New Blood Test Tracks Alzheimer’s

A new blood test that tracks the breakdown of nerve cells in the brain in Alzheimer's disease. It is an innovation that is now being presented by researchers at the University of Gothenburg in Sweden, together with colleagues in Italy, Great Britain and the United States.

In recent years, great progress has been made in the development of blood tests, so-called biomarkers, for screening and monitoring various disease processes in Alzheimer's disease. Partly, it has involved identifying amyloid plaques in the brain (formed by the protein beta-amyloid) via blood samples, and in later research also the formation of neurofibrils, small thread-like protein structures that consist of a modified (phosphorylated) form of the nerve cell protein tau.

 

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Decreased Proteins, Not Amyloid Plaques, Tied To Alzheimer’s

New research from the University of Cincinnati (UC) bolsters a hypothesis that Alzheimer’s disease is caused by a decline in levels of a specific protein, contrary to a prevailing theory that has been recently called into question.

The prevailing narrative in the field has stated Alzheimer’s is caused by amyloid plaques in the brain, but Alberto Espay, MD, Andrea Sturchio, MD, and their colleagues hypothesized that plaques are simply a consequence of the levels of soluble amyloid-beta in the brain decreasing. These levels decrease because the normal protein, under situations of biological, metabolic or infectious stress, transform into the abnormal amyloid plaques.

In the current study, the team analyzed the levels of amyloid-beta in a subset of patients with mutations that predict an overexpression of amyloid plaques in the brain, which is thought to make them more likely to develop Alzheimer’s disease.

What we found was that individuals already accumulating plaques in their brains who are able to generate high levels of soluble amyloid-beta have a lower risk of evolving into dementia over a three-year span,” said Espay, professor of neurology in the UC College of Medicine.

Source: https://www.uc.edu/
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https://www.eurasiareview.com/

A New Blood Test Detects Alzheimer’s Dementia with 93 percent Accuracy

A blood test developed at Washington University School of Medicine in St. Louis has proven highly accurate in detecting early signs of Alzheimer’s disease in a study involving nearly 500 patients from across three continents, providing further evidence that the test should be considered for routine screening and diagnosis.

Our study shows that the blood test provides a robust measure for detecting amyloid plaques associated with Alzheimer’s disease, even among patients not yet experiencing cognitive declines,” said senior author Randall J. Bateman, MD,  Professor of Neurology. “A blood test for Alzheimer’s provides a huge boost for Alzheimer’s research and diagnosis, drastically cutting the time and cost of identifying patients for clinical trials and spurring the development of new treatment options,” Bateman said. “As new drugs become available, a blood test could determine who might benefit from treatment, including those at very early stages of the disease.”

Developed by Bateman and colleagues, the blood test assesses whether amyloid plaques have begun accumulating in the brain based on the ratio of the levels of the amyloid beta proteins Aβ42 and Aβ40 in the blood.

Researchers have long pursued a low-cost, easily accessible blood test for Alzheimer’s as an alternative to the expensive brain scans and invasive spinal taps now used to assess the presence and progression of the disease within the brain.

Evaluating the disease using PET brain scans – still the gold standard – requires a radioactive brain scan, at an average cost of $5,000 to $8,000 per scan. Another common test, which analyzes levels of amyloid-beta and tau protein in cerebrospinal fluid, costs about $1,000 but requires a spinal tap process that some patients may be unwilling to endure.

This study estimates that prescreening with a $500 blood test could reduce by half both the cost and the time it takes to enroll patients in clinical trials that use PET scans. Screening with blood tests alone could be completed in less than six months and cut costs by tenfold or more, the study finds.

Source: https://medicine.wustl.edu/

Eyes Provide Peek at Alzheimer’s Disease Risk

Protein deposits in retina and brain appear to parallel possible neurodegeneration, an insight that might lead to easier, quicker detection. Amyloid plaques are protein deposits that collect between brain cells, hindering function and eventually leading to neuronal death. They are considered a hallmark of Alzheimer’s disease (AD), and the focus of multiple investigations designed to reduce or prevent their formation, including the nationwide A4 study.

But amyloid deposits may also occur in the retina of the eye, often in patients clinically diagnosed with AD, suggesting similar pathologies in both organs. In a small, cross-sectional study, a team of researchers, led by scientists at University of California San Diego School of Medicine, compared tests of retinal and brain amyloids in patients from the A4 study and another study (Longitudinal Evaluation of Amyloid Risk and Neurodegeneration) assessing neurodegeneration risk in persons with low levels of amyloid.

Like the proverbial “windows to the soul,” the researchers observed that the presence of retinal spots in the eyes correlated with brain scans showing higher levels of cerebral amyloid. The finding suggests that non-invasive retinal imaging may be useful as a biomarker for detecting early-stage AD risk.

Amyloid deposits tagged by curcumin fluoresce in a retinal scan.

This was a small initial dataset from the screening visit. It involved eight patients,” said senior author Robert Rissman, PhD, professor of neurosciences at UC San Diego School of Medicine. “But these findings are encouraging because they suggest it may be possible to determine the onset, spread and morphology of AD — a preclinical diagnosis — using retinal imaging, rather than more difficult and costly brain scans. We look forward to seeing the results of additional timepoint retinal scans and the impact of solanezumab (a monoclonal antibody) on retinal imaging. Unfortunately we will need to wait to see and analyze these data when the A4 trial is completed.”

The findings published in the journal Alzheimer’s & Dementia.

https://ucsdnews.ucsd.edu/

Brain Metals Drive Alzheimer’s Progression

Alzheimer’s disease could be better treated, thanks to a breakthrough discovery of the properties of the metals in the brain involved in the progression of the neurodegenerative condition, by an international research collaboration including the University of Warwick.

Iron is an essential element in the brain, so it is critical to understand how its management is affected in Alzheimer’s disease. The advanced X-ray techniques that we used in this study have delivered a step-change in the level of information that we can obtain about iron chemistry in the amyloid plaques. We are excited to have these new insights into how amyloid plaque formation influences iron chemistry in the human brain, as our findings coincide with efforts by others to treat Alzheimer’s disease with iron-modifying drugs,” commented Dr Joanna Collingwood, from Warwick’s School of Engineering, who was part of a research team which characterised iron species associated with the formation of amyloid protein plaques in the human brainabnormal clusters of proteins in the brain. The formation of these plaques is associated with toxicity which causes cell and tissue death, leading to mental deterioration in Alzheimer’s patients.

They found that in brains affected by Alzheimer’s, several chemically-reduced iron species including a proliferation of a magnetic iron oxide called magnetite – which is not commonly found in the human brainoccur in the amyloid protein plaques. The team had previously shown that these minerals can form when iron and the amyloid protein interact with each other. Thanks to advanced measurement capabilities at synchrotron X-ray facilities in the UK and USA, including the Diamond Light Source I08 beamline in Oxfordshire, the team has now shown detailed evidence that these processes took place in the brains of individuals who had Alzheimer’s disease. They also made unique observations about the forms of calcium minerals present in the amyloid plaques.

The team, led by an EPSRC-funded collaboration between University of Warwick and Keele University – and which includes researchers from University of Florida and The University of Texas at San Antonio – made their discovery by extracting amyloid plaque cores from two deceased patients who had a formal diagnosis of Alzheimer’s. The researchers scanned the plaque cores using state-of-the-art X-ray microscopy at the Advanced Light Source in Berkeley, USA and at beamline I08 at the Diamond Light Source synchrotron in Oxfordshire, to determine the chemical properties of the minerals within them.

Source: https://warwick.ac.uk/