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Alzheimer's Research & Therapy Jan 2019Alzheimer's disease (AD) pathology begins several years before the clinical onset. The long preclinical phase is composed of three stages according to the 2011National... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Alzheimer's disease (AD) pathology begins several years before the clinical onset. The long preclinical phase is composed of three stages according to the 2011National Institute on Aging and Alzheimer's Association (NIA-AA) criteria, followed by mild cognitive impairment (MCI), a featured clinical entity defined as "due to AD", or "prodromal AD", when pathophysiological biomarkers (i.e., cerebrospinal fluid or positron emission tomography with amyloid tracer) are positive. In the clinical setting, there is a clear need to detect the earliest symptoms not yet fulfilling MCI criteria, in order to proceed to biomarker assessment for diagnostic definition, thus offering treatment with disease-modifying drugs to patients as early as possible. According to the available evidence, we thus estimated the prevalence and risk of progression at each preclinical AD stage, with special interest in Stage 3.
METHODS
Cross-sectional and longitudinal studies published from April 2008 to May 2018 were obtained through MEDLINE-PubMed, screened, and systematically reviewed by four independent reviewers. Data from included studies were meta-analyzed using random-effects models. Heterogeneity was assessed by I statistics.
RESULTS
Estimated overall prevalence of preclinical AD was 22% (95% CI = 18-26%). Rate of biomarker positivity overlapped in cognitively normal individuals and people with subjective cognitive decline. The risk of progression increases across preclinical AD stages, with individuals classified as NIA-AA Stage 3 showing the highest risk (73%, 95% CI = 40-92%) compared to those in Stage 2 (38%, 95% CI = 21-59%) and Stage 1 (20%, 95% CI = 10-34%).
CONCLUSION
Available data consistently show that risk of progression increases across the preclinical AD stages, where Stage 3 shows a risk of progression comparable to MCI due to AD. Accordingly, an effort should be made to also operationalize the diagnostic work-up in subjects with subtle cognitive deficits not yet fulfilling MCI criteria. The possibility to define, in the clinical routine, a patient as "pre-MCI due to AD" could offer these subjects the opportunity to use disease-modifying drugs at best.
Topics: Alzheimer Disease; Cross-Sectional Studies; Disease Progression; Humans; Longitudinal Studies; Prevalence; Prodromal Symptoms; Risk Factors
PubMed: 30646955
DOI: 10.1186/s13195-018-0459-7 -
Biomolecules Feb 2022Alzheimer's disease (AD) incidence is increasing worldwide at an alarming rate. Considering this increase, prevention efforts, stemming from scientific research, health... (Review)
Review
Alzheimer's disease (AD) incidence is increasing worldwide at an alarming rate. Considering this increase, prevention efforts, stemming from scientific research, health education, and public policies, are critical. Clinical studies evidenced that healthy lifestyles along with natural multitarget and disease-modifying agents have a preventative impact on AD or mitigate symptoms in diagnosed patients. The pathological alterations of AD start 30 years before symptoms, and it is essential to develop the capacity to detect those changes. In this regard, molecular biomarkers that detect early pathological manifestations are helpful. Based on markers data, early preventive interventions could reduce more than 40% of AD cases. Protective actions include exercise, shown to induce neurogenesis, cognitive stimulation, intellectual-social activity, and nutrition among others. Mediterranean diet, preprobiotics, and nutraceuticals containing bioactive molecules with antioxidant and anti-inflammatory properties are relevant. Antiprotein aggregation molecules whose mechanisms were described are important. Anti-inflammatory agents with anti-aggregation properties that help to control cognitive impairment, include quercetin, biocurcumin, rosemarinic acid, and Andean . Anthocyanidins, e.g., delphinidin, malvidin, and natural flavonoids, are also included. Quercetin and hydroxy-tyrosol are antiaging molecules and could have anti-AD properties. We emphasize the relevance of nutraceuticals as a main actor in the prevention and/or control of dementia and particularly AD.
Topics: Alzheimer Disease; Antioxidants; Cognitive Dysfunction; Diet, Mediterranean; Dietary Supplements; Humans
PubMed: 35204750
DOI: 10.3390/biom12020249 -
Current Opinion in Lipidology Jun 2019We review current knowledge regarding HDL and Alzheimer's disease, focusing on HDL's vasoprotective functions and potential as a biomarker and therapeutic target for the... (Review)
Review
PURPOSE OF REVIEW
We review current knowledge regarding HDL and Alzheimer's disease, focusing on HDL's vasoprotective functions and potential as a biomarker and therapeutic target for the vascular contributions of Alzheimer's disease.
RECENT FINDINGS
Many epidemiological studies have observed that circulating HDL levels associate with decreased Alzheimer's disease risk. However, it is now understood that the functions of HDL may be more informative than levels of HDL cholesterol (HDL-C). Animal model studies demonstrate that HDL protects against memory deficits, neuroinflammation, and cerebral amyloid angiopathy (CAA). In-vitro studies using state-of-the-art 3D models of the human blood-brain barrier (BBB) confirm that HDL reduces vascular Aβ accumulation and attenuates Aβ-induced endothelial inflammation. Although HDL-based therapeutics have not been tested in clinical trials for Alzheimer's disease , several HDL formulations are in advanced phase clinical trials for coronary artery disease and atherosclerosis and could be leveraged toward Alzheimer's disease .
SUMMARY
Evidence from human studies, animal models, and bioengineered arteries supports the hypothesis that HDL protects against cerebrovascular dysfunction in Alzheimer's disease. Assays of HDL functions relevant to Alzheimer's disease may be desirable biomarkers of cerebrovascular health. HDL-based therapeutics may also be of interest for Alzheimer's disease, using stand-alone or combination therapy approaches.
Topics: Alzheimer Disease; Animals; Comorbidity; Humans; Lipoproteins, HDL; Vascular Resistance
PubMed: 30946049
DOI: 10.1097/MOL.0000000000000604 -
Zoological Research Nov 2023Alzheimer's disease (AD) is an age-related progressive neurodegenerative disorder that leads to cognitive impairment and memory loss. Emerging evidence suggests that... (Review)
Review
Alzheimer's disease (AD) is an age-related progressive neurodegenerative disorder that leads to cognitive impairment and memory loss. Emerging evidence suggests that autophagy plays an important role in the pathogenesis of AD through the regulation of amyloid-beta (Aβ) and tau metabolism, and that autophagy dysfunction exacerbates amyloidosis and tau pathology. Therefore, targeting autophagy may be an effective approach for the treatment of AD. Animal models are considered useful tools for investigating the pathogenic mechanisms and therapeutic strategies of diseases. This review aims to summarize the pathological alterations in autophagy in representative AD animal models and to present recent studies on newly discovered autophagy-stimulating interventions in animal AD models. Finally, the opportunities, difficulties, and future directions of autophagy targeting in AD therapy are discussed.
Topics: Animals; Alzheimer Disease; Amyloid beta-Peptides; Autophagy; Models, Animal
PubMed: 37963840
DOI: 10.24272/j.issn.2095-8137.2023.294 -
Journal of Alzheimer's Disease : JAD 2018Alzheimer's disease (AD) is a highly complex neurodegenerative disorder and the current treatment strategies are largely ineffective thereby leading to irreversible and... (Review)
Review
Alzheimer's disease (AD) is a highly complex neurodegenerative disorder and the current treatment strategies are largely ineffective thereby leading to irreversible and progressive cognitive decline in AD patients. AD continues to defy successful treatment despite significant advancements in the field of molecular medicine. Repeatedly, early promising preclinical and clinical results have catapulted into devastating setbacks leading to multi-billion dollar losses not only to the top pharmaceutical companies but also to the AD patients and their families. Thus, it is very timely to review the progress in the emerging fields of gene therapy and stem cell-based precision medicine. Here, we have made sincere efforts to feature the ongoing progress especially in the field of AD gene therapy and stem cell-based regenerative medicine. Further, we also provide highlights in elucidating the molecular mechanisms underlying AD pathogenesis and describe novel AD therapeutic targets and strategies for the new drug discovery. We hope that the quantum leap in the scientific advancements and improved funding will bolster novel concepts that will propel the momentum toward a trajectory leading to a robust AD patient-specific next generation precision medicine with improved cognitive function and excellent life quality.
Topics: Alzheimer Disease; Animals; Gene Editing; Genetic Therapy; Humans; Precision Medicine; Stem Cell Transplantation
PubMed: 30040732
DOI: 10.3233/JAD-180422 -
Alzheimer's Research & Therapy Aug 2022Patient stratification is the division of a patient population into distinct subgroups based on the presence or absence of particular disease characteristics. As patient... (Review)
Review
BACKGROUND
Patient stratification is the division of a patient population into distinct subgroups based on the presence or absence of particular disease characteristics. As patient stratification can be used to account for the underlying pathology of a disease, it can help physicians to tailor therapeutic interventions to individuals and optimize their care management and treatment regime. Alzheimer's disease, the most common form of dementia, is a heterogeneous disease and its management benefits from patient stratification in clinical trials, and the development of personalized care and treatment strategies for people living with the disease.
MAIN BODY
In this review, we discuss the importance of the stratification of people living with Alzheimer's disease, the challenges associated with early diagnosis and patient stratification, and the evolution of patient stratification once disease-modifying therapies become widely available.
CONCLUSION
Patient stratification plays an important role in drug development in clinical trials and may play an even larger role in clinical practice. A timely diagnosis and stratification of people living with Alzheimer's disease is paramount in determining people who are at risk of progressing from mild cognitive impairment to Alzheimer's dementia. There are key issues associated with stratifying patients which include the heterogeneity and complex neurobiology behind Alzheimer's disease, our inadequately prepared healthcare systems, and the cultural perceptions of Alzheimer's disease. Stratifying people living with Alzheimer's disease may be the key in establishing precision and personalized medicine in the field, optimizing disease prevention and pharmaceutical treatment to slow or stop cognitive decline, while minimizing adverse effects.
Topics: Alzheimer Disease; Cognitive Dysfunction; Humans
PubMed: 35964143
DOI: 10.1186/s13195-022-01055-y -
Journal of Alzheimer's Disease : JAD 2018Translational neuroscience integrates the knowledge derived by basic neuroscience with the development of new diagnostic and therapeutic tools that may be applied to... (Review)
Review
Translational neuroscience integrates the knowledge derived by basic neuroscience with the development of new diagnostic and therapeutic tools that may be applied to clinical practice in neurological diseases. This information can be used to improve clinical trial designs and outcomes that will accelerate drug development, and to discover novel biomarkers which can be efficiently employed to early recognize neurological disorders and provide information regarding the effects of drugs on the underlying disease biology. Alzheimer's disease (AD) and prion disease are two classes of neurodegenerative disorders characterized by incomplete knowledge of the molecular mechanisms underlying their occurrence and the lack of valid biomarkers and effective treatments. For these reasons, the design of therapies that prevent or delay the onset, slow the progression, or improve the symptoms associated to these disorders is urgently needed. During the last few decades, translational research provided a framework for advancing development of new diagnostic devices and promising disease-modifying therapies for patients with prion encephalopathies and AD. In this review, we provide present evidence of how supportive can be the translational approach to the study of dementias and show some results of our preclinical studies which have been translated to the clinical application following the 'bed-to-bench-and-back' research model.
Topics: Alzheimer Disease; Animals; Humans; Prion Diseases; Translational Research, Biomedical
PubMed: 29172000
DOI: 10.3233/JAD-170770 -
American Journal of Alzheimer's Disease... Aug 2019Alzheimer's disease (AD), a neurological disorder, is as a complex chronic disease of brain cell death that usher to cognitive decline and loss of memory. Its prevalence... (Review)
Review
Alzheimer's disease (AD), a neurological disorder, is as a complex chronic disease of brain cell death that usher to cognitive decline and loss of memory. Its prevalence differs according to risk factors associated with it and necropsy performs vital role in its definite diagnosis. The stages of AD vary from preclinical to severe that proceeds to death of patient with no availability of treatment. Biomarker may be a biochemical change that can be recognized by different emerging technologies such as proteomics and metabolomics. Plasma biomarkers, 5-protein classifiers, are readily being used for the diagnosis of AD and can also predict its progression with a great accuracy, specificity, and sensitivity. In this review, upregulation or downregulation of few plasma proteins in patients with AD has also been discussed, when juxtaposed with control, and thus serves as potent biomarker in the diagnosis of AD.
Topics: Alzheimer Disease; Biomarkers; Humans
PubMed: 31072117
DOI: 10.1177/1533317519848239 -
Stem Cells Translational Medicine Nov 2017
Topics: Alzheimer Disease; Animals; Humans
PubMed: 28949098
DOI: 10.1002/sctm.12217 -
Journal of Alzheimer's Disease : JAD 2018The Alzheimer center of the VU University Medical Center opened in 2000 and was initiated to combine both patient care and research. Together, to date, all patients... (Review)
Review
The Alzheimer center of the VU University Medical Center opened in 2000 and was initiated to combine both patient care and research. Together, to date, all patients forming the Amsterdam Dementia Cohort number almost 6,000 individuals. In this cohort profile, we provide an overview of the results produced based on the Amsterdam Dementia Cohort. We describe the main results over the years in each of these research lines: 1) early diagnosis, 2) heterogeneity, and 3) vascular factors. Among the most important research efforts that have also impacted patients' lives and/or the research field, we count the development of novel, easy to use diagnostic measures such as visual rating scales for MRI and the Amsterdam IADL Questionnaire, insight in different subgroups of AD, and findings on incidence and clinical sequelae of microbleeds. Finally, we describe in the outlook how our research endeavors have improved the lives of our patients.
Topics: Alzheimer Disease; Biomarkers; Brain; Cohort Studies; Early Diagnosis; Humans; Magnetic Resonance Imaging; Netherlands; Quality Improvement; Surveys and Questionnaires
PubMed: 29562540
DOI: 10.3233/JAD-170850