An international team of scientists, including a Japanese Nobel laureate, said a new test on just a teaspoon of blood can detect a protein linked to Alzheimer’s disease with an accuracy rate of 90 percent.

The mass spectrometric technique identifies abnormal proteins called amyloid-beta flowing in blood.

A buildup of these proteins in the brain is believed to cause Alzheimer’s disease. The abnormal proteins can start accumulating 20 to 30 years before the onset of the disease.

“The study results will be a foundation for breakthroughs in various medical technologies, including development of fundamental therapeutic agents,” said Koichi Tanaka, co-winner of the 2002 Nobel Prize in Chemistry and a senior fellow at Kyoto-based Shimadzu Corp.

In addition to the Koichi Tanaka Mass Spectrometry Research Laboratory at Shimadzu, the international team included researchers from the National Center for Geriatrics and Gerontology (NCGG) in Obu, Aichi Prefecture.

Using blood samples of 0.5 cc, the researchers could detect and identify abnormal proteins in subjects’ brains and determine the risk of Alzheimer’s disease.

To confirm the results, the team examined positron emission tomography images of the brains of 232 subjects, including healthy elderly people and those with Alzheimer’s disease, in Japan and Australia.

The scientists found that the method can easily detect accumulation of the protein believed to lead to Alzheimer’s disease. In addition, they said the test could be used as a diagnosis aide.

The blood test would be less expensive than the imaging test, which can cost more than 100,000 yen ($920).

However, a number of hurdles remain.

The presence of the abnormal proteins does not always lead to Alzheimer’s disease, meaning that the test results could cause unnecessary anxiety among those who remain healthy.

Those who undergo the test could also be treated unfairly by insurance companies if the results are spread to a third party.

Furthermore, a method to remove the abnormal proteins from the body has yet to be established.

“Our blood test can help determine the efficacy of therapeutic agents for the time being,” said Katsuhiko Yanagisawa, director-general of the NCGG’s Research Institute. “To widely utilize the method in society, a social consensus is required.”