Alzheimer's Blood Test Serves as a Crystal Ball

WRITTEN BY: Tara Fernandes

You can’t find your car keys, missed an important Zoom meeting, and draw a blank when it comes to planning what to cook for dinner. Just another weekday or red flags indicating the early signs of Alzheimer’s disease? According to a recent study, the answers could lie in a simple blood test.

Oskar Hansson, Professor of Clinical Memory Research at Lund University, Sweden led an international team of neuroscientists and neurologists who banded together as part of the BioFINDER study in search of improved early detection methods for Alzheimer's. 50 million people worldwide have Alzheimer’s or related dementia, but of these, experts suggest only 1-in-4 have been diagnosed. There is no accepted clinical procedure for diagnosing or predicting Alzheimer’s, with doctors typically getting confirmation only after a patient’s death. The presence of telltale amyloid plaques and tau tangles (clumps of misfolded proteins in the spaces between nerve cells) are pathologic markers confirming the devastating neurological condition.

The BioFINDER study identified a new biomarker circulating in the blood — phospho-tau217, or p-tau217 — which holds immense promise in predicting future onset, up to 20 years before cognitive symptoms begin.

"While more work is needed to optimize the assay and test it in other people before it becomes available in the clinic, the blood test might become especially useful to improve the recognition, diagnosis, and care of people in the primary care setting," said Hansson.

The researchers validated the p-tau217 blood test by recruiting over 1,400 participants from Arizona, Sweden, and Columbia who either showed signs of cognitive impairment or not. The assay demonstrated unprecedented accuracy and sensitivity: those with higher p-tau217 blood levels had a higher risk of developing Alzheimer’s. This correlated with clinical data with 98 percent accuracy.

According to Eric Reiman, MD, Executive Director of Banner Alzheimer's Institute in Phoenix and a senior author on the study, this new test has the potential to completely revolutionize the clinical approach to Alzheimer’s. "Blood tests like p-tau217 have the potential to revolutionize Alzheimer's research, treatment and prevention trials, and clinical care," said Reiman, adding, "While there's more work to do, I anticipate that their impact in both the research and clinical setting will become readily apparent within the next two years."