| 1. |
- Bridel, Claire, et al.
(author)
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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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In: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149 .- 2168-6157. ; 76:9, s. 1035-1048
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Research review (peer-reviewed)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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| 2. |
- Moseby-Knappe, Marion, et al.
(author)
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Serum Neurofilament Light Chain for Prognosis of Outcome after Cardiac Arrest
- 2019
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In: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149 .- 2168-6157. ; 76:1, s. 64-64
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Journal article (peer-reviewed)abstract
- Importance: Prognostication of neurologic outcome after cardiac arrest is an important but challenging aspect of patient therapy management in critical care units. Objective: To determine whether serum neurofilament light chain (NFL) levels can be used for prognostication of neurologic outcome after cardiac arrest. Design, Setting and Participants: Prospective clinical biobank study of data from the randomized Target Temperature Management After Cardiac Arrest trial, an international, multicenter study with 29 participating sites. Patients were included between November 11, 2010, and January 10, 2013. Serum NFL levels were analyzed between August 1 and August 23, 2017, after trial completion. A total of 782 unconscious patients with out-of-hospital cardiac arrest of presumed cardiac origin were eligible. Exposures: Serum NFL concentrations analyzed at 24, 48, and 72 hours after cardiac arrest with an ultrasensitive immunoassay. Main Outcomes and Measures: Poor neurologic outcome at 6-month follow-up, defined according to the Cerebral Performance Category Scale as cerebral performance category 3 (severe cerebral disability), 4 (coma), or 5 (brain death). Results: Of 782 eligible patients, 65 patients (8.3%) were excluded because of issues with aliquoting, missing sampling, missing outcome, or transport problems of samples. Of the 717 patients included (91.7%), 580 were men (80.9%) and median (interquartile range [IQR]) age was 65 (56-73) years. A total of 360 patients (50.2%) had poor neurologic outcome at 6 months. Median (IQR) serum NFL level was significantly increased in the patients with poor outcome vs good outcome at 24 hours (1426 [299-3577] vs 37 [20-70] pg/mL), 48 hours (3240 [623-8271] vs 46 [26-101] pg/mL), and 72 hours (3344 [845-7838] vs 54 [30-122] pg/mL) (P <.001 at all time points), with high overall performance (area under the curve, 0.94-0.95) and high sensitivities at high specificities (eg, 69% sensitivity with 98% specificity at 24 hours). Serum NFL levels had significantly greater performance than the other biochemical serum markers (ie, tau, neuron-specific enolase, and S100). At comparable specificities, serum NFL levels had greater sensitivity for poor outcome compared with routine electroencephalogram, somatosensory-evoked potentials, head computed tomography, and both pupillary and corneal reflexes (ranging from 29.2% to 49.0% greater for serum NFL level). Conclusions and Relevance: Findings from this study suggest that the serum NFL level is a highly predictive marker of long-term poor neurologic outcome at 24 hours after cardiac arrest and may be a useful complement to currently available neurologic prognostication methods.
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| 3. |
- Mattsson, Niklas, et al.
(author)
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Association Between Longitudinal Plasma Neurofilament Light and Neurodegeneration in Patients With Alzheimer Disease
- 2019
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In: Jama Neurology. - : American Medical Association (AMA). - 2168-6149. ; 76:7, s. 791-799
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Journal article (peer-reviewed)abstract
- IMPORTANCE Plasma neurofilament light (NfL) has been suggested as a noninvasive biomarker to monitor neurodegeneration in Alzheimer disease (AD), but studies are lacking. OBJECTIVE To examine whether longitudinal plasma NfL levels are associated with other hallmarks of AD. DESIGN, SETTING, AND PARTICIPANTS This North American cohort study used data from 1583 individuals in the multicenter Alzheimer's Disease Neuroimaging Initiative study from September 7, 2005, through June 16, 2016. Patients were eligible for inclusion if they had NfL measurements. Annual plasma NfL samples were collected for up to 11 years and were analyzed in 2018. EXPOSURES Clinical diagnosis, A beta and tau cerebrospinal fluid (CSF) biomarkers, imaging measures (magnetic resonance imaging and fluorodeoxyglucose-positron emission tomography), and tests on cognitive scores. MAIN OUTCOMES AND MEASURES The primary outcome was the association between baseline exposures (diagnosis, CSF biomarkers, imaging measures, and cognition) and longitudinal plasma NfL levels, analyzed by an ultrasensitive assay. The secondary outcomes were the associations between a multimodal classification scheme with A beta, tau, and neurodegeneration (ie, the ATN system) and plasma NfL levels and between longitudinal changes in plasma NfL levels and changes in the other measures. RESULTS Of the included 1583 participants, 716 (45.2%) were women, and the mean (SD) age was 72.9 (7.1) years; 401 had no cognitive impairment, 855 had mild cognitive impairment, and 327 had AD dementia. The NfL level was increased at baseline in patients with mild cognitive impairment and AD dementia (mean levels: cognitive unimpairment, 32.1 ng/L; mild cognitive impairment, 37.9 ng/L; and AD dementia, 45.9 ng/L; P<.001) and increased in all diagnostic groups, with the greatest increase in patients with AD dementia. A longitudinal increase in NfL level correlated with baseline CSF biomarkers (low A beta 42 [P=.001], high total tau [P=.02], and high phosphorylated tau levels [P=.02]), magnetic resonance imaging measures (small hippocampal volumes [P<.001], thin regional cortices [P=.009], and large ventricular volumes [P=.002]), low fluorodeoxyglucose-positron emission tomography uptake (P=.01), and poor cognitive performance (P<.001) for a global cognitive score. With use of the ATN system, increased baseline NfL levels were seen in A-T+N+ (P<.001), A+T-N+ (P<.001), and A+T+N+ (P<.001), and increased rates of NfL levels were seen in A-T+N- (P=.009), A-T+N+ (P=.02), A+T-N+ (P=.04), and A+T+N+ (P=.002). Faster increase in NfL levels correlated with faster increase in CSF biomarkers of neuronal injury, faster rates of atrophy and hypometabolism, and faster worsening in global cognition (all P<.05 in patients with mild cognitive impairment; associations differed slightly in cognitively unimpaired controls and patients with AD dementia). CONCLUSIONS AND RELEVANCE The findings suggest that plasma NfL can be used as a noninvasive biomarker associated with neurodegeneration in patients with AD and may be useful to monitor effects in trials of disease-modifying drugs.
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| 4. |
- Mattsson, Niklas, et al.
(author)
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Staging β -Amyloid Pathology with Amyloid Positron Emission Tomography
- 2019
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In: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149. ; 76:11, s. 1319-1329
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Journal article (peer-reviewed)abstract
- Importance: Different brain regions appear to be involved during β-amyloid (Aβ) accumulation in Alzheimer disease (AD), but a longitudinally valid system to track Aβ stages in vivo using positron emission tomography (PET) is lacking. Objective: To construct a longitudinally valid in vivo staging system for AD using amyloid PET. Design, Setting, and Participants: Longitudinal multicenter cohort study using data accessed on August 20, 2018, from the Alzheimer's Disease Neuroimaging Initiative database of scans performed from June 9, 2010, to July 12, 2018, from 741 persons: 304 without cognitive impairment, 384 with mild cognitive impairment, and 53 with AD dementia. Cerebrospinal fluid (CSF) Aβ42 and fluorine 18-labeled florbetapir (18F-florbetapir) data were used to determine early, intermediate, and late regions of Aβ accumulation. β-Amyloid stages ranging from 0 to 3 were constructed using these composites. Each subsequent stage required involvement of more advanced regions. Patients were followed up at 2, 4, and 6 years. Replication and validation were conducted using an independent cohort (Swedish BioFINDER) and gene expression information from the Allen Human Brain Atlas database. Analyses were conducted August 21, 2018, to May 24, 2019. Main Outcomes and Measures: The main outcome was change in stage. Stages were compared for diagnosis, CSF biomarkers of tau, and longitudinal atrophy, cognitive measures, and regional gene expression. Transitions between stages were tested using longitudinal 18F-florbetapir data. Results: Among 641 participants with CSF Aβ42 data and at least two 18F-florbetapir scans, 335 (52.3%) were male. The early region of Aβ accumulation included the precuneus, posterior cingulate, isthmus cingulate, insula, and medial and lateral orbitofrontal cortices. The late region included the lingual, pericalcarine, paracentral, precentral, and postcentral cortices. The intermediate region included remaining brain regions with increased accumulation rates. In 2072 PET scans from 741 participants, 2039 (98.4%) were unambiguously staged. At baseline, participants with stage 0 (n = 402) had a 14.7% (95% CI, 11.2%-18.1%) probability of progression to a higher stage; stage 1 (n = 21), 71.4% (95% CI, 50.0%-90.9%); and stage 2 (n = 79), 53.1% (95% CI, 42.2%-64.0%). Seven of the 741 participants (0.9%) reverted to a lower stage. Higher stages were associated with lower CSF Aβ42 concentrations (from stage 1 at baseline), greater CSF P-tau (from stage 1) and CSF T-tau (from stage 2), and accelerated cognitive decline (from stage 2) and atrophy (from stage 3), even when adjusting for clinical diagnosis. Key findings were replicated in the BioFINDER cohort (N = 474). The regions of different stages differed by gene expression profiles when using the transcriptome from the Allen Human Brain Atlas, especially involving genes associated with voltage-gated ion channel activity especially involving genes associated with voltage-gated ion channel activity, but also blood circulation, axon guidance, and lipid transportation. Conclusions and Relevance: Results of this study suggest that this robust staging system of Aβ accumulation may be useful for monitoring patients throughout the course of AD. Progression through stages may depend on underlying selective vulnerability in different brain regions.
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| 5. |
- Palmqvist, Sebastian, et al.
(author)
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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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In: Jama Neurology. - : American Medical Association (AMA). - 2168-6149. ; 76:9, s. 1060-1069
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Journal article (peer-reviewed)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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