| 1. |
- Palmqvist, Sebastian, et al.
(författare)
-
Detailed comparison of amyloid PET and CSF biomarkers for identifying early Alzheimer disease
- 2015
-
Ingår i: Neurology. - : Lippincott Williams & Wilkins. - 1526-632X .- 0028-3878. ; 85:14, s. 1240-1249
-
Tidskriftsartikel (refereegranskat)abstract
- Objective:To compare the diagnostic accuracy of CSF biomarkers and amyloid PET for diagnosing early-stage Alzheimer disease (AD).Methods:From the prospective, longitudinal BioFINDER study, we included 122 healthy elderly and 34 patients with mild cognitive impairment who developed AD dementia within 3 years (MCI-AD). -Amyloid (A) deposition in 9 brain regions was examined with [F-18]-flutemetamol PET. CSF was analyzed with INNOTEST and EUROIMMUN ELISAs. The results were replicated in 146 controls and 64 patients with MCI-AD from the Alzheimer's Disease Neuroimaging Initiative study.Results:The best CSF measures for identifying MCI-AD were A42/total tau (t-tau) and A42/hyperphosphorylated tau (p-tau) (area under the curve [AUC] 0.93-0.94). The best PET measures performed similarly (AUC 0.92-0.93; anterior cingulate, posterior cingulate/precuneus, and global neocortical uptake). CSF A42/t-tau and A42/p-tau performed better than CSF A42 and A42/40 (AUC difference 0.03-0.12, p < 0.05). Using nonoptimized cutoffs, CSF A42/t-tau had the highest accuracy of all CSF/PET biomarkers (sensitivity 97%, specificity 83%). The combination of CSF and PET was not better than using either biomarker separately.Conclusions:Amyloid PET and CSF biomarkers can identify early AD with high accuracy. There were no differences between the best CSF and PET measures and no improvement when combining them. Regional PET measures were not better than assessing the global A deposition. The results were replicated in an independent cohort using another CSF assay and PET tracer. The choice between CSF and amyloid PET biomarkers for identifying early AD can be based on availability, costs, and doctor/patient preferences since both have equally high diagnostic accuracy.Classification of evidence:This study provides Class III evidence that amyloid PET and CSF biomarkers identify early-stage AD equally accurately.
|
|
| 2. |
- Schöll, Michael, 1980, et al.
(författare)
-
Biomarkers for tau pathology.
- 2019
-
Ingår i: Molecular and cellular neurosciences. - : Elsevier BV. - 1095-9327 .- 1044-7431. ; 97, s. 18-33
-
Forskningsöversikt (refereegranskat)abstract
- The aggregation of fibrils of hyperphosphorylated and C-terminally truncated microtubule-associated tau protein characterizes 80% of all dementia disorders, the most common neurodegenerative disorders. These so-called tauopathies are hitherto not curable and their diagnosis, especially at early disease stages, has traditionally proven difficult. A keystone in the diagnosis of tauopathies was the development of methods to assess levels of tau protein in vivo in cerebrospinal fluid, which has significantly improved our knowledge about these conditions. Tau proteins have also been measured in blood, but the importance of tau-related changes in blood is still unclear. The recent addition of positron emission tomography ligands to visualize, map and quantify tau pathology has further contributed with information about the temporal and spatial characteristics of tau accumulation in the living brain. Together, the measurement of tau with fluid biomarkers and positron emission tomography constitutes the basis for a highly active field of research. This review describes the current state of biomarkers for tau biomarkers derived from neuroimaging and from the analysis of bodily fluids and their roles in the detection, diagnosis and prognosis of tau-associated neurodegenerative disorders, as well as their associations with neuropathological findings, and aims to provide a perspective on how these biomarkers might be employed prospectively in research and clinical settings.
|
|
| 3. |
- Johansson, Per, 1966, et al.
(författare)
-
Reduced cerebrospinal fluid concentration of interleukin-12/23 subunit p40 in patients with cognitive impairment.
- 2017
-
Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 12:5
-
Tidskriftsartikel (refereegranskat)abstract
- The role of inflammation in Alzheimer's disease (AD) and other cognitive disorders is unclear. In a well-defined mono-center population, we measured cytokines and chemokines in paired serum and cerebrospinal fluid (CSF) samples.Consecutive patients with AD (n = 30), stable mild cognitive impairment (SMCI, n = 11), other dementias (n = 11), and healthy controls (n = 18) were included. None of the subjects was treated with glucocorticoids, cholinesterase inhibitors, or non-steroidal anti-inflammatory drugs. Serum and CSF concentrations of interleukin-6 (IL-6), IL-8, IL-12/23 p40, IL-15, IL-16, vascular endothelial growth factor-A (VEGF-A), and three chemokines were measured using a multiplex panel.After correction for multiple comparisons, only CSF IL-12/23 p40 concentration differed significantly between the total patient group (n = 52) and controls (n = 18; p = 0.002). Further analyses showed that CSF IL-12/23 p40 concentration was decreased in all patient subgroups (AD, other dementias, and SMCI) compared to healthy controls (p < 0.01, p < 0.05, and p < 0.05, respectively). In the total study population (n = 70), CSF IL-12/23 p40 concentrations correlated positively with CSF concentrations of β-amyloid1-42 (Aβ1-42) and phosphorylated tau protein (P-tau) whereas in AD patients (n = 30), CSF IL-12/23 p40 only correlated positively with CSF P-Tau (r = 0.46, p = 0.01).Most cytokines and chemokines were similar in patients and controls, but CSF IL-12/23 subunit p40 concentration was decreased in patients with cognitive impairment, and correlated with markers of AD disease status. Further studies are needed to evaluate the role of CSF IL-12/23 p40 in other dementias and SMCI.
|
|
| 4. |
- Frisoni, G. B., et al.
(författare)
-
Strategic roadmap for an early diagnosis of Alzheimer's disease based on biomarkers
- 2017
-
Ingår i: Lancet Neurology. - 1474-4422 .- 1474-4465. ; 16:8, s. 661-676
-
Tidskriftsartikel (refereegranskat)abstract
- The diagnosis of Alzheimer's disease can be improved by the use of biological measures. Biomarkers of functional impairment, neuronal loss, and protein deposition that can be assessed by neuroimaging (ie, MRI and PET) or CSF analysis are increasingly being used to diagnose Alzheimer's disease in research studies and specialist clinical settings. However, the validation of the clinical usefulness of these biomarkers is incomplete, and that is hampering reimbursement for these tests by health insurance providers, their widespread clinical implementation, and improvements in quality of health care. We have developed a strategic five-phase roadmap to foster the clinical validation of biomarkers in Alzheimer's disease, adapted from the approach for cancer biomarkers. Sufficient evidence of analytical validity (phase 1 of a structured framework adapted from oncology) is available for all biomarkers, but their clinical validity (phases 2 and 3) and clinical utility (phases 4 and 5) are incomplete. To complete these phases, research priorities include the standardisation of the readout of these assays and thresholds for normality, the evaluation of their performance in detecting early disease, the development of diagnostic algorithms comprising combinations of biomarkers, and the development of clinical guidelines for the use of biomarkers in qualified memory clinics.
|
|
| 5. |
- Janelidze, Shorena, et al.
(författare)
-
Increased blood-brain barrier permeability is associated with dementia and diabetes but not amyloid pathology or APOE genotype
- 2017
-
Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 51, s. 104-112
-
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.
|
|
| 6. |
- Engström, Åsa, et al.
(författare)
-
Losing the identity of a hockey player : the long-term effects of concussions
- 2020
-
Ingår i: Concussion. - : Future Medicine. - 2056-3299. ; 5:2
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: To describe what suffering multiple concussions meant for former semi-professional or professional hockey players who were forced to end their career. Results: Nine former Swedish hockey players, who once played on national or professional teams were interviewed. The interviews were analyzed with reference to hermeneutic phenomenology to interpret and explain their experiences. The theme of losing one’s identity as a hockey player was constructed from five subthemes: being limited in everyday life, returning to the hockey stadium as soon as possible, forming a post career identity, lacking understanding and support, and preventing injuries by respecting other players. Conclusion: The former hockey players struggled with developing their off-the-ice identities and with finding other sources of meaning for their lives.Lay abstractDespite considerable attention to improving the initial management of concussions suffered by hockey players, few studies have examined their long-term effects. In response, the study reported here aimed to describe what suffering multiple concussions meant for former semi-professional or professional hockey players who were forced to end their career. Nine former Swedish hockey players, who once played on national or professional teams were interviewed and the interviews were analyzed in order to interpret and explain their experiences. The overall theme was formulated as losing one’s identity as a hockey player. In conclusion, the former hockey players seem to struggle with developing their off-the-ice identities and with finding other sources of meaning for their lives.
|
|
| 7. |
- van Westen, Danielle, et al.
(författare)
-
Cerebral white matter lesions - associations with A beta isoforms and amyloid PET
- 2016
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6:20709
-
Tidskriftsartikel (refereegranskat)abstract
- Small vessel disease (SVD) and amyloid deposition may promote each other, with a potential association between SVD and altered production or clearance of beta-amyloid (A beta) affecting its cleavage products. We investigated the relationship between SVD, multiple isoforms of A beta in cerebrospinal fluid (CSF) and cortical A beta in 831 subjects with cognitive performance ranging from normal to Alzheimer's disease (AD) (the Swedish BioFINDER study). SVD was estimated as white matter lesions (WML) and lacunes. 18F-flutemetamol PET was performed in 321 subjects. Lower CSF levels of A beta 38 and A beta 40 were consistently associated with increased WML in all subgroups, while lower levels of CSF A beta 42 were associated with WML mainly in AD. CSF A beta 38 and A beta 40 were associated with regional WML in all regions, while CSF A beta 42 was associated with temporal WML only. A composite measure of 18F-flutemetamol uptake was not associated with WML, and regional 18F-flutemetamol uptake only with temporal WML. Lacunes were not associated with A beta isoforms nor 18F-flutemetamol uptake. Our results suggest that WML may be associated with alterations in the production or clearance of A beta species, particularly of A beta 38 and A beta 40. However, in AD cases, A beta 42 pathology might be associated with WML, especially in the temporal lobe.
|
|
| 8. |
- Huebschmann, Nathan A, et al.
(författare)
-
Comparing Glial Fibrillary Acidic Protein (GFAP) in Serum and Plasma Following Mild Traumatic Brain Injury in Older Adults.
- 2020
-
Ingår i: Frontiers in neurology. - : Frontiers Media SA. - 1664-2295. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Identification and validation of blood-based biomarkers for the diagnosis and prognosis of mild traumatic brain injury (mTBI) is of critical importance. There have been calls for more research on mTBI in older adults. We compared blood-based protein marker glial fibrillary acidic protein (GFAP) concentrations in serum and in plasma within the same cohort of older adults and assessed their ability to discriminate between individuals based on intracranial abnormalities and functional outcome following mTBI. Methods: A sample of 121 older adults [≥50 years old with head computed tomography (CT), n = 92] seeking medical care for a head injury [Glasgow Coma Scale scores of 14 (n = 6; 5.0%) or 15 (n = 115; 95.0%)] were enrolled from the emergency department (ED). The mean time between injury and blood sampling was 3.4 h (SD = 2.1; range = 0.5-11.7). Serum GFAP concentration was measured first using the Human Neurology 4-Plex Assay, while plasma GFAP concentration was later measured using the GFAP Discovery Kit, both on an HD-1 Single molecule array (Simoa) instrument. Glasgow Outcome Scale-Extended was assessed 1 week after injury. Results: Both serum and plasma GFAP levels were significantly higher in those with abnormal CT scans compared to those with normal head CT scans (plasma: U = 1,198, p < 0.001; serum: U = 1,253, p < 0.001). The ability to discriminate those with and without intracranial abnormalities was comparable between serum (AUC = 0.814) and plasma (AUC = 0.778). In the total sample, GFAP concentrations were considerably higher in plasma than in serum (Wilcoxon signed-rank test z = 0.42, p < 0.001, r = 0.42). Serum and plasma GFAP levels were highly correlated in the total sample and within all subgroups (Spearman's rho range: 0.826-0.907). Both serum and plasma GFAP levels were significantly higher in those with poor compared to good functional outcome (serum: U = 1,625, p = 0.002; plasma: U = 1,539, p = 0.013). Neither plasma (AUC = 0.653) nor serum (AUC = 0.690) GFAP were adequate predictors of functional outcome 1 week after injury. Conclusions: Despite differences in concentration, serum and plasma GFAP levels were highly correlated and had similar discriminability between those with and without intracranial abnormalities on head CT following an mTBI. Neither serum nor plasma GFAP had adequate discriminability to identify patients who would have poor functional outcome.
|
|
| 9. |
- Kanberg, Nelly, et al.
(författare)
-
Neurochemical evidence of astrocytic and neuronal injury commonly found in COVID-19.
- 2020
-
Ingår i: Neurology. - 1526-632X .- 0028-3878. ; 95:12, s. e1754-e1759
-
Tidskriftsartikel (refereegranskat)abstract
- To test the hypothesis that coronavirus disease 2019 (COVID-19) has an impact on the CNS by measuring plasma biomarkers of CNS injury.We recruited 47 patients with mild (n = 20), moderate (n = 9), or severe (n = 18) COVID-19 and measured 2 plasma biomarkers of CNS injury by single molecule array, neurofilament light chain protein (NfL; a marker of intra-axonal neuronal injury) and glial fibrillary acidic protein (GFAp; a marker of astrocytic activation/injury), in samples collected at presentation and again in a subset after a mean of 11.4 days. Cross-sectional results were compared with results from 33 age-matched controls derived from an independent cohort.The patients with severe COVID-19 had higher plasma concentrations of GFAp (p = 0.001) and NfL (p < 0.001) than controls, while GFAp was also increased in patients with moderate disease (p = 0.03). In patients with severe disease, an early peak in plasma GFAp decreased on follow-up (p < 0.01), while NfL showed a sustained increase from first to last follow-up (p < 0.01), perhaps reflecting a sequence of early astrocytic response and more delayed axonal injury.We show neurochemical evidence of neuronal injury and glial activation in patients with moderate and severe COVID-19. Further studies are needed to clarify the frequency and nature of COVID-19-related CNS damage and its relation to both clinically defined CNS events such as hypoxic and ischemic events and mechanisms more closely linked to systemic severe acute respiratory syndrome coronavirus 2 infection and consequent immune activation, as well as to evaluate the clinical utility of monitoring plasma NfL and GFAp in the management of this group of patients.
|
|
| 10. |
- Pikwer, Andreas, et al.
(författare)
-
Effects of surgery and propofol-remifentanil total intravenous anesthesia on cerebrospinal fluid biomarkers of inflammation, Alzheimer's disease, and neuronal injury in humans: a cohort study
- 2017
-
Ingår i: Journal of Neuroinflammation. - : Springer Science and Business Media LLC. - 1742-2094. ; 14
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Surgery and anesthesia have been linked to postoperative cognitive disturbance and increased risk of Alzheimer's disease. It is not clear by which mechanisms this increased risk for cognitive disease is mediated. Further, amyloid beta production has been suggested to depend on the sleep-wake cycle and neuronal activity. The aim of the present study was to examine if cerebrospinal fluid (CSF) concentrations of a number of biomarkers for Alzheimer's disease-related processes, including amyloid beta, neuronal injury, and inflammation, changed over time during intravenous anesthesia in surgical patients. Methods: We included patients scheduled for hysterectomy via laparotomy during general anesthesia with intravenous propofol and remifentanil. CSF samples were obtained before, during, and after surgery (5 h after induction) and tested for 27 biomarkers. Changes over time were tested with linear mixed effects models. Results: A total of 22 patients, all females, were included. The mean age was 50 years (+/- 9 SD). The mean duration of the anesthesia was 145 min (+/- 40 SD). Interleukin (IL)-6, IL-8, monocyte chemoattractant protein 1, and vascular endothelial growth factor A increased over time. IL-15 and IL-7 decreased slightly over time. Macrophage inflammatory protein 1 beta and placental growth factor also changed significantly. There were no significant effects on amyloid beta (A beta) or tau biomarkers. Conclusions: Surgery and general anesthesia with intravenous propofol and remifentanil induce, during and in the short term after the procedure, a neuroinflammatory response which is dominated by monocyte attractants, without biomarker signs of the effects on Alzheimer's disease pathology or neuronal injury.
|
|
