Blood test could diagnose Alzheimer's disease

October 5, 2010, UT Southwestern Medical Center

A set of proteins found in blood serum shows promise as a sensitive and accurate way to diagnose Alzheimer's disease, researchers at UT Southwestern Medical Center have found as part of a statewide study.

An analysis of the proteins, plus a clinical exam, proved 94 percent accurate in detecting suspected Alzheimer's and 84 percent accurate in ruling it out in people without the disease, the researchers said.

"This research uses a novel technology that makes it possible to analyze several in a single in a cost-effective way," said Dr. Ramón Díaz-Arrastia, professor of neurology at UT Southwestern and senior author of the study which was published in the September issue of the Archives of Neurology.

Researchers have been seeking a simple blood test for Alzheimer's for years, Dr. Díaz-Arrastia said, but no single substance, or "biomarker," has been shown to be useful. Such a test, he said, would be comparable in principle to measuring blood cholesterol as a biomarker of cardiovascular disease.

is an incurable degenerative brain disease, which currently afflicts about 5.3 million people over 65 in the U.S., according to the National Alzheimer's Association. By 2050 that number is expected to reach 11 million or more.

The disease is difficult to diagnose, particularly in its early stages when it resembles other cognitive problems. Currently, a definitive diagnosis is possible only after examining the brain tissue of deceased individuals. Tests for suspected Alzheimer's are often expensive or invasive, and not every patient is able or willing to undergo them, the researchers stated.

A blood test would provide a convenient diagnostic method that could be performed by health care workers nearly anywhere. In addition, a definitive diagnosis is important because treatments specifically targeting Alzheimer's might not be effective against other forms of neurodegenerative disease or cognitive decline, Dr. Díaz-Arrastia said.

Researchers associated with the Texas Alzheimer's Research Consortium, a five-university group funded by the state, carried out the research. In the current study, the scientists analyzed blood samples from 197 Texas patients who had suspected Alzheimer's and 203 people without the disease.

The researchers measured more than 100 blood proteins and created a mathematical analysis that could measure a person's risk of having Alzheimer's. The analysis, combined with information from a clinical exam, accurately detected Alzheimer's 94 percent of the time, and correctly ruled out Alzheimer's 84 percent of the time in people without the disease, Dr. Díaz-Arrastia said.

Neither the blood test nor a clinical exam alone was as accurate on its own as the blood test and clinical exam combined, the researchers found.

"Having a diagnosis is an important step, but it's not the end of the road unless you've got a treatment or a cure," Dr. Díaz-Arrastia said.

The next step in the work is to determine whether the biomarker test can detect accurately Alzheimer's in preserved from patients who have been diagnosed definitively by an autopsy.

Related Stories

Recommended for you

Study finds alcohol dampens brain waves associated with decision-making but not motor control

March 15, 2018
We all know that alcohol impairs our judgement, alertness and performance on tasks requiring attention, but the mechanism behind booze's effect on cognition still isn't well-understood. Now, a new study led by psychologists ...

Breakthrough discovery in neurotransmission

March 15, 2018
Samir Haj-Dahmane, Ph.D., senior research scientist at the University at Buffalo Research Institute on Addictions, has discovered how certain neurotransmitters are transported and reach their targets in the brain, which could ...

Research reveals brain mechanism involved in language learning

March 15, 2018
Learning a new language may be more of a science than an art, a University of Sussex study finds.

New research sheds light on underlying cause of brain injury in stroke

March 15, 2018
New research shows how the novel drug QNZ-46 can help to lessen the effects of excess release of glutamate in the brain – the main cause of brain injury in stroke.

New tissue technique gives stunning 3-D insights into the human brain

March 15, 2018
Imperial researchers have helped develop a breakthrough imaging technique which reveals the ultra-fine structure of the brain in unprecedented detail.

Cell therapy could improve brain function for Alzheimer's disease

March 15, 2018
Like a great orchestra, your brain relies on the perfect coordination of many elements to function properly. And if one of those elements is out of sync, it affects the entire ensemble. In Alzheimer's disease, for instance, ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.