A simple technique to measure the amount of amyloid beta in the brain could improve diagnosis and drug trials for Alzheimer’s disease, according to the results of new research.
A simple blood test
Japanese researchers led by Dr. Katsuhiko Yanagisawa have published a new study suggesting that a screening test could help to boost the success rate of Alzheimer’s drug research. The research team has shown that a simple blood test can accurately measure the amount of amyloid beta, a protein that appears in the early stages of Alzheimer’s disease.
Amyloid is a typical pathological feature of Alzheimer’s disease, so being able to discern how much amyloid is present is key when designing optimal clinical trials. Currently, the only way to measure amyloid accumulation in a living person is either via an expensive positron emission tomography imaging (PET scan) or by taking a sample of cerebrospinal fluid (CSF) via a lumbar puncture, or spinal tap. A blood test would be a far less invasive and costly procedure to help determine how much amyloid is present in a patient.
The researchers believe that suficient amounts of amyloid beta penetrate the blood-brain barrier and enter the bloodstream to be a reliable measure of cognitive function. The hope is to replace the current, costly analysis methods with a simple, cost-effective way to detect preclinical Alzheimer’s and disease progression while improving clinical trials.
In order to measure the amyloid present in the bloodstream, the research team used a technique known as immunoprecipitation with mass spectrometry, which uses antibodies to bind to target proteins. The study included 121 people from Japan and 252 from Australia; of this group, there were people with normal brain function, mild cognitive impairment and Alzheimer’s disease.
The researchers noted that the amount of amyloid present in the bloodstream correlated directly with the level of cognitive impairment. The level of blood amyloid also correlated with results from PET scans and spinal fluid samples from the same patients; this confirms that the blood test is effective.
The researchers are now continuing their study and expanding it in the hopes that they can bring an amyloid blood test closer to standard clinical use.
Having a reliable, non-invasive, and cost-effective biomarker for Alzheimer’s disease is a great result for clinical trials and drug development and may even find utility with home users who wish to monitor their health. We wish the researchers the best of luck and hope that soon, this test will be accepted as standard medical practice.
 Akinori Nakamura, Naoki Kaneko, Victor L. Villemagne, Takashi Kato, James Doecke, Vincent Doré, Chris Fowler, Qiao-Xin Li, Ralph Martins, Christopher Rowe, Taisuke Tomita, Katsumi Matsuzaki, Kenji Ishii, Kazunari Ishii, Yutaka Arahata, Shinichi Iwamoto, Kengo Ito, Koichi Tanaka, Colin L. Masters & Katsuhiko Yanagisawa (2018). High performance plasma amyloid-β biomarkers for Alzheimer’s disease. Nature doi:10.1038/nature25456