| 61. |
- Janelidze, Shorena, et al.
(författare)
-
Plasma beta-amyloid in Alzheimer's disease and vascular disease
- 2016
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
-
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.
|
|
| 62. |
- Janelidze, Shorena, et al.
(författare)
-
Plasma P-tau181 in Alzheimer's disease: relationship to other biomarkers, differential diagnosis, neuropathology and longitudinal progression to Alzheimer's dementia
- 2020
-
Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 26, s. 379-386
-
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.
|
|
| 63. |
- Janelidze, Shorena, et al.
(författare)
-
Plasma Phosphorylated Tau 217 and Aβ42/40 to Predict Early Brain Aβ Accumulation in People Without Cognitive Impairment
- 2024
-
Ingår i: JAMA NEUROLOGY. - 2168-6149 .- 2168-6157.
-
Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE Phase 3 trials of successful antiamyloid therapies in Alzheimer disease (AD) have demonstrated improved clinical efficacy in people with less severe disease. Plasma biomarkers will be essential for efficient screening of participants in future primary prevention clinical trials testing antiamyloid therapies in cognitively unimpaired (CU) individuals with initially low brain beta-amyloid (A beta) levels who are at high risk of accumulating A beta. OBJECTIVE To investigate if combining plasma biomarkers could be useful in predicting subsequent development of A beta pathology in CU individuals with subthreshold brain A beta levels (defined as A beta levels <40 Centiloids) at baseline. DESIGN, SETTING, AND PARTICIPANTS This was a longitudinal study including Swedish BioFINDER-2 (enrollment 2017-2022) and replication in 2 independent cohorts, the Knight Alzheimer Disease Research Center (Knight ADRC; enrollment 1988 and 2019) and Swedish BioFINDER-1 (enrollment 2009-2015). Included for analysis was a convenience sample of CU individuals with baseline plasma phosphorylated tau 217 (p-tau217) and A beta 42/40 assessments and A beta assessments with positron emission tomography (A beta-PET) or cerebrospinal fluid (CSF) A beta 42/40. Data were analyzed between April 2023 and May 2024. EXPOSURES Baseline plasma levels of A beta 42/40, p-tau217, the ratio of p-tau217 to nonphosphorylated tau (%p-tau217), p-tau231, and glial fibrillary acidic protein (GFAP). MAIN OUTCOMES AND MEASURES Cross-sectional and longitudinal PET and CSF measures of brain A beta pathology. RESULTS This study included 495 (BioFINDER-2), 283 (Knight ADRC), and 205 (BioFINDER-1) CU participants. In BioFINDER-2, the mean (SD) age was 65.7 (14.4) with 261 females (52.7%). When detecting abnormal CSF A beta-status, a combination of plasma %p-tau217 and A beta 42/40 showed better performance (area under the curve = 0.949; 95% CI, 0.929-0.970; P <.02) than individual biomarkers. In CU participants with subthreshold baseline A beta-PET, baseline plasma %p-tau217 and A beta 42/40 levels were significantly associated with baseline A beta-PET (n = 384) and increases in A beta-PET over time (n = 224). Associations of plasma %p-tau217 and A beta 42/40 and their interaction with baseline A beta-PET (%p-tau217: beta = 2.77; 95% CI, 1.84-3.70; A beta 42/40: beta = -1.64; 95% CI, -2.53 to -0.75; %p-tau217 x A beta 42/40: beta = -2.14; 95% CI, -2.79 to -1.49; P < .001) and longitudinal A beta-PET (%p-tau217: beta = 0.67; 95% CI, 0.48-0.87; A beta 42/40: beta = -0.33; 95% CI, -0.51 to -0.15; %p-tau217 x A beta 42/40: beta = -0.31; 95% CI, -0.44 to -0.18; P < .001) were also significant in the models combining the 2 baseline biomarkers as predictors. Similarly, baseline plasma p-tau217 and A beta 42/40 were independently associated with longitudinal A beta-PET in Knight ADRC (%p-tau217: beta = 0.71; 95% CI, 0.26-1.16; P = .002; A beta 42/40: beta = -0.74; 95% CI, -1.26 to -0.22; P = .006) and longitudinal CSF A beta 42/40 in BioFINDER-1 (p-tau217: beta = -0.0003; 95% CI, -0.0004 to -0.0001; P = .01; A beta 42/40: beta = 0.0004; 95% CI, 0.0002-0.0006; P < .001) in CU participants with subthreshold A beta levels at baseline. Plasma p-tau231 and GFAP did not provide any clear independent value. CONCLUSIONS AND RELEVANCE Results of this cohort study suggest that combining plasma p-tau217and A beta 42/40 levels could be useful for predicting development of A beta pathology in people with early stages of subthreshold A beta accumulation. These biomarkers might thus facilitate screening of participants for future primary prevention trials.
|
|
| 64. |
- Janelidze, Shorena, et al.
(författare)
-
Towards a unified protocol for handling of CSF before β-amyloid measurements
- 2019
-
Ingår i: Alzheimer's Research and Therapy. - : Springer Science and Business Media LLC. - 1758-9193. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Widespread implementation of Alzheimer's disease biomarkers in routine clinical practice requires the establishment of standard operating procedures for pre-analytical handling of cerebrospinal fluid (CSF). Methods: Here, CSF collection and storage protocols were optimized for measurements of β-amyloid (Aβ). We investigated the effects of (1) storage temperature, (2) storage time, (3) centrifugation, (4) sample mixing, (5) blood contamination, and (6) collection gradient on CSF levels of Aβ. For each study participant, we used fresh CSF directly collected into a protein low binding (LoB) tube that was analyzed within hours after lumbar puncture (LP) as standard of truth. Aβ42 and Aβ40 were measured in de-identified CSF samples using EUROIMMUN and Mesoscale discovery assays. Results: CSF Aβ42 and Aβ40 were stable for at least 72 h at room temperature (RT), 1 week at 4 °C, and 2 weeks at - 20 °C and - 80 °C. Centrifugation of non-blood-contaminated CSF or mixing of samples before the analysis did not affect Aβ levels. Addition of 0.1-10% blood to CSF that was stored at RT without centrifugation led to a dose- and time-dependent decrease in Aβ42 and Aβ40, while Aβ42/Aβ40 did not change. The effects of blood contamination were mitigated by centrifugation and/or storage at 4 °C or - 20 °C. Aβ levels did not differ between the first to fourth 5-ml portions of CSF. Conclusions: CSF can be stored for up to 72 h at RT, 1 week at 4 °C, or at least 2 weeks at either - 20 °C or - 80 °C before Aβ measurements. Centrifugation of fresh non-blood-contaminated CSF after LP, or mixing before analysis, is not required. In case of visible blood contamination, centrifugation and storage at 4 °C or - 20 °C is recommended. After discarding the first 2 ml, any portion of up to 20 ml of CSF is suitable for Aβ analysis. These findings will be important for the development of a clinical routine protocol for pre-analytical handling of CSF.
|
|
| 65. |
- Jansen, Willemijn J, et al.
(författare)
-
Association of Cerebral Amyloid-β Aggregation With Cognitive Functioning in Persons Without Dementia.
- 2018
-
Ingår i: JAMA psychiatry. - : American Medical Association (AMA). - 2168-6238 .- 2168-622X. ; 75:1, s. 84-95
-
Tidskriftsartikel (refereegranskat)abstract
- Cerebral amyloid-β aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials.To investigate whether amyloid-β aggregation is associated with cognitive functioning in persons without dementia.This cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017.Global cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score ≤27 or memory z score≤-1.28) and to assess whether this association was moderated by age, sex, educational level, or apolipoprotein E genotype.Among 2908 persons with normal cognition (mean [SD] age, 67.4 [12.8] years), amyloid positivity was associated with low memory scores after age 70 years (mean difference in amyloid positive vs negative, 4% [95% CI, 0%-7%] at 72 years and 21% [95% CI, 10%-33%] at 90 years) but was not associated with low MMSE scores (mean difference, 3% [95% CI, -1% to 6%], P=.16). Among 4133 patients with MCI (mean [SD] age, 70.2 [8.5] years), amyloid positivity was associated with low memory (mean difference, 16% [95% CI, 12%-20%], P<.001) and low MMSE (mean difference, 14% [95% CI, 12%-17%], P<.001) scores, and this association decreased with age. Low cognitive scores had limited utility for screening of amyloid positivity in persons with normal cognition and those with MCI. In persons with normal cognition, the age-related increase in low memory score paralleled the age-related increase in amyloid positivity with an intervening period of 10 to 15 years.Although low memory scores are an early marker of amyloid positivity, their value as a screening measure for early AD among persons without dementia is limited.
|
|
| 66. |
- Jansen, Willemijn J, et al.
(författare)
-
Prevalence Estimates of Amyloid Abnormality Across the Alzheimer Disease Clinical Spectrum.
- 2022
-
Ingår i: JAMA neurology. - : American Medical Association (AMA). - 2168-6157 .- 2168-6149. ; 79:3, s. 228-243
-
Tidskriftsartikel (refereegranskat)abstract
- One characteristic histopathological event in Alzheimer disease (AD) is cerebral amyloid aggregation, which can be detected by biomarkers in cerebrospinal fluid (CSF) and on positron emission tomography (PET) scans. Prevalence estimates of amyloid pathology are important for health care planning and clinical trial design.To estimate the prevalence of amyloid abnormality in persons with normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia and to examine the potential implications of cutoff methods, biomarker modality (CSF or PET), age, sex, APOE genotype, educational level, geographical region, and dementia severity for these estimates.This cross-sectional, individual-participant pooled study included participants from 85 Amyloid Biomarker Study cohorts. Data collection was performed from January 1, 2013, to December 31, 2020. Participants had normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia. Normal cognition and subjective cognitive decline were defined by normal scores on cognitive tests, with the presence of cognitive complaints defining subjective cognitive decline. Mild cognitive impairment and clinical AD dementia were diagnosed according to published criteria.Alzheimer disease biomarkers detected on PET or in CSF.Amyloid measurements were dichotomized as normal or abnormal using cohort-provided cutoffs for CSF or PET or by visual reading for PET. Adjusted data-driven cutoffs for abnormal amyloid were calculated using gaussian mixture modeling. Prevalence of amyloid abnormality was estimated according to age, sex, cognitive status, biomarker modality, APOE carrier status, educational level, geographical location, and dementia severity using generalized estimating equations.Among the 19097 participants (mean [SD] age, 69.1 [9.8] years; 10148 women [53.1%]) included, 10139 (53.1%) underwent an amyloid PET scan and 8958 (46.9%) had an amyloid CSF measurement. Using cohort-provided cutoffs, amyloid abnormality prevalences were similar to 2015 estimates for individuals without dementia and were similar across PET- and CSF-based estimates (24%; 95% CI, 21%-28%) in participants with normal cognition, 27% (95% CI, 21%-33%) in participants with subjective cognitive decline, and 51% (95% CI, 46%-56%) in participants with mild cognitive impairment, whereas for clinical AD dementia the estimates were higher for PET than CSF (87% vs 79%; mean difference, 8%; 95% CI, 0%-16%; P=.04). Gaussian mixture modeling-based cutoffs for amyloid measures on PET scans were similar to cohort-provided cutoffs and were not adjusted. Adjusted CSF cutoffs resulted in a 10% higher amyloid abnormality prevalence than PET-based estimates in persons with normal cognition (mean difference, 9%; 95% CI, 3%-15%; P=.004), subjective cognitive decline (9%; 95% CI, 3%-15%; P=.005), and mild cognitive impairment (10%; 95% CI, 3%-17%; P=.004), whereas the estimates were comparable in persons with clinical AD dementia (mean difference, 4%; 95% CI, -2% to 9%; P=.18).This study found that CSF-based estimates using adjusted data-driven cutoffs were up to 10% higher than PET-based estimates in people without dementia, whereas the results were similar among people with dementia. This finding suggests that preclinical and prodromal AD may be more prevalent than previously estimated, which has important implications for clinical trial recruitment strategies and health care planning policies.
|
|
| 67. |
- Johansson, Maurits, et al.
(författare)
-
Apathy and anxiety are early markers of Alzheimer's disease
- 2020
-
Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 85, s. 74-82
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, we investigated associations between neuropsychiatric symptoms (i.e., apathy, anxiety, and depression) and cerebral atrophy, white matter lesions (WML), beta-amyloid (A beta) deposition, and cognitive decline in a nondemented sample. 104 cognitively unimpaired and 53 subjects with mild cognitive impairment were followed for up to 4 years within the Swedish BioFINDER study. Neuropsychiatric assessments included the Hospital Anxiety and Depression Scale and the Apathy Evaluation Scale. Magnetic resonance imaging and F-18-flutemetamol-positron emission tomography quantified brain atrophy, WML, and A beta deposition. Mini-Mental State Examination assessed longitudinal global cognition. Regression analyses were used to test for associations. Apathy and anxiety were shown related to A beta deposition and predicted cognitive decline. Anxiety also interacted with amyloid status to predict faster cognitive deterioration. Apathy was further related to frontotemporal and subcortical atrophy, as well as WML. To conclude, the associations between apathy and anxiety with A beta deposition and cognitive decline point to these symptoms as early clinical manifestations of Alzheimer's disease. (C) 2019 Elsevier Inc. All rights reserved.
|
|
| 68. |
- Johansson, Maurits, et al.
(författare)
-
Development of Apathy, Anxiety, and Depression in Cognitively Unimpaired Older Adults : Effects of Alzheimer's Disease Pathology and Cognitive Decline
- 2022
-
Ingår i: Biological Psychiatry. - : Elsevier BV. - 0006-3223 .- 1873-2402. ; 92:1, s. 34-43
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The impact of Alzheimer's disease (AD) pathology and cognitive deficits on longitudinal neuropsychiatric symptoms is unclear, especially in early disease stages. Methods: Cognitively unimpaired older adults (N = 356) enrolled in the prospective Swedish BioFINDER study were examined. Neuropsychiatric assessments encompassed the Apathy Evaluation Scale and the Hospital Anxiety and Depression Scale, performed biennially (together with tests of global cognition) for up to 8 years. Biomarkers were measured in cerebrospinal fluid or plasma at baseline. Magnetic resonance imaging quantified white matter lesions. We used linear mixed-effect models to test associations between baseline AD biomarkers (for amyloid-β [Aβ], tau, and neurodegeneration) and white matter lesions with longitudinal neuropsychiatric symptoms (apathy, anxiety, and depressive symptoms). We also tested associations between changes in cognition and changes in neuropsychiatric symptoms. Finally, we tested if change in cognition mediated the effects of different brain pathologies on neuropsychiatric symptoms. Results: Aβ pathology at baseline was associated with increasing levels of apathy (β = −0.284, p =.005) and anxiety (β = −0.060, p =.011) longitudinally. More rapid decline of cognition over time was related to increasing levels of apathy. The effects of baseline Aβ pathology on longitudinal apathy were partly mediated by changes in cognitive performance (proportion mediated 23%). Conclusions: Aβ pathology may drive the development of both apathy and anxiety in very early stages of AD, largely independent of cognitive change. The effect of Aβ on apathy is only partially conveyed by worse cognition. Together, these findings highlight certain neuropsychiatric symptoms as early manifestations of AD.
|
|
| 69. |
- Johansson, Maurits, et al.
(författare)
-
Mild behavioral impairment and its relation to tau pathology in preclinical Alzheimer's disease
- 2021
-
Ingår i: Translational Psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- Mild behavioral impairment (MBI) is suggested as risk marker for neurodegenerative diseases, such as Alzheimer's disease (AD). Recently, pathologic tau deposition in the brain has been shown closely related to clinical manifestations, such as cognitive deficits. Yet, associations between tau pathology and MBI have rarely been investigated. It is further debated if MBI precedes cognitive deficits in AD. Here, we explored potential mechanisms by which MBI is related to AD, this by studying associations between MBI and tau in preclinical AD. In all, 50 amyloid-beta -positive cognitively unimpaired subjects (part of the BioFINDER-2 study) underwent MBI-checklist (MBI-C) to assess MBI, and the Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog) delayed word recall (ADAS-DR) to assess episodic memory. Early tau pathology was determined using tau-PET ([F-18]RO948 retention in entorhinal cortex/hippocampus) and cerebrospinal fluid (CSF) P-tau(181). Regression models were used to test for associations. We found that higher tau-PET signal in the entorhinal cortex/hippocampus and CSF P-tau(181) levels were associated with higher MBI-C scores (beta =0.010, SE=0.003, p=0.003 and beta =1.263, SE=0.446, p=0.007, respectively). When MBI-C and ADAS-DR were entered together in the regression models, tau-PET (beta =0.009, p=0.009) and CSF P-tau(181) (beta =0.408, p=0.006) were predicted by MBI-C, but not ADAS-DR. We conclude that in preclinical AD, MBI is associated with tau independently from memory deficits. This denotes MBI as an important early clinical manifestation related to tau pathology in AD.
|
|
| 70. |
- Johansson, Maurits, et al.
(författare)
-
Psychometric testing of a Swedish version of the Apathy Evaluation Scale
- 2017
-
Ingår i: Nordic Journal of Psychiatry. - : Informa UK Limited. - 0803-9488 .- 1502-4725. ; 71:6, s. 477-484
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Apathy, a prevalent and clinically relevant symptom in neurodegenerative disease, is often evaluated by the instrument Apathy Evaluation Scale (AES). However, this instrument has not been translated into Swedish, halting clinical and research efforts. Furthermore, previous studies lack analyses of some basic properties, such as the legitimacy of a total score, or have analysed dimensionality by questionable methods.Aim: To translate and psychometrically evaluate a Swedish version of the AES.Method: The AES was translated, and its psychometric properties were tested in the Swedish BioFINDER study, including cognitively well elderly, and subjects with mild cognitive or parkinsonian symptoms. Psychometric analyses were conducted according to classical test theory (CTT) and aimed to resemble those performed in the English original study by Marin etal. in 1991. Dimensionality was additionally analysed on a matrix of polychoric correlations and parallel analyses.Results: Data indicate that the Swedish AES performs satisfactorily regarding data completeness, scaling assumptions, targeting, and reliability. Principal component analyses (with parallel analysis) of polychoric correlation matrices identified a single component. Convergent and discriminative validity correlations accorded with a priori expectations.Conclusions: The study provides initial support that this Swedish AES performs similarly to the English original, and exhibits acceptable psychometric properties according to CTT, including supported unidimensionality, and may be adopted for use in clinical and research settings.
|
|
