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minutesATLANTA — A recent study indicates that testing a person’s blood for a protein called phosphorylated tau, or p-tau, could potentially be used to screen for Alzheimer’s disease with “high accuracy,” even before symptoms appear.The study involved screening blood for a crucial Alzheimer’s biomarker called p-tau217, which increases alongside other harmful proteins — beta amyloid and tau — in the brains of individuals with the disease. At present, patients typically undergo a brain scan or spinal tap to identify the buildup of beta amyloid and tau, which can be inaccessible and expensive.However, this simple blood test was discovered to be up to 96% accurate in identifying elevated levels of beta amyloid and up to 97% accurate in identifying tau, as per the study published Monday in the journal JAMA Neurology.”The impressive results show that the blood test was just as accurate as advanced testing like cerebrospinal fluid tests and brain scans in indicating Alzheimer’s disease pathology in the brain,” remarked Nicholas Ashton, a professor of neurochemistry at the University of Gothenburg in Sweden and one of the study’s lead authors.The study findings were not surprising to Ashton, who stated that the scientific community has recognized for several years the potential to assess Alzheimer’s disease risk using blood tests to measure tau or other biomarkers.”Now we are close to these tests being prime-time and this study shows that,” he said. Alzheimer’s disease, a brain disorder that affects memory and thinking skills, is the most common type of dementia, according to the National Institutes of Health.Blood test ‘definitive’ in 80% of participantsThe study consisted of data from 786 individuals, with an average age of 66, who underwent brain scans and spinal taps, as well as providing blood samples.Some participants displayed signs of cognitive decline during data collection, while others did not. From February to June of last year, researchers from institutions in Sweden, the United States, and other countries analyzed the participants’ data.The researchers found that when they tested a participant’s blood sample with the p-tau217 immunoassay, the blood test yielded similar results and accuracies in identifying abnormal beta amyloid and tau as the results from the participant’s spinal tap or brain scan. Only about 20% of the study participants had blood test results that, in a clinical setting, would have required further testing with imaging or a spinal tap due to being unclear.”This is a significant reduction in costly and high-demand examinations,” Ashton said. Based on the study findings, “we think that a blood test and clinical examination can have definitive decision in 80%” of those who are being investigated for early signs of dementia.Despite the blood test’s high accuracy in predicting the key characteristics of Alzheimer’s disease in the brain, not everyone with those characteristics will go on to develop the disease.’Keep Alzheimer’s under better control’Additionally, the p-tau test is specific for Alzheimer’s disease, so if someone tests negative but is showing signs of cognitive impairment, this test cannot determine other possible causes of their symptoms, such as vascular dementia or Lewy body dementia.”A blood test being negative speeds up the investigation for other causes of the symptoms and this is just as important,” Ashton said.Signs and symptoms of Alzheimer’s disease can vary from one person to another, but often memory problems are the first signs of the disease, such as losing track of dates, getting lost, misplacing things or having difficulty completing tasks, such as bathing, reading, or writing.Dr. Richard Isaacson, director of research at the Institute for Neurodegenerative Diseases in Florida, who was not involved in the study, has researched blood biomarkers in people with no or minimal cognitive complaints, likened testing blood samples for signs of Alzheimer’s disease to how people undergo routine blood tests for high cholesterol.”People get cholesterol tests before they have a heart attack. People get cholesterol tests before they have a stroke. To me, this type of test will eventually be best served in people before they start to have cognitive symptoms,” Isaacson said. And “just like cholesterol tests, by following the pTau217 level over time, we can better understand how various therapies and lifestyle changes are working to keep Alzheimer’s under better control.”×Most recent Health storiesMore stories you may be interested in
