| 1. |
- Mattsson, Niklas, 1979, et al.
(författare)
-
CSF biomarkers and incipient Alzheimer disease in patients with mild cognitive impairment.
- 2009
-
Ingår i: JAMA : the journal of the American Medical Association. - : American Medical Association (AMA). - 1538-3598 .- 0098-7484. ; 302:4, s. 385-93
-
Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Small single-center studies have shown that cerebrospinal fluid (CSF) biomarkers may be useful to identify incipient Alzheimer disease (AD) in patients with mild cognitive impairment (MCI), but large-scale multicenter studies have not been conducted. OBJECTIVE: To determine the diagnostic accuracy of CSF beta-amyloid(1-42) (Abeta42), total tau protein (T-tau), and tau phosphorylated at position threonine 181 (P-tau) for predicting incipient AD in patients with MCI. DESIGN, SETTING, AND PARTICIPANTS: The study had 2 parts: a cross-sectional study involving patients with AD and controls to identify cut points, followed by a prospective cohort study involving patients with MCI, conducted 1990-2007. A total of 750 individuals with MCI, 529 with AD, and 304 controls were recruited by 12 centers in Europe and the United States. Individuals with MCI were followed up for at least 2 years or until symptoms had progressed to clinical dementia. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive and negative likelihood ratios (LRs) of CSF Abeta42, T-tau, and P-tau for identifying incipient AD. RESULTS: During follow-up, 271 participants with MCI were diagnosed with AD and 59 with other dementias. The Abeta42 assay in particular had considerable intersite variability. Patients who developed AD had lower median Abeta42 (356; range, 96-1075 ng/L) and higher P-tau (81; range, 15-183 ng/L) and T-tau (582; range, 83-2174 ng/L) levels than MCI patients who did not develop AD during follow-up (579; range, 121-1420 ng/L for Abeta42; 53; range, 15-163 ng/L for P-tau; and 294; range, 31-2483 ng/L for T-tau, P < .001). The area under the receiver operating characteristic curve was 0.78 (95% confidence interval [CI], 0.75-0.82) for Abeta42, 0.76 (95% CI, 0.72-0.80) for P-tau, and 0.79 (95% CI, 0.76-0.83) for T-tau. Cut-offs with sensitivity set to 85% were defined in the AD and control groups and tested in the MCI group, where the combination of Abeta42/P-tau ratio and T-tau identified incipient AD with a sensitivity of 83% (95% CI, 78%-88%), specificity 72% (95% CI, 68%-76%), positive LR, 3.0 (95% CI, 2.5-3.4), and negative LR, 0.24 (95% CI, 0.21-0.28). The positive predictive value was 62% and the negative predictive value was 88%. CONCLUSIONS: This multicenter study found that CSF Abeta42, T-tau, and P-tau identify incipient AD with good accuracy, but less accurately than reported from single-center studies. Intersite assay variability highlights a need for standardization of analytical techniques and clinical procedures.
|
|
| 2. |
- Buerger, Katharina, et al.
(författare)
-
CSF phosphorylated tau protein correlates with neocortical neurofibrillary pathology in Alzheimer's disease.
- 2006
-
Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 129:Pt 11, s. 3035-41
-
Tidskriftsartikel (refereegranskat)abstract
- Hyperphosphorylated tau protein (P-tau) in CSF is a core biomarker candidate of Alzheimer's disease. Hyperphosphorylation of tau is thought to lead to neurofibrillary changes, a neuropathological hallmark of this type of dementia. Currently, the question is unresolved whether CSF levels of P-tau reflect neurofibrillary changes within the brain of a patient with the illness. Twenty-six patients were included with intra-vitam CSF as well as post-mortem neuropathological data. In the CSF, P-tau phosphorylated at threonine 231 (P-tau231P) was analysed. Post-mortem, scores of neurofibrillary tangles (NFT) and neuritic plaques (NP) were assessed in frontal, temporal, parietal and hippocampal cortical areas. In the same cortical regions, load of hyperphosphorylated tau protein (HP-tau load) was determined. Concentrations of P-tau231P were measured in frontal cortex homogenates. We found significant correlations between CSF P-tau231P concentrations and scores of NFTs and HP-tau load in all neocortical regions studied. The score of NPs was correlated with CSF P-tau231P only within the frontal cortex. There was a correlation between P-tau231P in CSF and brain homogenates. These findings indicate that CSF P-tau231P may serve as an in vivo surrogate biomarker of neurofibrillary pathology in Alzheimer's disease.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Buerger, Katharina, et al.
(författare)
-
Validation of Alzheimer's disease CSF and plasma biological markers: the multicentre reliability study of the pilot European Alzheimer's Disease Neuroimaging Initiative (E-ADNI).
- 2009
-
Ingår i: Experimental gerontology. - : Elsevier BV. - 1873-6815 .- 0531-5565. ; 44:9, s. 579-85
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Alzheimer's Disease Neuroimaging Initiatives ("ADNI") aim to validate neuroimaging and biochemical markers of Alzheimer's disease (AD). Data of the pilot European-ADNI (E-ADNI) biological marker programme of cerebrospinal fluid (CSF) and plasma candidate biomarkers are reported. METHODS: Six academic EADC centres recruited 49 subjects (healthy controls, subjects with mild cognitive impairment (MCI) and AD). We measured CSF beta-amyloid 42 (CSF Abeta42), total tau-protein (t-tau), phosphorylated tau-proteins (P-tau181, P-tau231), plasma beta-amyloid 40 and 42 (Abeta40/Abeta42). Immediate fresh shipment was compared to freezing and later shipment on dry ice. RESULTS: CSF T-tau (fresh samples) was increased in AD versus controls (p=0.049), CSF Abeta42 (frozen samples) was decreased in MCI and AD (p=0.02), as well as plasma Abeta40 (fresh and frozen samples) in AD (p=0.049 and p=0.016). Pooled values of neurochemical parameters and ratios thereof were different between centres (p<0.005). Analysis of frozen samples yielded higher diagnostic accuracy than immediate fresh shipment with 100% (fresh: 100%) correctly classified in control subjects, 100% (78%) in MCI, 91% (91%) in AD. CONCLUSION: The use of frozen rather than fresh samples renders higher diagnostic accuracy within a multicentre context. We confirmed the feasibility of a multicentre AD biomarker programme for future clinical trials.
|
|
| 6. |
- Ewers, Michael, et al.
(författare)
-
Increased CSF-BACE 1 activity is associated with ApoE-epsilon 4 genotype in subjects with mild cognitive impairment and Alzheimer's disease.
- 2008
-
Ingår i: Brain : a journal of neurology. - : Oxford University Press (OUP). - 1460-2156. ; 131:Pt 5, s. 1252-8
-
Tidskriftsartikel (refereegranskat)abstract
- The Apolipoprotein (ApoE) epsilon 4 allele is a major genetic risk factor of Alzheimer's disease, and may affect the production of amyloid beta (A beta(1-42)). Recently, we have shown that beta-secretase (BACE 1) activity can be reliably detected within the brain and human CSF. Here, we have examined an association between the ApoE genotype and CSF-levels of BACE 1 activity in Alzheimer's disease and mild cognitive impairment (MCI). A total of 148 subjects were included: 60 Alzheimer's disease patients, 51 MCI subjects and 37 elderly healthy controls. The CSF-levels of A beta(1-42), BACE 1 activity and BACE protein were measured in all of these subjects. The differences between ApoE-epsilon 4 carriers and ApoE-epsilon 4 non-carriers in these CSF-based measures were determined controlling for gender, age and MMSE score. The ApoE-epsilon 4 genotype was associated with increased BACE 1 activity in both Alzheimer's disease (P = 0.03) and MCI (P = 0.04) subjects. Levels of A beta(1-42) were decreased in ApoE-epsilon 4 carriers in MCI (P = 0.004) but not Alzheimer's disease subjects. This study is the first to demonstrate the association between ApoE-epsilon 4 and CSF-BACE 1 activity in MCI and Alzheimer's disease subjects. The assessment of BACE 1 in CSF may provide a sensitive measure to detect in vivo alterations in the amyloidogenic processing potentially modified by the ApoE genotype.
|
|
| 7. |
|
|
| 8. |
- Hampel, Harald, et al.
(författare)
-
Lithium trial in Alzheimer's disease : a randomized, single-blind, placebo-controlled, multicenter 10-week study
- 2009
-
Ingår i: Journal of Clinical Psychiatry. - 0160-6689 .- 1555-2101. ; 70:6, s. 922-931
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Lithium, a first-line drug for the treatment of bipolar depression, has recently been shown to regulate glycogen synthase kinase-3 (GSK-3), a kinase that is involved in the phosphorylation of the tau protein. Since hyperphosphorylation of tau is a core pathological feature in Alzheimer's disease, lithium-induced inhibition of GSK-3 activity may have therapeutic effects in Alzheimer's disease. In the current study, we tested the effect of short-term lithium treatment in patients with Alzheimer's disease. METHOD: A total of 71 patients with mild Alzheimer's disease (Mini-Mental State Examination score > or = 21 and < or = 26) were successfully randomly assigned to placebo (N = 38) or lithium treatment (N = 33) at 6 academic expert memory clinics. The 10-week treatment included a 6-week titration phase to reach the target serum level of lithium (0.5-0.8 mmol/L). The primary outcome measures were cerebrospinal fluid (CSF) levels of phosphorylated tau (p-tau) and GSK-3 activity in lymphocytes. Secondary outcome measures were CSF concentration of total tau and beta-amyloid(1-42) (Abeta(1-42)), plasma levels of Abeta(1-42), Alzheimer's Disease Assessment Scale (ADAS)-Cognitive summary scores, MMSE, and Neuropsychiatric Inventory (NPI). Patients were enrolled in the study from November 2004 to July 2005. RESULTS: No treatment effect on GSK-3 activity or CSF-based biomarker concentrations (P > .05) was observed. Lithium treatment did not lead to change in global cognitive performance as measured by the ADAS-Cog subscale (P = .11) or in depressive symptoms. CONCLUSIONS: The current results do not support the notion that lithium treatment may lead to reduced hyperphosphorylation of tau protein after a short 10-week treatment in the Alzheimer's disease target population.
|
|
| 9. |
- Yamamori, Hidenaga, et al.
(författare)
-
Tau in cerebrospinal fluid: a sensitive sandwich enzyme-linked immunosorbent assay using tyramide signal amplification.
- 2007
-
Ingår i: Neuroscience letters. - : Elsevier BV. - 0304-3940. ; 418:2, s. 186-9
-
Tidskriftsartikel (refereegranskat)abstract
- Tau in cerebrospinal fluid (CSF) has been proposed as a diagnostic marker for Alzheimer's disease (AD). This paper presents a new sensitive sandwich ELISA allowing quantitation of tau from 8 microl CSF/well. A human specific monoclonal tau antibody HT7 was used as a capture antibody and a mixture of polyclonal tau antibodies, 92e and R134d was used as reporter antibodies. Tyramide signal amplification (TSA) technology was used in the last step to increase the sensitivity. With this TSA-ELISA, the lowest detection limit for tau was 14.3 pg/ml. Tau levels in CSF were found to be increased in AD patients (807+/-304 pg/ml, p<0.001) compared with controls (252+/-94 pg/ml). Thirty-five of 38 AD cases (92% sensitivity) yielded signals greater than cutoff, while only 1 of 38 control cases (97% specificity) was greater. A highly significant correlation was found between this assay and a commonly used kit, INNOTEST hTAU Antigen.
|
|
| 10. |
|
|
