Jul 29, 2020 - Science

Alzheimer's blood test may detect signs 20 years before symptoms show

A social worker shows a portrait of Prince Charles, Prince of Wales to an elderly woman during a memory activity on August 2, 2012 in Barcelona, Spain
A social worker shows a photo of Britain's Prince Charles to a woman during a memory activity at the Cuidem La Memoria elderly home, which specializes in Alzheimer patients, in Barcelona, Spain. Photo: David Ramos/Getty Images

An international team of researchers has found that a newly developed blood test is highly accurate in aiding the detection of Alzheimer's disease.

Why it matters: The test could distinguish Alzheimer's from other conditions, and may be able to detect changes in the brain 20 years before dementia symptoms occur, per the study findings, published in the Journal of the American Medical Association (JAMA) Tuesday.

What they're saying: Current assessment tools, such as PET scans and spinal fluid analyses, are invasive and costly. Maria Carrillo, chief science officer at the Alzheimer's Association said in a statement that this more affordable and widely available test would be "game changing for individuals, families and our healthcare system."

  • Oskar Hansson, from Lund University in Sweden, said that once verified and confirmed, the test could open up the possibility of early diagnosis of Alzheimer’s before the dementia stage.

What they did: The test measures a form of the tau protein, tangled bundles of fibers that spread in the brains of Alzheimer's patients, in more than 1,400 cases involving groups from the U.S., Sweden and Colombia.

Yes, but: Scientists are still trying to determine the role of tau proteins in Alzheimer's and so more long-term testing is needed on a larger scale, such as clinical trials.

The bottom line: Carrillo noted that while these early results, presented at the Alzheimer’s Association International Conference on Tuesday, are encouraging, "we do not yet know how long it will be until these tests are available for clinical use."

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