Diagnosing Alzheimer's: New Blood Test Suggests Possible Breakthrough

Diagnosing Alzheimer’s:

New Blood Test Suggests Possible Breakthrough

Boston--A new blood test that has the potential to diagnose Alzheimer’s disease in an individual and significantly advances drug testing and research on the disease, has been developed through grant funding by the Cure Alzheimer's Fund.

The test, known as "I.S." for "Immunosignature" and developed by a team led by UCLA neurologist Lucas Restrepo, uses a special method of fluorescent tagging of antibodies in the blood to recognize an identifiable binding pattern -or antibody "signature" - associated with Alzheimer's. 

In their study to be presented at the 2014 American Academy of Neurology Meeting in Philadelphia, Restrepo and colleagues were able to use the test to distinguish Alzheimer's patients from elderly people without dementia with 95% accuracy.

“This is an important contribution to Alzheimer’s research,” said Rudy Tanzi, chairman of the Cure Alzheimer’s Research Consortium. “We cannot treat what we can’t diagnose, and Alzheimer’s research has been severely restricted by our ability to reliably, consistently and precisely diagnose this disease in all its progressive stages. If these results are confirmed, I.S. could be used to make diagnosis easier and swifter, and for researchers to test potential therapies much faster and more effectively.”

Alzheimer's diagnosis has been a daunting problem for the medical profession. For many years, there were no even marginally-reliable biomarker tests to determine if someone had the disease.

Over the last decade, researchers have developed somewhat reliable methods using Cerebrospinal Fluid (CSF) profiling of tau and beta-amyloid proteins, and radioactive compounds combined with PET imaging. These methods, however, are cumbersome and expensive, leaving the research and medical communities eager to develop a cheaper and more reliable test - ideally a quick, and easy blood test.

In March, a team led by Howard Federoff at Georgetown University Medical Center announced, in the journal Nature Medicine, another new blood test that seems to successfully predict future onset of Alzheimer's. Federoff's test is based on a different sort of "signature" comprised of ten different fats in the bloodstream. 

Restrepo and his colleagues had the idea to focus on antibodies because Alzheimer's is known to be associated with markers of inflammation in the brain and blood stream. "We thought that detecting antibodies might be promising, as these are markers of diseases that a person has been exposed to," said Dr. Restrepo, a neurologist at UCLA's David Geffen School of Medicine, "but I was frankly surprised that we were able to discern such a unique signature. I'm grateful for the support from Cure Alzheimer's Fund, and hopeful that this discovery will help both accelerate the pace of research and improve the care in the Alzheimer's community." 

Restrepo's colleagues on this study were the inventors of the microarray used as the platform for the I.S. test, Drs. Phillip Stafford and Stephen Albert Johnston, from the Biodesign Institute at Arizona State University in Tempe, Arizona.

"The outcome of this study hopefully provides people another tool to target the disease earlier, before irreversible brain damage or mental decline has occurred," said Cure Alzheimer's chairman Jeffrey Morby. "Getting out in front and funding smart but risky studies like this one is what we're built to do. You can't have dramatic success like this without taking big, smart risks."