER-2: n = 421). We measured beta-amyloid (A beta 42, A beta 40), phosphorylated tau (p-tau217, p-tau181), neurofilament light (NfL), and glial fibrillary acidic protein (GFAP). Results In both cohorts, creatinine and BMI were the main factors associated with NfL, GFAP, and to a lesser extent with p-tau. However, adjustment for BMI and creatinine had only minor effects in models predicting either the corresponding levels in CSF or subsequent development of dementia. Discussion Creatinine and BMI are related to certain plasma biomarkers levels, but they do not have clinically relevant confounding effects for the vast majority of individuals. Highlights Creatinine and body mass index (BMI) are related to certain plasma biomarker levels. Adjusting for creatinine and BMI has minor influence on plasma-cerebrospinal fluid (CSF) associations. Adjusting for creatinine and BMI has minor influence on prediction of dementia using plasma biomarkers.
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38. |
- Salvadó, Gemma, et al.
(författare)
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Optimal combinations of CSF biomarkers for predicting cognitive decline and clinical conversion in cognitively unimpaired participants and mild cognitive impairment patients: A multi-cohort study
- 2023
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Ingår i: Alzheimers & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 19:7, s. 2943-2955
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Our objective was determining the optimal combinations of cerebrospinal fluid (CSF) biomarkers for predicting disease progression in Alzheimer's disease (AD) and other neurodegenerative diseases.Methods: We included 1,983 participants from three different cohorts with longitudinal cognitive and clinical data, and baseline CSF levels of A beta 42, A beta 40, phosphorylated tau at threonine-181 (p-tau), neurofilament light (NfL), neurogranin, alpha-synuclein, soluble triggering receptor expressed on myeloid cells 2 (sTREM2), glial fibrillary acidic protein (GFAP), YKL-40, S100b, and interleukin 6 (IL-6) (Elecsys NeuroToolKit).Results: Change of modified Preclinical Alzheimer's Cognitive Composite (mPACC) in cognitively unimpaired (CU) was best predicted by p-tau/A beta 42 alone (R-2 >= 0.31) or together with NfL (R-2 = 0.25), while p-tau/A beta 42 (R-2 >= 0.19) was sufficient to accurately predict change of the Mini-Mental State Examination (MMSE) in mild cognitive impairment (MCI) patients. P-tau/A beta 42 (AUC >= 0.87) and p-tau/A beta 42 together with NfL (AUC >= 0.75) were the best predictors of conversion to AD and all-cause dementia, respectively.Discussion: P-tau/A beta 42 is sufficient for predicting progression in AD, with very high accuracy. Adding NfL improves the prediction of all-cause dementia conversion and cognitive decline.
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39. |
- Salvadó, Gemma, et al.
(författare)
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Specific associations between plasma biomarkers and postmortem amyloid plaque and tau tangle loads
- 2023
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Ingår i: Embo Molecular Medicine. - : EMBO. - 1757-4676 .- 1757-4684. ; 15:5
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Tidskriftsartikel (refereegranskat)abstract
- Several promising plasma biomarkers for Alzheimer's disease have been recently developed, but their neuropathological correlates have not yet been fully determined. To investigate and compare independent associations between multiple plasma biomarkers (p-tau181, p-tau217, p-tau231, A beta 42/40, GFAP, and NfL) and neuropathologic measures of amyloid and tau, we included 105 participants from the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND) with antemortem plasma samples and a postmortem neuropathological exam, 48 of whom had longitudinal p-tau217 and p-tau181. When simultaneously including plaque and tangle loads, the A beta 42/40 ratio and p-tau231 were only associated with plaques (rho(A beta 42/40)[95%CI] = -0.53[-0.65, -0.35], rho(p-tau231)[95%CI] = 0.28[0.10, 0.43]), GFAP was only associated with tangles (rho(GFAP)[95%CI] = 0.39[0.17, 0.57]), and p-tau217 and p-tau181 were associated with both plaques (rho(p-tau217)[95%CI] = 0.40[0.21, 0.56], rho(p-tau181)[95%CI] = 0.36[0.15, 0.50]) and tangles (rho(p-tau217)[95%CI] = 0.52[0.34, 0.66]; rho(p-tau181)[95%CI] = 0.36[0.17, 0.52]). A model combining p-tau217 and the A beta 42/40 ratio showed the highest accuracy for predicting the presence of Alzheimer's disease neuropathological change (ADNC, AUC[95%CI] = 0.89[0.82, 0.96]) and plaque load (R-2 = 0.55), while p-tau217 alone was optimal for predicting tangle load (R-2 = 0.45). Our results suggest that high-performing assays of plasma p-tau217 and A beta 42/40 might be an optimal combination to assess Alzheimer's-related pathology in vivo.
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40. |
- Scheeren Brum, Wagner, 1997, et al.
(författare)
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A blood-based biomarker workflow for optimal tau-PET referral in memory clinic settings.
- 2024
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Ingår i: Nature Communications. - 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Blood-based biomarkers for screening may guide tau positrion emissition tomography (PET) scan referrals to optimize prognostic evaluation in Alzheimer's disease. Plasma Aβ42/Aβ40, pTau181, pTau217, pTau231, NfL, and GFAP were measured along with tau-PET in memory clinic patients with subjective cognitive decline, mild cognitive impairment or dementia, in the Swedish BioFINDER-2 study (n=548) and in the TRIAD study (n=179). For each plasma biomarker, cutoffs were determined for 90%, 95%, or 97.5% sensitivity to detect tau-PET-positivity. We calculated the percentage of patients below the cutoffs (who would not undergo tau-PET; "saved scans") and the tau-PET-positivity rate among participants above the cutoffs (who would undergo tau-PET; "positive predictive value"). Generally, plasma pTau217 performed best. At the 95% sensitivity cutoff in both cohorts, pTau217 resulted in avoiding nearly half tau-PET scans, with a tau-PET-positivity rate among those who would be referred for a scan around 70%. And although tau-PET was strongly associated with subsequent cognitive decline, in BioFINDER-2 it predicted cognitive decline only among individuals above the referral cutoff on plasma pTau217, supporting that this workflow could reduce prognostically uninformative tau-PET scans. In conclusion, plasma pTau217 may guide selection of patients for tau-PET, when accurate prognostic information is of clinical value.
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41. |
- Therriault, Joseph, et al.
(författare)
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Comparison of immunoassay- with mass spectrometry-derived p-tau quantification for the detection of Alzheimer’s disease pathology
- 2024
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Ingår i: Molecular Neurodegeneration. - 1750-1326. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Antibody-based immunoassays have enabled quantification of very low concentrations of phosphorylated tau (p-tau) protein forms in cerebrospinal fluid (CSF), aiding in the diagnosis of AD. Mass spectrometry enables absolute quantification of multiple p-tau variants within a single run. The goal of this study was to compare the performance of mass spectrometry assessments of p-tau181, p-tau217 and p-tau231 with established immunoassay techniques. Methods: We measured p-tau181, p-tau217 and p-tau231 concentrations in CSF from 173 participants from the TRIAD cohort and 394 participants from the BioFINDER-2 cohort using both mass spectrometry and immunoassay methods. All subjects were clinically evaluated by dementia specialists and had amyloid-PET and tau-PET assessments. Bland–Altman analyses evaluated the agreement between immunoassay and mass spectrometry p-tau181, p-tau217 and p-tau231. P-tau associations with amyloid-PET and tau-PET uptake were also compared. Receiver Operating Characteristic (ROC) analyses compared the performance of mass spectrometry and immunoassays p-tau concentrations to identify amyloid-PET positivity. Results: Mass spectrometry and immunoassays of p-tau217 were highly comparable in terms of diagnostic performance, between-group effect sizes and associations with PET biomarkers. In contrast, p-tau181 and p-tau231 concentrations measured using antibody-free mass spectrometry had lower performance compared with immunoassays. Conclusions: Our results suggest that while similar overall, immunoassay-based p-tau biomarkers are slightly superior to antibody-free mass spectrometry-based p-tau biomarkers. Future work is needed to determine whether the potential to evaluate multiple biomarkers within a single run offsets the slightly lower performance of antibody-free mass spectrometry-based p-tau quantification.
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42. |
- Van Egroo, M., et al.
(författare)
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Ultra-high field imaging, plasma markers and autopsy data uncover a specific rostral locus coeruleus vulnerability to hyperphosphorylated tau
- 2023
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Ingår i: Molecular Psychiatry. - 1359-4184. ; 28:6, s. 2412-2422
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Tidskriftsartikel (refereegranskat)abstract
- Autopsy data indicate that the locus coeruleus (LC) is one of the first sites in the brain to accumulate hyperphosphorylated tau pathology, with the rostral part possibly being more vulnerable in the earlier stages of the disease. Taking advantage of recent developments in ultra-high field (7 T) imaging, we investigated whether imaging measures of the LC also reveal a specific anatomic correlation with tau using novel plasma biomarkers of different species of hyperphosphorylated tau, how early in adulthood these associations can be detected and if are associated with worse cognitive performance. To validate the anatomic correlations, we tested if a rostro-caudal gradient in tau pathology is also detected at autopsy in data from the Rush Memory and Aging Project (MAP). We found that higher plasma measures of phosphorylated tau, in particular ptau(231), correlated negatively with dorso-rostral LC integrity, whereas correlations for neurodegenerative plasma markers (neurofilament light, total tau) were scattered throughout the LC including middle to caudal sections. In contrast, the plasma A beta(42/40) ratio, associated with brain amyloidosis, did not correlate with LC integrity. These findings were specific to the rostral LC and not observed when using the entire LC or the hippocampus. Furthermore, in the MAP data, we observed higher rostral than caudal tangle density in the LC, independent of the disease stage. The in vivo LC-phosphorylated tau correlations became significant from midlife, with the earliest effect for ptau(231), starting at about age 55. Finally, interactions between lower rostral LC integrity and higher ptau(231) concentrations predicted lower cognitive performance. Together, these findings demonstrate a specific rostral vulnerability to early phosphorylated tau species that can be detected with dedicated magnetic resonance imaging measures, highlighting the promise of LC imaging as an early marker of AD-related processes.
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