Groundbreaking Blood Test for Alzheimer’s Shows High Accuracy in Early Detection
Researchers have made a significant stride in Alzheimer's disease detection with a new blood test that screens for a protein called phosphorylated tau (p-tau), demonstrating remarkable accuracy in identifying key Alzheimer’s biomarkers before symptoms manifest.
This innovative approach, focusing on the p-tau217 biomarker, aligns with the accumulation of harmful proteins—beta amyloid and tau—in Alzheimer's patients' brains. Traditional methods like brain scans or spinal taps, often costly and less accessible, are currently employed for this purpose.
Published in JAMA Neurology, the study reveals the test's precision—96% in detecting elevated beta amyloid and 97% for tau. Nicholas Ashton, a neurochemistry professor at the University of Gothenburg and a lead author, expresses confidence in the blood test’s capabilities, aligning with the scientific community's longstanding belief in such biomarkers' potential.
AD-Detect, the first commercial blood test for beta amyloid assessment in the U.S., was introduced last year. While it doesn't diagnose Alzheimer's, it aids in risk assessment. However, some experts remain skeptical about its scientific basis.
The new test, ALZpath pTau217 assay, developed by ALZpath, has been pivotal in this research. Currently, it's only available for research but is expected to enter clinical use soon. Its estimated cost ranges between $200 and $500.
This assay could redefine cognitive impairment assessments, especially where advanced testing is limited, offering a more efficient and early Alzheimer's diagnosis. It shows remarkable accuracy in identifying patients who might benefit from targeted therapies like Leqembi and Aduhelm.
Involving 786 participants, the study compared the blood test's results with traditional brain scans and spinal taps, finding similar accuracy. Approximately 80% of participants received definitive results from the blood test alone, reducing the need for more invasive and costly examinations.
Despite its high accuracy, the test is not infallible. A negative result doesn't rule out other cognitive impairment forms like vascular dementia or Lewy body dementia. Also, not everyone with Alzheimer’s markers develops the disease.
According to preventive neurologist Dr. Richard Isaacson, this test is akin to routine cholesterol tests for early detection and management of heart disease. As Alzheimer’s changes occur about 20 years before symptoms, early blood-based detection could be crucial.
Symptoms of Alzheimer's vary but commonly include memory issues like losing track of dates or misplacing items. Early detection through such blood tests could revolutionize Alzheimer’s management and treatment strategies.
