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Diagnosing Dementia—Positive Signs

A new blood test offers promise in the early detection of Alzheimer's.

By Mary Best

What if there were an easy, affordable blood test that could accurately diagnose Alzheimer's disease (AD)—even before symptoms began to show?

Researchers at Stanford University's School of Medicine have taken that first critical step toward one simple blood test for AD. If proven effective, the test will be able to screen patients for AD as early as two to six years before symptoms of the disease surface.

The test identifies changes in a handful of proteins in blood plasma that cells use to convey messages to one another, notes Tony Wyss-Coray, Ph.D., the study's lead author and an associate professor of neurology and neurological sciences at Stanford, in Palo Alto, California.

"Our technology enables us to 'listen' to the chatter of cells communicating with each other and determine if there's anything abnormal," says Dr. Wyss-Coray. "Our data indicate blood contains a highly specific, biological signature that can characterize Alzheimer's disease years before a clinical diagnosis can be made."

Confirming there is a connection between how cells talk to each other and brain changes due to Alzheimer's, Dr. Wyss-Coray and his team found that their blood test could indicate who had Alzheimer's with 90 percent accuracy. They also found it could predict its onset two to six years before symptoms appeared.

Where Does the Research Go from Here?

Since the study's appearance in the November issue of Nature Medicine, response from the medical community has been positive.

"While a lot of work remains to be done, the study's preliminary findings are remarkable," says Stephen Snyder, M.D., program director in the Neuroscience and Neuropsychology of Aging program at the National Institute on Aging, which helped fund the Stanford research. "Studies like these analyzing 'signals' are critical. Even if they don't unlock the mysteries of Alzheimer's, they help to build the research blocks necessary for those that will provide answers—and pay off for AD patients."

Read More "Understanding Alzheimer's" Articles
Understanding Alzheimer's / New NIA Booklet By and For People With Early-Stage Alzheimer's Disease / Diagnosing Dementia-Positive Signs

Fall 2007 Issue: Volume 2 Number 4 Page 11