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A recent study suggests that a blood test for a protein called phosphorylated tau (p-tau) could be a highly accurate screening tool for Alzheimer’s disease, even before symptoms appear. The study focused on a biomarker known as p-tau217, which increases as damaging proteins associated with Alzheimer’s, such as beta-amyloid and tau, accumulate in the brain. Unlike current methods involving brain scans or spinal taps, this blood test demonstrated up to 96% accuracy in identifying elevated beta-amyloid levels and up to 97% accuracy in identifying tau.
The lead author, Professor Nicholas Ashton, highlighted that the blood test’s accuracy was comparable to advanced methods like cerebrospinal fluid tests and brain scans. The test, known as the ALZpath pTau217 assay, is commercially available for research purposes, and it is expected to be available for clinical use soon.
The study involved 786 participants, with the blood test showing similar accuracy in identifying abnormalities as spinal taps or brain scans. The blood test reduced the need for further, costly examinations in about 80% of cases, making it a promising tool for early dementia investigation.
While this blood test is specific to Alzheimer’s disease, it may not identify other potential causes of cognitive impairment. The researchers emphasize the test’s potential in guiding treatment decisions, particularly for therapies targeting beta-amyloid.
The ALZpath pTau217 assay’s estimated cost is between $200 and $500, offering a more accessible alternative to current diagnostic methods. Preventive neurologist Dr. Richard Isaacson believes that routine blood tests for Alzheimer’s, like cholesterol tests for heart health, could become a standard practice, providing individuals with valuable time to make brain-healthy choices and discuss risk factors with their doctors. This blood test could play a crucial role in the early detection of Alzheimer’s, allowing for proactive management and potentially paving the way for effective treatments in the future.
