A Blood Test for Alzheimer's?

Sept. 8. 2008— -- New research released Monday touts a potential blood test to predict which people are at risk for developing Alzheimer's disease. But experts overwhelmingly agree that the test might not be such a reliable screening tool for Alzheimer's -- and is certainly not ready for prime time.

The study looked at a potential biomarker for Alzheimer's disease -- a protein called ABeta42. Researchers at Columbia University performed blood tests on more than 1,100 elderly patients to examine the relationship between the amount of ABeta42 in a person's blood and their likelihood of developing Alzheimer's. They found that those with high levels of this protein were three times as likely to develop Alzheimer's over a five-year period.

"Our results suggest individuals with [higher ABeta42 levels] are at increased risk of [Alzheimer's disease]," the researchers note in the study, published in the Proceedings of the National Academy of Science.

The study authors surmise that the connection may be useful in determining who may be at higher risk of developing the condition -- and might even lead to a diagnostic test to catch it early.

But Alzheimer's disease researchers not affiliated with the study overwhelmingly disagree that this discovery moves scientists any closer to developing a truly reliable blood biomarker screening tool for the disease.

"[This research] doesn't appear to move us closer [to a blood screening test for Alzheimer's]," said Dr. Myron Weiner, clinical professor of psychiatry and neurology at the UT Southwestern Medical Center in Dallas. "We probably need to explore other potential markers [other] than ABeta42."

Currently, experts depend on a series of brain scans and psychological tests to diagnose Alzheimer's disease. However, such a test is only successful in diagnosing patients who already have symptoms. Thus, the current struggle within the Alzheimer's community is to develop a screening tool that can predict who will develop the condition before symptoms start.