Japanese and Australian researchers have developed a simple and affordable blood test to diagnose Alzheimer’s disease, they reported in the science journal Nature on Wednesday.
The new method to check the buildup of a protein in the brain, which is believed to be linked to the disease, will potentially enable “broader clinical access and efficient population screening,” said the team that includes Nobel chemistry laureate Koichi Tanaka of Shimadzu Corp.
While the cause of Alzheimer’s, the most common form of dementia, is not exactly known, abnormal buildup of the protein amyloid-beta is said to be one of the factors that lead to its development.
The accumulation of the protein is currently checked using highly invasive methods, such as positron-emission tomography scans — also known as a PET scans — and through the examination of cerebrospinal fluids extracted from the waist using long needles. The methods are costly and painful.
“We may be able to use this (new) method broadly in medical examinations for the elderly if it becomes possible to cure or prevent Alzheimer’s,” said Katsuhiko Yanagisawa, director-general of the Research Institute of the National Center for Geriatrics and Gerontology in Aichi Prefecture.
The research was conducted in collaboration with the Australian Imaging, Biomarker and Lifestyle Flagship Study of Ageing along with three Japanese universities.
According to the researchers, amyloid-beta starts accumulating in the brain about 20 to 30 years before the development of Alzheimer’s, and the buildup is believed to increase the risk of developing the disease.
The team thinks the newly developed method may be eventually used to check the likelihood of getting the disease.
In the study, the team found a way to extract substances related to amyloid-beta from 0.5 milliliter of blood and to measure the substances with mass spectrometry technology developed by Tanaka and others.
The buildup of amyloid-beta can be confirmed from the ratio of the related substances, which can be separated into three types using an antibody.
The team also confirmed that the outcome of the study matched around 90 percent of the results using the invasive PET scans in a survey that covered 232 people in Japan and Australia aged from 60 to 90. The people included those with Alzheimer’s and those with no health issues.
The findings drew mixed reactions from relatives of people with dementia and support groups. Some said the method would enable people to get treated earlier, while others expressed concerns that, with no cure in place, an early diagnosis of dementia might lead to despair for people with dementia and their families.
Masami Yoshida, 73, the leader of a support group based in the city of Kakogawa, Hyogo Prefecture, welcomed the news. Yoshida’s 73 year-old wife was diagnosed with Alzheimer’s 10 years ago. He has since been nursing her at home.
“An early diagnosis means earlier treatment. And families can prepare for a new lifestyle and environment both mentally and physically,” Yoshida said.
But Morio Suzuki, 66, the representative director of Alzheimer’s Association Japan, said that people diagnosed as having a greater chance of developing dementia might fall into despair.
“What’s important is that we need to build a society and a system where people who are diagnosed with dementia can keep living the lives they want to live,” he said.
Shimadzu, based in Kyoto, plans to start a blood analyzing service for drugmakers and researchers.
Alzheimer’s is a type of dementia that causes problems with memory and other cognitive abilities serious enough to interfere with daily life. Medicine can temporarily slow progress of the symptoms, but at present, there is no treatment to completely cure the disease.
In rapidly aging Japan, more than 5 million elderly people are struggling with dementia, and the number is expected to exceed 7 million by 2025. More than 60 percent of them have Alzheimer’s.
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