| 1. |
- Edsbagge, Mikael, et al.
(författare)
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Alzheimer's Disease-Associated Cerebrospinal Fluid (CSF) Biomarkers do not Correlate with CSF Volumes or CSF Production Rate.
- 2017
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Ingår i: Journal of Alzheimer's disease : JAD. - : IOS Press. - 1875-8908 .- 1387-2877. ; 58:3, s. 821-828
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Tidskriftsartikel (refereegranskat)abstract
- Neuropathologically, Alzheimer's disease (AD) is characterized by accumulation of a 42 amino acid peptide called amyloid-β (Aβ42) in extracellular senile plaques together with intraneuronal inclusions of hyperphosphorylated tau protein in neurofibrillary tangles and neuronal degeneration. These changes are reflected in the cerebrospinal fluid (CSF), the volumes and production rates of which vary considerably between individuals, by reduced concentration of Aβ42, increased concentration of phosphorylated tau (P-tau) protein, and increased concentration of total tau (T-tau) protein, respectively.To examine the outstanding question if CSF concentrations of AD associated biomarkers are influenced by variations in CSF volumes, CSF production rate, and intracranial pressure in healthy individuals.CSF concentrations of Aβ42, P-tau, and T-tau, as well as a number of other AD-related CSF biomarkers were analyzed together with intracranial subarachnoid, ventricular, and spinal CSF volumes, as assessed by magnetic resonance imaging volumetric measurements, and CSF production rate in 19 cognitively normal healthy subjects (mean age 70.6, SD 3.6 years).Negative correlations were seen between the concentrations of three CSF biomarkers (albumin ratio, Aβ38, and Aβ40), and ventricular CSF volume, but apart from this finding, no significant correlations were observed.These results speak against inter-individual variations in CSF volume and production rate as important confounds in the AD biomarker research field.
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| 2. |
- Johansson, Per, et al.
(författare)
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Cerebrospinal Fluid Biomarkers for Alzheimer's Disease: Diagnostic Performance in a Homogeneous Mono-Center Population
- 2011
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 24:3, s. 537-546
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Tidskriftsartikel (refereegranskat)abstract
- The cerebrospinal fluid (CSF) biomarkers amyloid-beta (A beta)(1-42), T-tau, and P-tau have good diagnostic accuracy for clinically diagnosed Alzheimer's disease (AD). However, in multi-center studies, the predictive values of the CSF biomarkers have been lower, possibly due to differences in procedures for lumbar puncture and CSF handling and storage, and to differences in patient populations, clinical evaluations, and diagnostic procedures. Here we investigate the diagnostic accuracy of CSF biomarkers in a well defined homogeneous mono-center population. We also evaluate an extended panel of amyloid related biomarkers. Sixty consecutive patients admitted for cognitive impairment to a memory clinic were recruited. The participants included patients with AD or mild cognitive impairment (MCI) diagnosed with AD upon follow-up (n = 32), patients with stable MCI (n = 13), patients with other dementias diagnosed at primary evaluation or upon follow-up (n = 15), and healthy controls (n = 20). CSF was analyzed for A beta(1-42), T-tau, P-tau, A beta(X-38), A beta(X-40), A beta(X-42), sA beta PP alpha, and sA beta PP beta. In multivariate analysis, the core biomarkers A beta(1-42), T-tau, and P-tau demonstrated a high ability to diagnose AD versus the combined groups of controls and stable MCI, with an area under the receiver operating characteristic curve (AUROC) of 0.97 (95% CI 0.93-1.00, p < 0.0001). The additional biomarkers only marginally increased AUROC to 0.98 (95% CI 0.95-1.00, p < 0.0001), this increase mainly mediated by A beta(X-42). In conclusion, CSF biomarkers A beta(1-42), T-tau, and P-tau have very high diagnostic accuracy in a well defined cohort of untreated patients, demonstrating the excellent potency of CSF biomarkers to identify pathological processes in AD when a stringent analytical protocol is used.
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| 3. |
- Johansson, Per, 1966, et al.
(författare)
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Reduced Cerebrospinal Fluid Concentration of Apolipoprotein A-I in Patients with Alzheimer's Disease.
- 2017
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Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908 .- 1387-2877. ; 59:3, s. 1017-1026
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Tidskriftsartikel (refereegranskat)abstract
- Apolipoprotein E (ApoE) has been extensively studied in Alzheimer's disease (AD), but little is known of apolipoprotein A-I (ApoA-I) in cerebrospinal fluid (CSF).Plasma lipids as well as ApoA-I and ApoE in plasma and CSF were determined and related to Mini-Mental State Examination (MMSE) score, APOE genotype, and CSF AD biomarkers.Consecutive patients with AD (n=29), stable mild cognitive impairment (n=13), other dementias (n=14), and healthy controls (n=18) were included at a single center.AD patients had higher plasma triglycerides and lower CSF ApoA-I concentration than controls (both p<0.05). CSF ApoE concentration was reduced in other dementias (p<0.01). In AD as well as other dementias, the ratios between CSF and plasma concentrations of both ApoA-I and ApoE were lower than those in the controls. ApoA-I and ApoE in plasma and CSF were not influenced by APOEɛ4 allele distribution. In the total study population (n=74), CSF ApoA-I correlated positively with MMSE score (r=0.26, p<0.05) and negatively with CSF P-tau (r=-0.25, p<0.05). CSF ApoE correlated positively with CSF concentrations of T-tau and P-tau in the total study population and in AD patients.CSF ApoA-I was reduced in AD patients and associated with measures of cognitive function and AD disease status. The mechanisms underlying the decreased CSF:plasma ratios of ApoA-I and ApoE in AD and other dementias need to be explored in further studies.
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| 4. |
- Manniche, C., et al.
(författare)
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Cerebrospinal Fluid Biomarkers to Differentiate Idiopathic Normal Pressure Hydrocephalus from Subcortical Ischemic Vascular Disease
- 2020
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Ingår i: Journal of Alzheimers Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 75:3, s. 937-947
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Tidskriftsartikel (refereegranskat)abstract
- Background: Idiopathic normal pressure hydrocephalus (iNPH) remains a challenge to differentiate from subcortical ischemic vascular disease (SIVD). Despite major research efforts, the cerebrospinal fluid (CSF) biomarker profiles of the two diseases are still not known in detail. Objective: To determine if novel CSF biomarkers, neurofilament light (NFL) reflecting axonal damage, the synaptic protein neurogranin (NG), and the astroglial marker chitinase-3-like protein 1 (YKL-40), and the core Alzheimer's disease (AD) biomarkers, amyloid-beta 42 (A beta(42)), total tau (t-tau), phosphorylated tau (p-tau), can differentiate iNPH from SIVD. Patients with AD and healthy controls (HC) were included for comparison purposes. Methods: Patients with iNPH (n = 28), SIVD (n = 30), AD (n = 57), and HC (n = 33) were retrospectively included from the Danish Dementia Biobank. All patients with iNPH had effect of shunt surgery with a follow-up period of 4 to 69 months. CSF biomarkers were measured using immunoassays. Results: Lower levels of NFL, NG, A beta(42), and t-tau were found in patients with iNPH versus SIVD, while YKL-40 and p-tau were similar in the two diseases. NFL and A beta(42) were the most reliable biomarkers to differentiate iNPH from SIVD with an area under the curve (AUC) on 0.82 and 0.80, respectively. Combining NFL with A beta(42), t-tau, and p-tau resulted in an AUC of 0.90, which was equivalent to the diagnostic accuracy of all six biomarkers combined. Conclusion: An addition of NFL to the CSF panel of A beta(42), t-tau, and p-tau may improve the differentiation of iNPH from SIVD.
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| 5. |
- Mattsson, Niklas, 1979, et al.
(författare)
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Converging Pathways of Chromogranin and Amyloid Metabolism in the Brain
- 2010
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 20:4, s. 1039-1048
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Tidskriftsartikel (refereegranskat)abstract
- Much is unknown regarding the regulation of Alzheimer-related amyloid-beta protein precursor (A beta PP)-processing in the human central nervous system. It has been hypothesized that amyloidogenic A beta PP-processing preferentially occurs in the regulated secretory pathway of neurons. To test this hypothesis we looked for correlations of A beta PP-derived molecules in cerebrospinal fluid (CSF) with chromogranin (Cg) derived peptides, representing the regulated secretion. Patients with Alzheimer's disease (AD, N = 32), multiple sclerosis (MS, N = 50), and healthy controls (N = 70) were enrolled. CSF was analyzed for the amyloid peptides A beta(1-42), A beta(x-42), A beta(x-40), A beta(x-38), alpha-cleaved soluble A beta PP (sA beta PP alpha), beta-cleaved soluble A beta PP (sA beta PP beta), and peptides derived from CgB and SgII (Secretogranin-II, CgC). We investigated CSF levels of the protease BACE1, which processes A beta PP into A beta, in relation to Cg-levels. Finally, we measured Cg levels in cell media from untreated and BACE1-inhibited SH-SY5Y human neuroblastoma cells. CSF Cg levels correlated to sA beta PP and A beta peptides in AD, MS, and controls, and to CSF BACE1. Cell medium from BACE1-inhibited cells had decreased CgB levels. These results suggest that a large part of A beta PP in the human central nervous system is processed in the regulated secretory pathway of neurons.
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| 6. |
- Mattsson, Niklas, 1979, et al.
(författare)
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Longitudinal cerebrospinal fluid biomarkers over four years in mild cognitive impairment.
- 2012
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Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908 .- 1387-2877. ; 30:4, s. 767-78
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Tidskriftsartikel (refereegranskat)abstract
- Cerebrospinal fluid (CSF) measurements of amyloid-β42 (Aβ42), total-tau (T-tau), and phosphorylated tau (P-tau) may be used to predict future Alzheimer's disease (AD) dementia in patients with mild cognitive impairment (MCI). The precise temporal development of these biomarkers in relation to clinical progression is unclear. Earlier studies have been hampered by short follow-up. In an MCI cohort, we selected 15 patients who developed AD (MCI-AD) and 15 who remained cognitively stable during 4 years of follow-up. CSF was sampled at three serial occasions from each patient and analyzed for Aβ peptides, the soluble amyloid-β protein precursor protein fragments sAβPPα and sAβPPβ, T-tau, P-tau, and chromogranin B, which is a protein linked to regulated neuronal secretion. We also measured, for the first time in MCI patients, an extended panel of Aβ peptides by matrix-assisted-laser-desorption/ionization time-of-flight mass spectrometry (MS). Most biomarkers were surprisingly stable over the four years with coefficients of variation below or close to 10%. However, MCI-AD patients decreased in CSF AβX₋₄₀ and chromogranin B concentrations, which may indicate a reduced number of functional neurons or synapses with disease progression. The MS Aβ peptide panel was more useful than any single Aβ peptide to identify MCI-AD patients already at baseline. Knowledge on these biomarkers and their trajectories may facilitate early diagnosis of AD and be useful in future clinical trials to track effects of disease modifying drugs.
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| 7. |
- Minta, Karolina, et al.
(författare)
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Brevican and Neurocan Peptides as Potential Cerebrospinal Fluid Biomarkers for Differentiation Between Vascular Dementia and Alzheimer's Disease
- 2021
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Ingår i: Journal of Alzheimer's disease : JAD. - 1387-2877 .- 1875-8908. ; 79:2, s. 729-741
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Brevican and neurocan are central nervous system-specific extracellular matrix proteoglycans. They are degraded by extracellular enzymes, such as metalloproteinases. However, their degradation profile is largely unexplored in cerebrospinal fluid (CSF).OBJECTIVE: The study aim was to quantify proteolytic peptides derived from brevican and neurocan in human CSF of patients with Alzheimer's disease (AD) and vascular dementia (VaD) compared with controls.METHODS: The first cohort consisted of 75 individuals including 25 patients with AD, 7 with mild cognitive impairment (MCI) diagnosed with AD upon follow-up, 10 patients with VaD or MCI diagnosed with VaD upon follow-up, and 33 healthy controls and cognitively stable MCI patients. In the second cohort, 31 individuals were included (5 AD patients, 14 VaD patients and 12 healthy controls). Twenty proteolytic peptides derived from brevican (n = 9) and neurocan (n = 11) were quantified using high-resolution parallel reaction monitoring mass spectrometry.RESULTS: In the first cohort, the majority of CSF concentrations of brevican and neurocan peptides were significantly decreased inVaDas compared withADpatients (AUC = 0.83.0.93, p≤0.05) and as compared with the control group (AUC = 0.79.0.87, p ≤ 0.05). In the second cohort, CSF concentrations of two brevican peptides (B87, B156) were significantly decreased in VaD compared with AD (AUC = 0.86.0.91, p ≤ 0.05) and to controls (AUC = 0.80.0.82, p ≤ 0.05), while other brevican and neurocan peptides showed a clear trend to be decreased in VaD compared with AD (AUC = 0.64.80, p > 0.05). No peptides differed between AD and controls.CONCLUSION: Brevican and neurocan peptides are potential diagnostic biomarkers for VaD, with ability to separate VaD from AD.
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| 8. |
- Rolandsson, Olov, et al.
(författare)
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Acute hyperglycemia induced by hyperglycemic clamp affects plasma Amyloid-β in type 2 diabetes
- 2024
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Ingår i: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 99:3, s. 1033-1046
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Tidskriftsartikel (refereegranskat)abstract
- Background: Individuals with type 2 diabetes (T2D) have an increased risk of cognitive symptoms and Alzheimer's disease (AD). Mis-metabolism with aggregation of amyloid-β peptides (Aβ) play a key role in AD pathophysiology. Therefore, human studies on Aβ metabolism and T2D are warranted.Objective: The objective of this study was to examine whether acute hyperglycemia affects plasma Aβ1-40 and Aβ1-42 concentrations in individuals with T2D and matched controls.Methods: Ten participants with T2D and 11 controls (median age, 69 years; range, 66-72 years) underwent hyperglycemic clamp and placebo clamp (saline infusion) in a randomized order, each lasting 4 hours. Aβ1-40, Aβ1-42, and insulin-degrading enzyme (IDE) plasma concentrations were measured in blood samples taken at 0 and 4 hours of each clamp. Linear mixed-effect regression models were used to evaluate the 4-hour changes in Aβ1-40 and Aβ1-42 concentrations, adjusting for body mass index, estimated glomerular filtration rate, and 4-hour change in insulin concentration.Results: At baseline, Aβ1-40 and Aβ1-42 concentrations did not differ between the two groups. During the hyperglycemic clamp, Aβ decreased in the control group, compared to the placebo clamp (Aβ1-40: p = 0.034, Aβ1-42: p = 0.020), IDE increased (p = 0.016) during the hyperglycemic clamp, whereas no significant changes in either Aβ or IDE was noted in the T2D group.Conclusions: Clamp-induced hyperglycemia was associated with increased IDE levels and enhanced Aβ40 and Aβ42 clearance in controls, but not in individuals with T2D. We hypothesize that insulin-degrading enzyme was inhibited during hyperglycemic conditions in people with T2D.
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| 9. |
- Åberg, Daniel, 1973, et al.
(författare)
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Increased Cerebrospinal Fluid Level of Insulin-like Growth Factor-II in Male Patients with Alzheimer's Disease
- 2015
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Ingår i: Journal of Alzheimers Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 48:3, s. 637-646
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Tidskriftsartikel (refereegranskat)abstract
- Background: Insulin-like growth factor-II (IGF-II) is important for brain development. Although IGF-II is abundant also in adult life, little is known of the role of IGF-II in Alzheimer's disease (AD). Objective and methods: This was a cross-sectional study of 60 consecutive patients under primary evaluation of cognitive impairment and 20 healthy controls. The patients had AD dementia or mild cognitive impairment (MCI) diagnosed with AD dementia upon follow-up (n = 32), stable MCI (SMCI, n = 13), or other dementias (n = 15). IGF-II, IGF-binding protein-1 (IGFBP-1), and IGFBP-2 were analyzed in serum and cerebrospinal fluid (CSF). Results: Levels of IGF-II, IGFBP-1, and IGFBP-2 were similar in all groups in the total study population. Gender-specific analyses showed that in men (n = 40), CSF IGF-II level was higher in AD compared to SMCI and controls (p < 0.01 and p < 0.05, respectively). Furthermore, CSF IGFBP-2 levelwas increased inADmen versus SMCI men (p < 0.01) and tended to be increased versus control men (p = 0.09). There were no between-group differences in women (n = 40). In the total study population (n = 80) as well as in men (n = 40), CSF levels of IGF-II and IGFBP-2 correlated positively with CSF levels of the AD biomarkers total-tau and phosphorylated tau protein. Conclusion: In men, but not women, in the early stages of AD, CSF IGF-II level was elevated, and CSF IGFBP-2 level tended to be increased, compared to healthy controls.
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| 10. |
- Alifier, Marek, et al.
(författare)
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Cardiac Surgery is Associated with Biomarker Evidence of Neuronal Damage.
- 2020
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Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908. ; 74:4, s. 1211-1220
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Tidskriftsartikel (refereegranskat)abstract
- Anesthesia and surgery is commonly associated with central nervous system sequelae and cognitive symptoms, which may be caused by neuronal injury. Neuronal injury can be monitored by plasma concentrations of the neuronal biomarkers tau and neurofilament light protein (NFL). Currently, there are no studies examining whether neuronal injury varies between surgical procedures.Our aim was to investigate if neuronal damage is more frequent after cardiac than after otolaryngeal surgery, as estimated by tau and NFL concentrations in plasma.Blood samples were drawn before, during, and after surgery and concentrations of tau, NFL, Aβ40, and Aβ42 were measured in 25 patients undergoing cardiac surgery (9 off-pump and 16 on-pump) and 26 patients undergoing otolaryngeal surgery.Tau increased during surgery (1752%, p=0.0001) and NFL rose seven days post-surgery (1090%, p<0.0001) in patients undergoing cardiac surgery; even more in patients on-pump than off-pump. No changes were observed in patients undergoing otolaryngeal surgery and only minor fluctuations were observed for Aβ40 and Aβ42.Cardiac surgery is associated with neuronal injury, which is aggravated by extracorporeal circulation. Analyses of NFL and tau in blood may guide development of surgical procedures to minimize neuronal damage, and may also be used in longitudinal clinical studies to assess the relationship of surgery with future neurocognitive impairment or dementia.
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