May 1, 2013
Alzheimer’s Biomarkers May Allow Early Detection Test And Treatment
Brett Smith for redOrbit.com - Your Universe Online
Researchers from Australia´s Commonwealth Scientific and Industrial Research Organisation“¯(CSIRO) are reporting significant progress in developing a blood test that can predict the onset of Alzheimer´s in an individual.
According to their report in the journal Molecular Psychiatry, the researchers said they have identified several biomarkers that are associated with the toxic build-up of beta amyloid, a brain signaling protein.
"We have a set of blood markers that estimate how much toxic protein people have in their brain," lead author Samantha Burnham told the Australian Broadcasting Corporation (ABC). "We're hoping that this will develop into a population screening test."
To identify the biomarkers, the scientists used data from“¯the“¯Australian Imaging and Biomarkers Lifestyle Study (AIBL), which includes 11,000 people, ages 60 years and older. They specifically focused on blood samples from 270 participants who also had positron emission tomography (PET) brain imaging scans that measured levels of amyloid protein in their brains.
The researchers were able to detect seven proteins in the blood samples that could be used to predict future levels of amyloid in the brain with an 80-percent rate of accuracy.
While the team was able to correctly predict the levels of amyloid protein in the brains of 82 people from a separate study, they were unable to explain the mechanism behind how these biomarkers relate to Alzheimer's disease.
"A recent study from the AIBL team showed that amyloid beta levels become abnormal about 17 years before dementia symptoms appear,” Burnham said in a statement. “This gives us a much longer time to intervene to try to slow disease progression if we are able to detect cases early."
“We hope our continued research will lead to the development of a low cost, minimally invasive population based screening test for Alzheimer´s in the next five to ten years,” she added. “A blood test would be the ideal first stage to help identify many more people at risk before a diagnosis is confirmed more specialized testing (sic).”
Australian neuroscientist Bryce Vissel told ABC that the study´s results looked promising but he cautioned against making too strong of a connection between beta amyloid and Alzheimer´s.
"Regardless of whether the amyloid hypothesis is right or not we actually need to start treatment a lot earlier and we have to find better ways to diagnose the disease,” he said. "No one debates amyloid load is a good indicator of Alzheimer's. Whether it's the cause of Alzheimer's is another issue."
Other studies have repeatedly reinforced the connection between amyloid beta and Alzheimer´s. A recent report from Duke University researchers found that relatives of Alzheimer´s patients have elevated levels of the protein in their spinal fluid. The researchers found that the relatives also have a smaller-than-average hippocampus — the part of the brain associated with memory.
Debilitating memory loss is a primary symptom of Alzheimer´s, according to the Alzheimer´s Association. About 25 million people worldwide currently suffer from the incurable disease, and that number is expected to grow in the coming decades, particularly in the US and Europe as the population ages.