Taiwan doctors help develop 90% accurate Alzheimer's blood test

Taipei, April 17 (CNA) Taipei Veterans General Hospital (TVGH) on Wednesday announced a research breakthrough that enables a simple blood test to detect individuals at high risk of Alzheimer's disease with around 90 percent accuracy by analyzing specific proteins in blood plasma.

One in every 12 people in Taiwan aged 65 and above is at risk of dementia, Fuh Jong-ling (傅中玲), deputy head of TVGH's Department of Neurology, Neurological Institute, said at a news conference held at the hospital in Taipei.

Alzheimer's disease is the leading cause of dementia, accounting for 56.88 percent of cases, according to a report published by the Ministry of Health and Welfare (MOHW) in 2024 and cited by Fuh.

Alzheimer's is caused by the accumulation of proteins in the brain that leads to the death of neurons and has two key pathological features in the brain, Fuh said.

The first and most prominent feature is amyloid plaques -- unusual clumps of a protein called beta amyloid found between nerve cells -- the second, though also significant, is neurofibrillary tangles -- bundles of twisted filaments found within neurons, largely made up of a protein called tau, according to Fuh.

She said that in the past, diagnosing Alzheimer's disease relied heavily on cerebrospinal fluid analysis or positron emission tomography (PET) scans.

Both are invasive and expensive -- NT$70,000 (US$2,152) for a PET scan -- limiting public access to the two diagnostic tools, Fuh added.

However, a team formed by researchers from Taiwan and South Korea -- including Fuh and Lin Yung-shuan (林詠萱) of TVGH -- found a strong correlation between phosphorylated tau proteins (p-tau) in blood plasma and the accumulation of amyloid plaques in the brain, paving the way for a more cost-effective and less invasive method of early detection.

They discovered that p-tau217 -- a variant of p-tau that differs from others in its phosphorylation sites -- demonstrated greater accuracy in predicting early-stage Alzheimer's disease than the previously used p-tau181, Fuh said.

In January, the team tested a total of 270 participants from Taiwan and South Korea, including healthy individuals, people with mild cognitive impairment, and dementia patients, she said.

By comparing blood test results with PET scans, the researchers found that the higher the concentration of p-tau217 in blood plasma, the more likely the individual was to be associated with Alzheimer's disease, Fuh added.

Among those deemed high-risk by the blood test, 86 percent were confirmed to have Alzheimer's disease through PET scans, while among those classified as low-risk, 97 percent were found to be free of it, Fuh said.

"This can really help the public in several ways," Fuh said, noting that those identified by the blood test as low-risk individuals do not need to undergo further testing, while those classified as high-risk individuals are likely to have Alzheimer's disease and should receive treatment.

She added that the findings also suggest that in the future, only individuals classified as medium-risk may need further PET scans, which could reduce unnecessary and costly testing while enabling earlier detection.

Fuh said she hopes blood tests will become a first-line screening tool in the future, helping guide elderly individuals to seek medical attention as early as possible after showing symptoms such as memory decline.

The research finding by the Taiwan-South Korean team was featured in an article titled "Cross-cultural validation of plasma p-tau217 and p-tau181 as precision biomarkers for amyloid PET positivity: An East Asian study in Taiwan and Korea," which was published by Alzheimer's & Dementia, an international medical journal, in late January.