Researchers at Washington University School of Medicine in St. Louis have discovered that a simple blood test measuring the protein p-tau217 could predict not only a person’s risk of Alzheimer’s disease but also the timing of symptom onset. The protein forms tangles in the brain that disrupt communication between nerve cells. While brain scans can detect these tangles, they are often complex and expensive, prompting the research team to explore whether a blood test could provide similar results.
Published in the journal Nature Medicine, the study analyzed data from over 600 older adults enrolled in two long-term Alzheimer’s research projects. By comparing blood samples with participants’ cognitive performance over several years, researchers found that p-tau217 levels rise in a “remarkably consistent” pattern long before memory loss begins. The team created a model using a patient’s age and protein levels to estimate when symptoms will appear, with a margin of error of three to four years.
Lead researcher Kellen K. Petersen, PhD, an instructor of neurology at Washington University, explained that older adults developed symptoms much more rapidly after p-tau217 became abnormal. He noted that “people who first had abnormal p-tau217 levels around age 60 didn’t develop Alzheimer’s symptoms for about 20 years, whereas those who first had abnormal p-tau217 levels around age 80 developed symptoms after only about 10 years.” This suggests that age influences how quickly Alzheimer’s symptoms become apparent.
Potential Clinical Applications
Rebecca M. Edelmayer, PhD, vice president of scientific engagement at the Alzheimer’s Association, told Fox News Digital that the test “could transform how researchers design clinical trials and, eventually, how clinicians identify people at highest risk for cognitive decline associated with Alzheimer’s years before decline begins.” Blood tests are generally less expensive and easier to administer than brain scans or spinal-fluid tests, potentially helping doctors identify candidates for early treatments.
However, researchers cautioned against people taking these tests without medical guidance. “At this point, we do not recommend that any cognitively unimpaired individuals have any Alzheimer’s disease biomarker test,” according to Dr. Suzanne Schindler, a neurologist and co-author at Washington University. Petersen acknowledged that “the current estimate is not yet accurate enough for clinical use or personal medical decision-making, but we expect that it will be possible to create more accurate models.”
The study had limitations, including predictions available only for certain p-tau217 ranges and a research cohort that was relatively healthy, well-educated, and not diverse. Two large clinical trials are now in progress to determine whether people with high p-tau217 levels can benefit from treatment with lecanemab or donanemab, the only approved drugs designed to reduce plaques in the brain associated with Alzheimer’s disease.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://www.foxnews.com/health/alzheimers-symptoms-could-predicted-years-advance-through-one-simple-test