A research team at the University of Tokyo said Thursday it has detected accumulations of proteins believed to cause Alzheimer's in blood samples taken from Japanese people with mild or no symptoms, potentially allowing easier and earlier detection of the disease.
The findings, based on the first large-scale study targeting Japanese people, may lead to more efficient diagnosis of early-stage Alzheimer's, believed to be caused when amyloid beta and tau proteins accumulate inside the brain and destroy nerve cells.
The achievement, published in Alzheimer's Research and Therapy journal, comes when a new Alzheimer's drug developed by Japanese company Eisai Co and U.S. firm Biogen Inc was launched in Japan last year for people with accumulations of amyloid beta proteins.
To use the therapy, branded Leqembi, sufferers currently need to be checked for accumulation of the protein through a scan, and by examination of cerebrospinal fluid extracted from the waist area with a long needle.
But the methods are costly and physically painful, while medical institutions that can offer the service in Japan are limited. Diagnosis through blood tests could be a big step forward, the team said.
In the study, the University of Tokyo team took blood samples from 474 Japanese diagnosed as suffering either mild cognitive impairment or without such symptoms. The group's amyloid beta and tau protein levels were measured.
The team then used the measurements in conjunction with clinical information, such as age and sex, to predict results obtained through scans. The team's predictions matched the scans with a high level of accuracy.
Takeshi Iwatsubo, the University of Tokyo professor who led the study, said finding the accumulation of the proteins in an asymptomatic person was previously "believed to be difficult."
Although a diagnosis of Alzheimer's disease still needs to be confirmed by scans and other tests, "I hope the study would lead to a very early diagnosis using blood tests in the future," he said.
Alzheimer's is the most prevalent form of dementia. One study projects that 4.71 million elderly people in Japan will be affected by dementia by 2025 and 6.45 million by 2060, representing approximately one in six individuals aged 65 and above.
