scholarly journals Continuous gait monitoring discriminates community‐dwelling mild Alzheimer's disease from cognitively normal controls

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Vijay R. Varma ◽  
Rahul Ghosal ◽  
Inbar Hillel ◽  
Dmitri Volfson ◽  
Jordan Weiss ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Community Dwelling ◽  
Cognitively Normal ◽  
Gait Monitoring ◽  
Normal Controls

scholarly journals The Correlations Between Plasma Fibrinogen With Amyloid-Beta and Tau Levels in Patients With Alzheimer’s Disease

2021 ◽  
Vol 14 ◽  
Author(s):  
Dong-Yu Fan ◽  
Hao-Lun Sun ◽  
Pu-Yang Sun ◽  
Jie-Ming Jian ◽  
Wei-Wei Li ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Plasma Fibrinogen ◽  
Cognitively Normal ◽  
Amyloid Aβ ◽  
And Gender ◽  
T Tau ◽  
The Relationship ◽  
Phosphorylated Tau 181 ◽  
Normal Controls

Recent studies show that fibrinogen plays a role in the pathogenesis of Alzheimer’s disease (AD), which may be crucial to neurovascular damage and cognitive impairment. However, there are few clinical studies on the relationship between fibrinogen and AD. 59 11C-PiB-PET diagnosed AD patients and 76 age- and gender-matched cognitively normal controls were included to analyze the correlation between plasma β-amyloid (Aβ) and tau levels with fibrinogen levels. 35 AD patients and 76 controls with cerebrospinal fluid (CSF) samples were included to further analyze the correlation between CSF Aβ and tau levels with fibrinogen levels. In AD patients, plasma fibrinogen levels were positively correlated with plasma Aβ40 and Aβ42 levels, and negatively correlated with CSF Aβ42 levels. Besides, fibrinogen levels were positively correlated with CSF total tau (t-tau), and phosphorylated tau-181 (p-tau) levels and positively correlated with the indicators of Aβ deposition in the brain, such as t-tau/Aβ42, p-tau/Aβ42 levels. In normal people, fibrinogen levels lack correlation with Aβ and tau levels in plasma and CSF. This study suggests that plasma fibrinogen levels are positively correlated with Aβ levels in the plasma and brain in AD patients. Fibrinogen may be involved in the pathogenesis of AD.

Blood circulating miRNAs as biomarkers of Alzheimer’s disease: a systematic review and meta-analysis

2019 ◽  
Vol 13 (12) ◽  
pp. 1045-1054
Author(s):  
Ya-Heng Zhang ◽  
Shu-Feng Bai ◽  
Jun-Qiang Yan
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Odds Ratio ◽  
Diagnostic Performance ◽  
Meta Analysis ◽  
Diagnostic Odds Ratio ◽  
Circulating Mirnas ◽  
Cognitively Normal ◽  
Specificity And Sensitivity ◽  
Normal Controls

Aim: It is already known that miRNAs can be differentially expressed in Alzheimer’s disease (AD). We aimed to evaluate the performance of miRNAs from blood as potential biomarkers for AD. Materials & methods: MEDLINE, PubMed and Embase were searched for studies about peripheral blood miRNAs that could discriminate patients with AD from cognitively normal controls. The data regarding the specificity and sensitivity were extracted. STATA 14.0 was used to analyze the data. Results: Ten studies containing 770 AD and 664 normal controls. The analysis showed that miRNAs presented excellent diagnostic performance and the overall sensitivity was 0.80 (95% CI: 0.75–0.83), specificity was 0.83 (95% CI: 0.78–0.87) and diagnostic odds ratio was 14 (95% CI: 11–19). Subgroup analysis suggested that the Caucasian group and blood group showed a better performance in AD diagnosis and the diagnostic odds ratio was 42 and 34, respectively. Conclusion: This meta-analysis showed that miRNAs may be a promising biomarkers for AD.

scholarly journals 18F-flortaucipir PET to autopsy comparisons in Alzheimer’s disease and other neurodegenerative diseases

Brain ◽  
2020 ◽  
Vol 143 (11) ◽  
pp. 3477-3494 ◽  
Author(s):  
David N Soleimani-Meigooni ◽  
Leonardo Iaccarino ◽  
Renaud La Joie ◽  
Suzanne Baker ◽  
Viktoriya Bourakova ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Progressive Supranuclear Palsy ◽  
Frontotemporal Lobar Degeneration ◽  
Neurofibrillary Tangle ◽  
Corticobasal Degeneration ◽  
Braak Stage ◽  
Tau Pathology ◽  
Cognitively Normal ◽  
Normal Controls

Abstract Few studies have evaluated the relationship between in vivo18F-flortaucipir PET and post-mortem pathology. We sought to compare antemortem 18F-flortaucipir PET to neuropathology in a consecutive series of patients with a broad spectrum of neurodegenerative conditions. Twenty patients were included [mean age at PET 61 years (range 34–76); eight female; median PET-to-autopsy interval of 30 months (range 4–59 months)]. Eight patients had primary Alzheimer’s disease pathology, nine had non-Alzheimer tauopathies (progressive supranuclear palsy, corticobasal degeneration, argyrophilic grain disease, and frontotemporal lobar degeneration with MAPT mutations), and three had non-tau frontotemporal lobar degeneration. Using an inferior cerebellar grey matter reference, 80–100-min 18F-flortaucipir PET standardized uptake value ratio (SUVR) images were created. Mean SUVRs were calculated for progressive supranuclear palsy, corticobasal degeneration, and neurofibrillary tangle Braak stage regions of interest, and these values were compared to SUVRs derived from young, non-autopsy, cognitively normal controls used as a standard for tau negativity. W-score maps were generated to highlight areas of increased tracer retention compared to cognitively normal controls, adjusting for age as a covariate. Autopsies were performed blinded to PET results. There was excellent correspondence between areas of 18F-flortaucipir retention, on both SUVR images and W-score maps, and neurofibrillary tangle distribution in patients with primary Alzheimer’s disease neuropathology. Patients with non-Alzheimer tauopathies and non-tau frontotemporal lobar degeneration showed a range of tracer retention that was less than Alzheimer’s disease, though higher than age-matched, cognitively normal controls. Overall, binding across both tau-positive and tau-negative non-Alzheimer disorders did not reliably correspond with post-mortem tau pathology. 18F-flortaucipir SUVRs in subcortical regions were higher in autopsy-confirmed progressive supranuclear palsy and corticobasal degeneration than in controls, but were similar to values measured in Alzheimer’s disease and tau-negative neurodegenerative pathologies. Quantification of 18F-flortaucipir SUVR images at Braak stage regions of interest reliably detected advanced Alzheimer’s (Braak VI) pathology. However, patients with earlier Braak stages (Braak I–IV) did not show elevated tracer uptake in these regions compared to young, tau-negative controls. In summary, PET-to-autopsy comparisons confirm that 18F-flortaucipir PET is a reliable biomarker of advanced Braak tau pathology in Alzheimer’s disease. The tracer cannot reliably differentiate non-Alzheimer tauopathies and may not detect early Braak stages of neurofibrillary tangle pathology.

scholarly journals An Updated Mendelian Randomization Analysis of the Association Between Serum Calcium Levels and the Risk of Alzheimer’s Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuchen Shi ◽  
Ruifei Liu ◽  
Ying Guo ◽  
Qiwei Li ◽  
Haichun Zhou ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Serum Calcium ◽  
Large Scale ◽  
Mendelian Randomization ◽  
Causal Association ◽  
Cognitively Normal ◽  
Gwas Dataset ◽  
Weighted Median ◽  
Normal Controls

It has been a long time that the relationship between serum calcium levels and Alzheimer’s disease (AD) remains unclear. Until recently, observational studies have evaluated the association between serum calcium levels and the risk of AD, however, reported inconsistent findings. Meanwhile, a Mendelian randomization (MR) study had been conducted to test the causal association between serum calcium levels and AD risk, however, only selected 6 serum calcium SNPs as the instrumental variables. Hence, these findings should be further verified using additional more genetic variants and large-scale genome-wide association study (GWAS) dataset to increase the statistical power. Here, we conduct an updated MR analysis of the causal association between serum calcium levels and the risk of AD using a two-stage design. In discovery stage, we conducted a MR analysis using 14 SNPs from serum calcium GWAS dataset (N = 61,079), and AD GWAS dataset (N = 63,926, 21,982 cases, 41,944 cognitively normal controls). All four MR methods including IVW, weighted median, MR-Egger, and MR-PRESSO showed a reduced trend of AD risk with the increased serum calcium levels. In the replication stage, we performed a MR analysis using 166 SNPs from serum calcium GWAS dataset (N = 305,349), and AD GWAS dataset (N = 63,926, 21,982 cases, 41,944 cognitively normal controls). Only the weighted median indicated that genetically increased serum calcium level was associated with the reduced risk of AD. Hence, additional studies are required to investigate these findings.

APOE ɛ4-TOMM40L Haplotype Increases the Risk of Mild Cognitive Impairment Conversion to Alzheimer’s Disease

2020 ◽  
Vol 78 (2) ◽  
pp. 587-601
Author(s):  
Remy Cardoso ◽  
Carolina Lemos ◽  
Bárbara Oliveiros ◽  
Maria Rosário Almeida ◽  
Inês Baldeiras ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Apoe Genotype ◽  
Csf Biomarkers ◽  
Cognitively Normal ◽  
Conversion Time ◽  
E4 Allele ◽  
Normal Controls

Background: Mild cognitive impairment (MCI) has been considered as a pre-dementia stage, although the factors leading to Alzheimer’s disease (AD) conversion remain controversial. Objective: Evaluate whether TOMM40 poly-T (TOMM40′ 523) polymorphism is associated with the risk and conversion time from MCI to AD and secondly with AD cerebrospinal fluid (CSF) biomarkers, disentangling the APOE genotype. Methods: 147 AD patients, 102 MCI patients, and 105 cognitively normal controls were genotyped for poly-T polymorphism. MCI patients were subdivided into two groups, the group of patients that converted to AD (MCI-AD) and the group of those that remained stable (MCI-S). Results: TOMM40′ 523 L allele was significantly more frequent in the MCI-AD group and having at least one L allele significantly increased the risk of conversion from MCI to AD (OR = 8.346, p < 0.001, 95% CI: 2.830 to 24.617). However, when adjusted for the presence of APOE ɛ4 allele, both the L allele and ɛ4 allele lost significance in the model (p > 0.05). We then analyzed the APOE ɛ4-TOMM40′ 523 L haplotype and observed that patients carrying this haplotype had significantly higher risk (OR = 5.83; 95% CI = 2.30–14.83) and mean lower times of conversion to AD (p = 0.003). This haplotype was also significantly associated with a biomarker profile compatible with AD (p = 0.007). Conclusion: This study shows that the APOE ɛ4-TOMM40′ 523 L haplotype is associated with a higher risk and shorter times of conversion from MCI to AD, possibly driven by CSF biomarkers and mitochondrial dysfunction.

The Correlation of Tau Levels with Blood Monocyte Count in Patients with Alzheimer’s Disease

2021 ◽  
pp. 1-8
Author(s):  
Hao-Lun Sun ◽  
Fa-Ying Zhou ◽  
Dong-Wan Chen ◽  
Cheng-Rong Tan ◽  
Gui-Hua Zeng ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tau Protein ◽  
Amyloid Β ◽  
Blood Monocyte ◽  
Monocyte Count ◽  
Cognitively Normal ◽  
T Tau ◽  
Normal Controls ◽  
Age And Sex

Background: Recent studies have shown that monocytes can phagocytize the tau protein, which may ameliorate tau-type pathology in Alzheimer’s disease (AD). However, there are few clinical studies on the relationship between monocytes and tau-type pathology in AD patients. Objective: We aimed to explore changes in peripheral monocytes and their association with tau protein in AD patients. Methods: A total of 127 clinically diagnosed AD patients and 100 age- and sex-matched cognitively normal controls were recruited for analysis of the correlation of plasma tau levels with the blood monocyte count. Cerebrospinal fluid (CSF) samples from 46 AD patients and 88 controls were further collected to analyze the correlation of CSF tau and amyloid-β (Aβ) levels with the blood monocyte count. 105 clinically diagnosed mild cognitive impairment (MCI) patients and 149 age- and sex-matched cognitively normal controls were recruited from another cohort for verification. Results: Compared to normal controls, AD patients showed a significant reduction in the blood monocyte count. In addition, the monocyte count of AD patients was negatively correlated with CSF t-tau and p-tau levels but not with plasma tau levels. In normal people, monocyte count lack correlation with tau levels both in plasma and CSF. Monocyte count were not correlated with CSF Aβ levels in either group but were negatively correlated with CSF tau/Aβ 42 levels in the AD group. We had further verified the correlations of monocyte count with CSF tau levels in another cohort. Conclusion: This study suggests that monocytes may play an important role in the clearance of tau protein in the brain.

scholarly journals Genome-Wide DNA Methylation Differences Between Late-Onset Alzheimer's Disease and Cognitively Normal Controls in Human Frontal Cortex

2012 ◽  
Vol 29 (3) ◽  
pp. 571-588 ◽  
Author(s):  
Kelly M. Bakulski ◽  
Dana C. Dolinoy ◽  
Maureen A. Sartor ◽  
Henry L. Paulson ◽  
John R. Konen ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Dna Methylation ◽  
Frontal Cortex ◽  
Late Onset ◽  
Cognitively Normal ◽  
Genome Wide ◽  
Human Frontal Cortex ◽  
Normal Controls

scholarly journals 5-Hydroxymethylcytosine Signatures in Circulating Cell-Free DNA as Diagnostic Biomarkers for Late-Onset Alzheimer’s Disease

2021 ◽  
Author(s):  
Lei Chen ◽  
Shunliang Xu ◽  
Qianqian Shen ◽  
Hongzhuan Yu ◽  
Shengjie Pei ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Late Onset ◽  
Cell Free Dna ◽  
Cognitively Normal ◽  
Free Dna ◽  
Genome Wide ◽  
Significant Difference ◽  
Normal Controls ◽  
Circulating Cell Free Dna

Abstract Background: 5-Hydroxymethylcytosine (5hmC) is an epigenetic DNA modification that is highly abundant in nervous system. It has been reported that 5hmC is significant associated with Alzheimer’s disease (AD). Changes in 5hmC signatures can be detected in circulating cell-free DNA (cfDNA), which has shown potential as a non-invasive liquid biopsy material. However, there is no research about genome-wide profiling of 5hmC in cfDNA and its potential for the diagnosis of AD to date. Methods: We carried out a case-control study and used a highly sensitive and selective high-throughput sequencing of chemical labels to detect the genome-wide profiles of 5hmC in human cfDNA and identified differentially hydroxymethylated regions (DhMRs) in AD patients and the control. Results: We detected a significant difference of 5hmC enrichment in gene bodies which were linked to multiple AD pathogenesis-associated signaling pathways in AD patients compared with cognitively normal controls. AD patients can be well distinguished from cognitively normal controls by differentially hydroxymethylated regions (DhMRs) in cfDNA. Specially, we found 7 distinct genes (RABEP1, CPNE4, DNAJC15, REEP3, ROR1, CAMK1D, and RBFOX1) had prediction diagnostic potential based on their significant correlations with MMSE and MoCA scores. Conclusions: The present results suggest that 5hmC markers derived from plasma cfDNA can be served as an effective, minimally invasive biomarkers for clinical auxiliary diagnosis of late-onset AD. Trial registration: Chinese Clinical Trial Registry, ChiCTR2100042537, registered 13 January 2021-retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=120582.

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