Amyloid beta deposits, or plaques, in the brain are the most commonly hypothesized causative agent behind Alzheimer's disease. A new breakthrough blood test, developed by an international team of scientists, can reportedly measure the concentration of these amyloid beta concentrations using just a tiny blood sample.

One of the big challenges currently facing many Alzheimer's researchers is the difficulty in diagnosing the disease during its early, preclinical stages. Inherent to the hypothesis that amyloid plaques in the brain are one of the main causes of the disease, is the notion that these plaques often build up slowly, over 10 or 20 years, before clinical signs like memory loss become apparent.

Current testing for amyloid beta deposits in the brain is an onerous, expensive and invasive process, either involving costly positron emission tomography (PET) scans, or analyzing cerebrospinal fluid extracted via lumbar puncture. Until now, there has been no accurate way to track these deposits from a simple blood test.

The new blood test, developed by scientists from Japan and Australia, was tested on several hundred patients and found to be 90 percent accurate in predicting whether a person had an abnormal build up of amyloid beta in their brain.

"From a tiny blood sample, our method can measure several amyloid-related proteins, even though their concentration is extremely low," says Koichi Tanaka from the Shimadzu Corporation. "We found that the ratio of these proteins was an accurate surrogate for brain amyloid burden."

It's still early days for the research with more testing necessary before the blood test would be deployed into practice for the general public, but a more immediate use could be in evaluating participants for Alzheimer's related clinical trials. Colin Masters, from the Florey Institute of Neuroscience & Mental Health and co-lead on the research, suggests the test will, "be an invaluable tool in increasing the speed of screening potential patients for new drug trials."

So while we don't have any effective singular treatment for Alzheimer's currently, this blood test will hopefully speed up research by making clinical trials more effective. Following on from that, a simple way to screen for the disease, years before any symptoms actually appear, will help patients apply countermeasures to battle the deleterious effect of these amyloid beta concentrations.

"I can see in the future, five years from now, where people have a regular checkup every five years after age 55 or 60 to determine whether they are on the Alzheimer's pathway or not," Masters optimistically told The Guardian.

The research appears in the journal Nature.

Source: Florey Institute of Neuroscience & Mental Health