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A Blood Test for Alzheimer's?

A Blood Test for Alzheimer's?
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July 28, 2020
Alzheimer’s Association Contact, 401-.421.0008,
AAIC 2020 Press Office,
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CHICAGO, JULY 28, 2020 — A simple blood test for Alzheimer’s would be a great advance for individuals with — and at risk for — the disease, families, doctors and researchers. At the Alzheimer’s Association International Conference® (AAIC®) 2020, scientists reported results of multiple studies on advances in blood “tests” for abnormal versions of the tau protein, one of which may be able to detect changes in the brain 20 years before dementia symptoms occur. 
In particular, the reports focus on a specific form of tau known as p-tau217, which seems to be the most specific to Alzheimer’s and the earliest to show measurable changes. Changes in brain proteins amyloid and tau, and their formation into clumps known as plaques and tangles, respectively, are defining physical features of Alzheimer’s disease in the brain. Buildup of tau tangles is thought to correlate closely with cognitive decline. In these newly reported results, blood/plasma levels of p-tau 217, one of the forms of tau found in tangles, also seem to correlate closely with buildup of amyloid. 

Currently, the brain changes that occur before Alzheimer’s dementia symptoms appear can only be reliably assessed by positron-emission tomography (PET) scans, and from measuring amyloid and tau proteins in spinal fluid (CSF). These methods are expensive and invasive. And, too often, they are unavailable because they are not covered by insurance or difficult to access, or both. 

“There is an urgent need for simple, inexpensive, non-invasive and easily available diagnostic tools for Alzheimer’s. New testing technologies could also support drug development in many ways. For example, by helping identify the right people for clinical trials, and by tracking the impact of therapies being tested,” said Maria C. Carrillo, Ph.D., Alzheimer’s Association chief science officer. “The possibility of early detection and being able to intervene with a treatment before significant damage to the brain from Alzheimer's disease would be game changing for individuals, families and our healthcare system.”

 A blood test, for example, will enable interpretation and understanding of Alzheimer’s progression in much larger, more diverse and more robust populations. 
“While these new reports are encouraging, these are early results, and we do not yet know how long it will be until these tests are available," said Donna M. McGowan., Executive Director of the Alzheimer's Association Rhode Island Chapter. "There is more work to be done to prepare for the next stage."

Local researchers from the Ocean State participating in the conference also felt buoyed by the findings.

"The development of valid "blood tests" for Alzheimer's disease is essential to improve diagnosis, particularly at the earliest stages of the disease when the challenges of accurate diagnosis and the potential benefits of disease modifying treatments are the greatest.  Such biomarker tests are much needed to accelerate the development of new therapies and help us track the biological response  to treatment in patients in clinical trials," said Brian R. Ott, MD, Professor of Neurology, Alpert Medical School of Brown University and Director of the Alzheimer's Disease & Memory Disorders Center, Rhode Island Hospital. "It is not a question of whether we will have one or more valid blood tests to diagnosis and follow the course of Alzheimer's disease, but when.  I look forward to  seeing the results of larger scale longitudinal studies for verification of these exciting preliminary results."


"The advances in blood tests for Alzheimer’s disease reported at AAIC are very exciting," said Stephen Salloway, Director of Neurology and the Memory and Aging Program at Butler Hospital. "Once validated, these tests will be a game changer in Alzheimer’s research providing an economical way to screen for Alzheimer’s prevention and treatment trials.”  

For further abstract on this research and for interviews with Rhode Island researchers and Alzheimer’s Association staff please contact Eric Creamer at 401-859-2334 or email at

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