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 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.

scholarly journals Amyloid-beta uptake by blood monocytes is reduced with ageing and Alzheimer’s disease

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Si-Han Chen ◽  
Ding-Yuan Tian ◽  
Ying-Ying Shen ◽  
Yuan Cheng ◽  
Dong-Yu Fan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Β ◽  
Blood Levels ◽  
Amyloid Β Protein ◽  
Blood Monocytes ◽  
Cognitively Normal ◽  
Β Protein ◽  
Toll Like Receptor 2 ◽  
Age And Sex

AbstractDeficits in the clearance of amyloid β-protein (Aβ) play a pivotal role in the pathogenesis of sporadic Alzheimer’s disease (AD). The roles of blood monocytes in the development of AD remain unclear. In this study, we sought to investigate the alterations in the Aβ phagocytosis function of peripheral monocytes during ageing and in AD patients. A total of 104 cognitively normal participants aged 22–89 years, 24 AD patients, 25 age- and sex-matched cognitively normal (CN) subjects, 15 Parkinson’s disease patients (PD), and 15 age- and sex-matched CN subjects were recruited. The Aβ uptake by blood monocytes was measured and its alteration during ageing and in AD patients were investigated. Aβ1-42 uptake by monocytes decreased during ageing and further decreased in AD but not in PD patients. Aβ1-42 uptake by monocytes was associated with Aβ1-42 levels in the blood. Among the Aβ uptake-related receptors and enzymes, the expression of Toll-like receptor 2 (TLR2) was reduced in monocytes from AD patients. Our findings suggest that monocytes regulate the blood levels of Aβ and might be involved in the development of AD. The recovery of the Aβ uptake function by blood monocytes represents a potential therapeutic strategy for AD.

scholarly journals Amyloid-beta Uptake by Peripheral Blood Monocytes is Reduced by Ageing and Alzheimer’s Disease

2020 ◽  
Author(s):  
Si-Han Chen ◽  
Ding-Yuan Tian ◽  
Ying-Ying Shen ◽  
Yuan Cheng ◽  
Dong-Yu Fan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Β ◽  
Blood Levels ◽  
Amyloid Β Protein ◽  
Blood Monocytes ◽  
Cognitively Normal ◽  
Β Protein ◽  
Toll Like Receptor 2 ◽  
Age And Sex

Abstract BackgroundDeficits in the clearance of amyloid β-protein (Aβ) play a pivotal role in the pathogenesis of sporadic Alzheimer’s disease (AD). The roles of blood monocytes, the counterpartsof microglia in the periphery, in the development of AD remain unclear. In this study, we sought to investigate the alterations in the Aβ phagocytosis function of peripheral monocytes during ageing and in AD patients. Methods:A total of104 cognitively normal participants aged 22 to 89 years old, 22 AD patients, 22 age- and sex-matched cognitively normal (CN) subjects, 15 Parkinson’s disease patients (PD) and 15 age- and sex-matched CN subjects were recruited. The Aβ uptake by blood monocytes were measured and its alteration during ageing and in AD were investigated. ResultsAβ1-42 uptake by monocytes was associated with Aβ1-42 levels in the blood. Aβ1-42 uptake by monocytes decreased during ageing, and further decreased in AD but not in PD patients. Among the Aβ uptake-related receptors and enzymes, the expression of Toll‑like receptor 2 (TLR2) was reduced in monocytes from AD patients.ConclusionOur findings suggest that monocytes regulate the blood levels of Aβ and might be involved in the development of AD. The recovery of the Aβ clearance function by blood monocytes represents a potential therapeutic strategy for AD.

scholarly journals Serum Amyloid Biomarkers, Tau Protein and YKL-40 Utility in Detection, Differential Diagnosing, and Monitoring of Dementia

2021 ◽  
Vol 12 ◽  
Author(s):  
Karolina Wilczyńska ◽  
Mateusz Maciejczyk ◽  
Anna Zalewska ◽  
Napoleon Waszkiewicz
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tau Protein ◽  
Inflammatory Diseases ◽  
Normal Subjects ◽  
Diagnostic Utility ◽  
Cognitively Normal ◽  
Ad Alzheimer’S Disease ◽  
Cognitively Normal Subjects ◽  
T Tau

Introduction: The diagnosis and treatment of dementia is one of the greatest challenges in contemporary health care. The widespread use of dementia biomarkers would improve the quality of life of patients and reduce the economic costs of the disease. The aim of the study was to evaluate the usefulness of proteins related to the Alzheimer's disease pathogenesis—amyloid beta isoform (Aβ) and total tau protein (t-tau), as well as the quite recently discovered marker YKL-40 in the most common types of dementia.Methods: 60 dementia (AD—Alzheimer's disease, VaD—vascular dementia, MxD—mixed dementia) and 20 cognitively normal subjects over 60 years old were examined. Subjects with dementia of etiology different than AD or VaD and with neoplastic or chronic inflammatory diseases were excluded. Concentrations of Aβ40, Aβ42, t-tau, and YKL-40 were measured in serum using ELISA kits on admission and after 4 weeks of inpatient treatment. ANOVA and Tukey's test or Dunn's test were used to perform comparison tests between groups. Correlations were measured using Pearson's coefficient. Biomarker diagnostic utility was assessed with ROC analysis.Results: YKL-40 differentiates between cognitively normal and mild dementia patients with 85% sensitivity and specificity and t-tau with 72% sensitivity and 70% specificity. YKL-40 and t-tau concentrations correlate with each other and with the severity of clinically observed cognitive decline.Conclusions: YKL-40 is a sensitive and specific biomarker of early dementia and, to a lesser extent, of dementia progression, however, many comorbidities may influence its levels. In such conditions, less specific but still reliable t-tau may serve as an alternative marker. Obtained results did not confirm the diagnostic utility of amyloid biomarkers.

scholarly journals Amyloid-beta uptake by peripheral blood monocytes is reduced by ageing and Alzheimer’s disease

2020 ◽  
Author(s):  
Si-Han Chen ◽  
Ding-Yuan Tian ◽  
Ying-Ying Shen ◽  
Yuan Cheng Bachelor ◽  
Dong-Yu Fan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Β ◽  
Blood Levels ◽  
Amyloid Β Protein ◽  
Blood Monocytes ◽  
Cognitively Normal ◽  
Β Protein ◽  
Toll Like Receptor 2 ◽  
Age And Sex

Abstract Background: Deficits in the clearance of amyloid β-protein (Aβ) play a pivotal role in the pathogenesis of sporadic Alzheimer’s disease (AD). The roles of blood monocytes, the counterparts of microglia in the periphery, in the development of AD remain unclear. In this study, we sought to investigate the alterations in the Aβ phagocytosis function of peripheral monocytes during ageing and in AD patients. Methods: A total of 104 cognitively normal participants aged 22 to 89 years old, 22 AD patients, 22 age- and sex-matched cognitively normal (CN) subjects, 15 Parkinson’s disease patients (PD) and 15 age- and sex-matched CN subjects were recruited. The Aβ uptake by blood monocytes were measured and its alteration during ageing and in AD were investigated. Results: Aβ1−42 uptake by monocytes was associated with Aβ1−42 levels in the blood. Aβ1−42 uptake by monocytes decreased during ageing, and further decreased in AD but not in PD patients. Among the Aβ uptake-related receptors and enzymes, the expression of Toll‑like receptor 2 (TLR2) was reduced in monocytes from AD patients. Conclusions: Our findings suggest that monocytes regulate the blood levels of Aβ and might be involved in the development of AD. The recovery of the Aβ clearance function by blood monocytes represents a potential therapeutic strategy for AD.

Plasma Levels of Amyloid-β Peptides and Tau Protein in Mexican Patients with Alzheimer’s Disease

2021 ◽  
pp. 1-11
Author(s):  
Tzayaka Castillo-Mendieta ◽  
Yoaly Arana-Lechuga ◽  
Victoria Campos-Peña ◽  
Ana Luisa Sosa ◽  
Sandra Orozco-Suarez ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tau Protein ◽  
Amyloid Β ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Plasma Biomarkers ◽  
Control Subjects ◽  
And Control ◽  
T Tau

Background: Alzheimer’s disease (AD) causes memory deficit and alterations in other cognitive functions, mainly in adults over 60 years of age. As the diagnosis confirmation is performed by a postmortem neuropathological examination of the brain, this disease can be confused with other types of dementia at early stages. About 860,000 Mexicans are affected by dementia, most of them with insufficient access to adequate comprehensive health care services. Plasma biomarkers could be a rapid option for early diagnosis of the disease. Objective: This study aimed to analyze some plasma biomarkers (amyloid-β, tau, and lipids) in Mexican AD patients and control subjects with no associated neurodegenerative diseases. Methods: Plasma amyloid-β peptides (Aβ 40 and Aβ 42), total and phosphorylated tau protein (T-tau and P-tau), and cholesterol and triglyceride levels were quantified enzyme-linked immunosorbent assay in AD patients and control subjects. Results: In Mexican AD patients, we found significantly lower levels of Aβ 42 (p <  0.05) compared to the control group. In contrast, significantly higher levels of P-tau (p <  0.05) and triglycerides (p <  0.05) were observed in AD patients compared to controls. Furthermore, a significant correlation was found between the severity of dementia and plasma P-tau levels, Aβ 42/Aβ 40 and P-tau/T-tau ratios, and triglycerides concentrations. This correlation increased gradually with cognitive decline. Conclusion: The detection of these plasma biomarkers is an initial step in searching for a timely, less invasive, and cost-efficient diagnosis in Mexicans.

scholarly journals Peripheral Markers of Vascular Endothelial Dysfunction Show Independent but Additive Relationships with Brain-Based Biomarkers in Association with Functional Impairment in Alzheimer’s Disease

2021 ◽  
pp. 1-13
Author(s):  
Jonathan D. Drake ◽  
Alison B. Chambers ◽  
Brian R. Ott ◽  
Lori A. Daiello ◽  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cell Adhesion ◽  
Adhesion Molecule ◽  
Functional Impairment ◽  
Amyloid Β ◽  
Intercellular Adhesion Molecule ◽  
Csf Biomarkers ◽  
Linear Regression Models ◽  
Cognitively Normal

Background: Cerebrovascular dysfunction confers risk for functional decline in Alzheimer’s disease (AD), yet the clinical interplay of these two pathogenic processes is not well understood. Objective: We utilized Alzheimer’s Disease Neuroimaging Initiative (ADNI) data to examine associations between peripherally derived soluble cell adhesion molecules (CAMs) and clinical diagnostic indicators of AD. Methods: Using generalized linear regression models, we examined cross-sectional relationships of soluble plasma vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-Selectin to baseline diagnosis and functional impairment (clinical dementia rating sum-of-boxes, CDR-SB) in the ADNI cohort (n = 112 AD, n = 396 mild cognitive impairment (MCI), n = 58 cognitively normal). We further analyzed associations of these biomarkers with brain-based AD biomarkers in a subset with available cerebrospinal fluid (CSF) data (n = 351). p-values derived from main effects and interaction terms from the linear regressions were used to assess the relationship between independent and dependent variables for significance (significance level was set at 0.05 a priori for all analysis). Results: Higher mean VCAM-1 (p = 0.0026) and ICAM-1 (p = 0.0189) levels were found in AD versus MCI groups; however, not in MCI versus cognitively normal groups. Only VCAM-1 was linked with CDR-SB scores (p = 0.0157), and APOE ɛ4 genotype modified this effect. We observed independent, additive associations when VCAM-1 and CSF amyloid-β (Aβ 42), total tau, phosphorylated tau (P-tau), or P-tau/Aβ 42 (all <  p = 0.01) were combined in a CDR-SB model; ICAM-1 showed a similar pattern, but to a lesser extent. Conclusion: Our findings indicate independent associations of plasma-based vascular biomarkers and CSF biomarkers with AD-related clinical impairment.

Influence of White Matter Hyperintensities on Baseline and Longitudinal Amyloid-β in Cognitively Normal Individuals

2021 ◽  
pp. 1-11
Author(s):  
Fennie Choy Chin Wong ◽  
Seyed Ehsan Saffari ◽  
Chathuri Yatawara ◽  
Kok Pin Ng ◽  
Nagaendran Kandiah ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Executive Function ◽  
White Matter ◽  
White Matter Hyperintensities ◽  
Small Vessel Disease ◽  
Amyloid Β ◽  
Intracranial Volume ◽  
Linear Regression Models ◽  
Cognitively Normal

Background: The associations between small vessel disease (SVD) and cerebrospinal amyloid-β1-42 (Aβ1-42) pathology have not been well-elucidated. Objective: Baseline (BL) white matter hyperintensities (WMH) were examined for associations with month-24 (M24) and longitudinal Aβ1-42 change in cognitively normal (CN) subjects. The interaction of WMH and Aβ1-42 on memory and executive function were also examined. Methods: This study included 72 subjects from the Alzheimer’s Disease Neuroimaging Initiative. Multivariable linear regression models evaluated associations between baseline WMH/intracranial volume ratio, M24 and change in Aβ1-42 over two years. Linear mixed effects models evaluated interactions between BL WMH/ICV and Aβ1-42 on memory and executive function. Results: Mean age of the subjects (Nmales = 36) = 73.80 years, SD = 6.73; mean education years = 17.1, SD = 2.4. BL WMH was significantly associated with M24 Aβ1-42 (p = 0.008) and two-year change in Aβ1-42 (p = 0.006). Interaction between higher WMH and lower Aβ1-42 at baseline was significantly associated with worse memory at baseline and M24 (p = 0.003). Conclusion: BL WMH was associated with M24 and longitudinal Aβ1-42 change in CN. The interaction between higher WMH and lower Aβ1-42 was associated with poorer memory. Since SVD is associated with longitudinal Aβ1-42 pathology, and the interaction of both factors is linked to poorer cognitive outcomes, the mitigation of SVD may be correlated with reduced amyloid pathology and milder cognitive deterioration in Alzheimer’s disease.

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