scholarly journals Cerebro-spinal fluid biomarker levels: phosphorylated tau (T) and total tau (N) as markers for rate of progression in Alzheimer’s disease

BMC Neurology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Carina Wattmo ◽  
Kaj Blennow ◽  
Oskar Hansson

Abstract Background We investigated the potential associations between cerebro-spinal fluid (CSF) levels of phosphorylated tau (P-tau) and total tau (T-tau) with short-term response to cholinesterase inhibitor (ChEI) treatment, longitudinal outcome and progression rates in Alzheimer’s disease (AD). Methods This prospective, observational study included 129 participants clinically diagnosed with mild-to-moderate AD, who underwent a lumbar puncture. The CSF biomarkers amyloid-β1–42 (Aβ42), P-tau and T-tau were analysed with xMAP technology. Cognitive, global, instrumental and basic activities of daily living (ADL) capacities at the start of ChEI therapy and semi-annually over 3 years were evaluated. Results All patients had abnormal Aβ42 (A+). Fifty-eight individuals (45%) exhibited normal P-tau and T-tau (A+ T– (N)–), 12 (9%) abnormal P-tau/normal T-tau (A+ T+ (N)–), 17 (13%) normal P-tau/abnormal T-tau (A+ T– (N)+) and 42 (33%) abnormal P-tau and T-tau (A+ T+ (N)+). The participants with A+ T+ (N)+ were younger than A+ T– (N)+ at the estimated onset of AD and the initiation of ChEIs. The proportion of 6-month responders to ChEI and deterioration/year after start of treatment did not differ between the AT(N) profiles in any scales. A higher percentage of globally improved/unchanged patients was exhibited in the A+ T– (N)– group after 12, 30 and 36 months of ChEI therapy but not at other assessments. In apolipoprotein E (APOE) ε4-carriers, linear relationships were found between greater cognitive decline/year and higher tau; Mini-Mental State Examination score – T-tau (rs = − 0.257, p = 0.014) and Alzheimer’s Disease Assessment Scale–cognitive subscale – P-tau (rs = − 0.242, p = 0.022). A correlation between faster progression in instrumental ADL (IADL) and higher T-tau was also detected (rs = − 0.232, p = 0.028). These associations were not demonstrated in non-ε4-carriers. Conclusions Younger age and faster global deterioration were observed in AD patients with pathologic tau and neurodegeneration, whereas more rapid cognitive and IADL decline were related to higher P-tau or T-tau in APOE ε4-carriers only. The results might indicate an association between more pronounced tau pathology/neuronal injury and the APOE ε4-allele leading to a worse prognosis. Our findings showed that the AT(N) biomarker profiles have limited utility to predict AD progression rates and, thus, measure change and interpreting outcomes from clinical trials of future therapies.

2020 ◽  
Author(s):  
Bin Jiao ◽  
Hui Liu ◽  
Lina Guo ◽  
Xinxin Liao ◽  
Yafang Zhou ◽  
...  

Abstract BackgroundRobust studies have focused on blood-based biomarkers for diagnosis of Alzheimer’s disease (AD), while the results were still controversary and failed verified in different cohorts. The aim of this study was to detect the levels of plasma amyloid β (Aβ), total tau (t-tau), and neurofilament light chain (NfL) in patients with AD and cognitive normal (CN) subjects, and clarify their associations with Aβ, t-tau, and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF) as well as brain amyloid PET, and calculate the diagnostic efficiency of these characteristics regarding AD.Methods Plasma Aβ42, Aβ40, t-tau and NfL levels were detected by single-molecule array (Simoa) in 379 AD patients and 153 CN subjects. Additionally, lumbar puncture was conducted in 125 AD patients to detect Aβ42, Aβ40, t-tau, and p-tau levels. Brain amyloid PET was performed in 52 AD patients to identify brain amyloid deposition levels. Correlation analysis were performed between plasma biomarkers and typical biomarkers of AD, including CSF core biomarkers and amyloid PET burden. Finally, the diagnostic value of plasma biomarkers was further assessed by receiver operating characteristic (ROC) curve.ResultsCompared with the CN group, plasma Aβ42 and Aβ42/Aβ40 levels were significantly lower in AD patients, while Aβ40, t-tau and NfL levels were higher in AD patients. Among the AD patients, plasma Aβ42 was positively correlated with CSF Aβ42 (r = 0.195, p = 0.03) and Aβ42/Aβ40 (r = 0.208, p = 0.04). Moreover, plasma NfL was positively correlated with age, disease course and severity. The diagnostic model with combined plasma Aβ42, t-tau, and NfL levels controlled for age and APOE genotype showed the best performance to identify AD (area under the curve (AUC) = 0.88, sensitivity = 82.84%, specificity = 81.69%, cutoff value = 0.64).ConclusionsTrends revealed by core biomarkers were generally consistent in AD patients’ plasma and CSF. Combining plasma biomarkers can provide comparatively high AD diagnostic performance.


2019 ◽  
Author(s):  
Katheryn A.Q. Cousins ◽  
David J. Irwin ◽  
David A. Wolk ◽  
Edward B. Lee ◽  
Leslie M.J. Shaw ◽  
...  

AbstractUnder the ATN framework, cerebrospinal fluid analytes provide evidence of the presence or absence of Alzheimer’s disease pathological hallmarks: amyloid plaques (A), phosphorylated tau (T), and accompanying neurodegeneration (N). Still, differences in cerebrospinal fluid levels across amnestic and non-amnestic variants or due to co-occurring pathologies might lead to misdiagnoses. We assess the diagnostic accuracy of cerebrospinal fluid markers for amyloid, tau, and neurodegeneration in an autopsy cohort of 118 Alzheimer’s disease patients (98 amnestic; 20 non-amnestic) and 64 frontotemporal lobar degeneration patients (five amnestic; 59 non-amnestic). We calculated between-group differences in cerebrospinal fluid concentrations of amyloid-β1–42 peptide, tau protein phosphorylated at threonine 181, total tau, and the ratio of phosphorylated tau to amyloid-β1–42. Results show that non-amnestic Alzheimer’s disease patients were less likely to be correctly classified under the ATN framework using independent, published biomarker cutoffs for positivity. Amyloid-β1–42 did not differ between amnestic and non-amnestic Alzheimer’s disease, and receiver operating characteristic curve analyses indicated that amyloid-β1–42 was equally effective in discriminating both groups from frontotemporal lobar degeneration. However, cerebrospinal fluid concentrations of phosphorylated tau, total tau, and the ratio of phosphorylated tau to amyloid-β1–42 were significantly lower in non-amnestic compared to amnestic Alzheimer’s disease patients. Receiver operating characteristic curve analyses for these markers showed reduced area under the curve when discriminating non-amnestic Alzheimer’s disease from frontotemporal lobar degeneration, compared to discrimination of amnestic Alzheimer’s disease from frontotemporal lobar degeneration. In addition, the ATN framework was relatively insensitive to frontotemporal lobar degeneration, and these patients were likely to be classified as having normal biomarkers or biomarkers suggestive of primary Alzheimer’s disease pathology. We conclude that amyloid-β1–42 maintains high sensitivity to A status, although with lower specificity, and this single biomarker provides better sensitivity to non-amnestic Alzheimer’s disease than either the ATN framework or the phosphorylated-tau/amyloid-β1–42 ratio. In contrast, T and N status biomarkers differed between amnestic and non-amnestic Alzheimer’s disease; standard cutoffs for phosphorylated tau and total tau may thus result in misclassifications for non-amnestic Alzheimer’s patients. Consideration of clinical syndrome may help improve the accuracy of ATN designations for identifying true non-amnestic Alzheimer’s disease.Abbreviated SummaryCousins et al. assess the 2018 ATN framework and find that non-amnestic patients with Alzheimer’s disease (AD) have lower cerebrospinal fluid (CSF) phosphorylated tau and total tau than amnestic AD, while CSF amyloid-β accurately stratifies both non-amnestic and amnestic AD from frontotemporal lobar degeneration.


2021 ◽  
Vol 13 ◽  
Author(s):  
Bin Jiao ◽  
Hui Liu ◽  
Lina Guo ◽  
Xinxin Liao ◽  
Yafang Zhou ◽  
...  

Background: Alzheimer's disease (AD) is the most common type of dementia and has no effective treatment to date. It is essential to develop a minimally invasive blood-based biomarker as a tool for screening the general population, but the efficacy remains controversial. This cross-sectional study aimed to evaluate the ability of plasma biomarkers, including amyloid β (Aβ), total tau (t-tau), and neurofilament light chain (NfL), to detect probable AD in the South Chinese population.Methods: A total of 277 patients with a clinical diagnosis of probable AD and 153 healthy controls with normal cognitive function (CN) were enrolled in this study. The levels of plasma Aβ42, Aβ40, t-tau, and NfL were detected using ultra-sensitive immune-based assays (SIMOA). Lumbar puncture was conducted in 89 patients with AD to detect Aβ42, Aβ40, t-tau, and phosphorylated (p)-tau levels in the cerebrospinal fluid (CSF) and to evaluate the consistency between plasma and CSF biomarkers through correlation analysis. Finally, the diagnostic value of plasma biomarkers was further assessed by constructing a receiver operating characteristic (ROC) curve.Results: After adjusting for age, sex, and the apolipoprotein E (APOE) alleles, compared to the CN group, the plasma t-tau, and NfL were significantly increased in the AD group (p < 0.01, Bonferroni correction). Correlation analysis showed that only the plasma t-tau level was positively correlated with the CSF t-tau levels (r = 0.319, p = 0.003). The diagnostic model combining plasma t-tau and NfL levels, and age, sex, and APOE alleles, showed the best performance for the identification of probable AD [area under the curve (AUC) = 0.89, sensitivity = 82.31%, specificity = 83.66%].Conclusion: Blood biomarkers can effectively distinguish patients with probable AD from controls and may be a non-invasive and efficient method for AD pre-screening.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mari Aksnes ◽  
Ann Tiiman ◽  
Trine Holt Edwin ◽  
Lars Terenius ◽  
Nenad Bogdanović ◽  
...  

Accurate biomarkers of Alzheimer’s disease (AD) are essential for early diagnosis and intervention. Available biomarkers are not sufficient to permit the monitoring of AD progression over time, and additional biomarkers are required. Measures of aggregated amyloid-β (Aβ) could be useful biomarkers for AD. Here, we investigate whether levels of Thioflavin-T (ThT) positive amyloid aggregates, i.e., nanoplaques, in cerebrospinal fluid (CSF) could serve as useful biomarkers for AD. One-hundred and eighteen memory clinic patients were AT(N) classified, and CSF nanoplaque concentrations were compared between patients on the “Alzheimer’s continuum” (A+ patients) and patients with “Normal AD biomarkers” or “Non-AD pathologic change” (A− patients). CSF nanoplaque concentrations and sizes were quantified using the novel ThT-Fluorescence Correlation Spectroscopy (ThT-FCS) assay, and core biomarkers (Aβ42, total tau and phosphorylated tau) were determined by enzyme-linked immunosorbent assays. We investigated the association between nanoplaque concentrations and core biomarkers, and the diagnostic value of nanoplaque levels. Nanoplaque levels were increased in A+ patients compared to A− patients. Nanoplaque concentrations were negatively associated with Aβ42, but not related to total tau or phosphorylated tau measures. Quantification of nanoplaques did not improve the classification of patients on the Alzheimer’s continuum compared to the core biomarkers alone. Dynamic changes in nanoplaques concentration and size throughout AD stages should be explored in longitudinal studies.


2021 ◽  
pp. 174077452110344
Author(s):  
Michelle M Nuño ◽  
Joshua D Grill ◽  
Daniel L Gillen ◽  

Background/Aims: The focus of Alzheimer’s disease studies has shifted to earlier disease stages, including mild cognitive impairment. Biomarker inclusion criteria are often incorporated into mild cognitive impairment clinical trials to identify individuals with “prodromal Alzheimer’s disease” to ensure appropriate drug targets and enrich for participants likely to develop Alzheimer’s disease dementia. The use of these eligibility criteria may affect study power. Methods: We investigated outcome variability and study power in the setting of proof-of-concept prodromal Alzheimer’s disease trials that incorporate cerebrospinal fluid levels of total tau (t-tau) and phosphorylated (p-tau) as primary outcomes and how differing biomarker inclusion criteria affect power. We used data from the Alzheimer’s Disease Neuroimaging Initiative to model trial scenarios and to estimate the variance and within-subject correlation of total and phosphorylated tau. These estimates were then used to investigate the differences in study power for trials considering these two surrogate outcomes. Results: Patient characteristics were similar for all eligibility criteria. The lowest outcome variance and highest within-subject correlation were obtained when phosphorylated tau was used as an eligibility criterion, compared to amyloid beta or total tau, regardless of whether total tau or phosphorylated tau were used as primary outcomes. Power increased when eligibility criteria were broadened to allow for enrollment of subjects with either low amyloid beta or high phosphorylated tau. Conclusion: Specific biomarker inclusion criteria may impact statistical power in trials using total tau or phosphorylated tau as the primary outcome. In concert with other important considerations such as treatment target and population of clinical interest, these results may have implications to the integrity and efficiency of prodromal Alzheimer’s disease trial designs.


2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Yui Nakayama ◽  
Satoru Morimoto ◽  
Misao Yoneda ◽  
Shigeki Kuzuhara ◽  
Yasumasa Kokubo

Objective. Amyotrophic lateral sclerosis/parkinsonism-dementia complex is classified as one of the tauopathies. Methods. The total tau, phosphorylated tau, and amyloid β42 levels were assayed in cerebrospinal fluid from patients with Kii amyotrophic lateral sclerosis/parkinsonism-dementia complex (), Alzheimer’s disease (), Parkinson’s disease (), amyotrophic lateral sclerosis (), and controls () using specific enzyme-linked immunosorbent assay methods. Results. Total tau and phosphorylated tau did not increase and amyloid β42 was relatively reduced in Kii amyotrophic lateral sclerosis/parkinsonism-dementia complex. Relatively reduced amyloid β42 might discriminate Kii amyotrophic lateral sclerosis/parkinsonism-dementia complex from amyotrophic lateral sclerosis and Parkinson’s disease, and the ratios of phosphorylated-tau to amyloid β42 could discriminate Kii amyotrophic lateral sclerosis/parkinsonism-dementia complex from Alzheimer’s disease. Conclusions. Cerebrospinal fluid analysis may be useful to differentiate amyotrophic lateral sclerosis/parkinsonism-dementia complex from Alzheimer’s disease, amyotrophic lateral sclerosis, and Parkinson’s disease.


2021 ◽  
Vol 84 (6) ◽  
pp. 472-480
Author(s):  
Yulin Luo ◽  
Li Tan ◽  
Joseph Therriault ◽  
Hua Zhang ◽  
Ying Gao ◽  
...  

<b><i>Background:</i></b> Apolipoprotein E (<i>APOE</i>) ε4 is highly associated with mild cognitive impairment (MCI). However, the specific influence of <i>APOE</i> ε4 status on tau pathology and cognitive decline in early MCI (EMCI) and late MCI (LMCI) is poorly understood. Our goal was to evaluate the association of <i>APOE</i> ε4 with cerebrospinal fluid (CSF) tau levels and cognition in EMCI and LMCI patients in the Alzheimer’s Disease Neuroimaging Initiative database, and whether this association was mediated by amyloid-β (Aβ). <b><i>Methods:</i></b> Participants were 269 cognitively normal (CN), 262 EMCI, and 344 LMCI patients. They underwent CSF Aβ42 and tau detection, <i>APOE</i> ε4 genotyping, Mini-Mental State Examination, (MMSE), and Alzheimer’s disease assessment scale (ADAS)-cog assessments. Linear regressions were used to examine the relation of <i>APOE</i> ε4 and CSF tau levels and cognitive scores in persons with and without Aβ deposition (Aβ+ and Aβ−). <b><i>Results:</i></b> The prevalence of <i>APOE</i> ε4 is higher in EMCI and LMCI than in CN (<i>p</i> &#x3c; 0.001 for both), and in LMCI than in EMCI (<i>p</i> = 0.001). <i>APOE</i> ε4 allele was significantly higher in Aβ+ subjects than in Aβ− subjects (<i>p</i> &#x3c; 0.001). Subjects who had a lower CSF Aβ42 level and were <i>APOE</i> ε4-positive experienced higher levels of CSF tau and cognitive scores in EMCI and/or LMCI. <b><i>Conclusions:</i></b> An <i>APOE</i> ε4 allele is associated with increased CSF tau and worse cognition in both EMCI and LMCI, and this association may be mediated by Aβ. We conclude that <i>APOE</i> ε4 may be an important mediator of tau pathology and cognition in the early stages of AD.


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