Blood Proteins May Provide Early Clue to Alzheimer's

Findings could offer possible ways to diagnose, treat the disease sooner, researchers say

By Robert Preidt

Wednesday, June 10, 2015

WEDNESDAY, June 10, 2015 (HealthDay News) -- Certain brain proteins can be detected in the blood of people long before they develop Alzheimer's disease and may offer a way to diagnose and treat the disease earlier, a new study suggests.

The proteins -- called lysosomal proteins -- play a role in the removal of damaged nerve cell material. The researchers discovered that blood levels of these proteins were higher in people with normal memory and thinking abilities up to 10 years before they developed Alzheimer's disease.

The findings were published online June 10 in the journal Neurology.

"These proteins are in very tiny nerve cell-derived blood particles called exosomes," study author Dr. Edward Goetzl explained in a journal news release. "Abnormal levels of the proteins may be useful [signals] that could help us study early treatments to limit or reverse the damage to brain cells and even prevent the development of the full-blown disease."

Goetzl is professor of medicine with the University of California, San Francisco, and a researcher at the U.S. National Institute on Aging.

To find the proteins, Goetzl and his colleagues looked at blood samples taken from 20 people who later went on to develop Alzheimer's disease. The blood samples were taken up to 10 years before the people were diagnosed with the disease, the researchers said. They also looked at blood samples from people who already had Alzheimer's disease and people with a different type of dementia. Then they compared these samples to blood samples from 46 healthy people.

"The results also show us that there are major abnormalities in how these proteins function in brain cells, which could potentially provide a new target for treatments," added Goetzl, who's also a scientist at NanoSomiX Inc., a California-based biotechnology company that provided funding for the study.

"These results may help improve our understanding of how lysosomes function in Alzheimer's disease and may help us understand how the brain responds to the developing disease," he said.

Still, Goetzl noted, this was an early study with only a small number of patients. He added that the findings need to be confirmed in larger studies.

One Alzheimer's expert agreed that the findings are early, but promising.

"This is a small study with powerful implications," said Dr. Allison Reiss, head of the Inflammation Section at Winthrop-University Hospital in Mineola, N.Y.

"We know that the groundwork for Alzheimer's disease is laid many years before symptoms appear, but predictive tests to tell us who will develop the disease have not yet been developed," Reiss explained.

"More work is necessary, but these results are an encouraging first step," she said. "The ability to detect incipient Alzheimer's disease opens up an opportunity to change the course of this devastating disorder."

Another expert said the work is promising, but it's too early to be of use to the average person, given that there are currently no effective ways to prevent or treat Alzheimer's disease.

"I would advise against routine screening [using this test]," said Dr. Paul Wright, chair of neurology at North Shore University Hospital in Manhasset, N.Y., and at Long Island Jewish Medical Center in New Hyde Park, N.Y.

"I feel that having information that you may develop Alzheimer's 10 years from now would result in a significant psychological burden," he said. "This may result in depression and potentially a detrimental change in lifestyle. Routine screening would be more appropriate if a cure was available and early recognition was critical."

SOURCES: Allison Reiss, M.D., head of the Inflammation Section, Winthrop-University Hospital, Mineola, N.Y.; Paul Wright, M.D., chairman of neurology, North Shore University Hospital, Manhasset, N.Y., and Long Island Jewish Medical Center, New Hyde Park, N.Y.; Neurology, news release, June 10, 2015

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