New Blood Test Can Estimate When Alzheimer’s Symptoms Will Begin, Study Finds
- Alzheimer's disease affects roughly 7 million individuals over the age of 65 in the United States.
- Researchers out of the Washington University School of Medicine in St. Louis found that measuring a protein fragment in the blood can help estimate how long it will take for symptoms to appear.
- Creating a "clock model", researchers utilize p-tau217, the protein fragment, to map disease progression and predict the timing of symptom onset.
A simple research-stage blood test may soon help doctors more accurately estimate when someone will begin to show signs Alzheimer’s disease — years, or even decades, before symptoms start, if validated in further studies.
Researchers at Washington University School of Medicine in St. Louis have found that measuring a protein in the blood called p-tau217 can help estimate how long it will take for cognitive symptoms of Alzheimer’s to appear. Their findings, published in Nature Medicine, suggest that the test could offer a less invasive and more affordable tool for early detection and prevention.
Identifying a Specific Protein
The protein tau, along with beta-amyloid, builds up gradually in the brains of people with Alzheimer’s, damaging nerve cells and impairing memory and cognition over time. By tracking p-tau217 levels in blood plasma, scientists developed “clock models” that map out how the disease progresses — much like counting tree rings to determine a tree’s age.
In Alzheimer’s, there is a buildup of proteins, or amyloid plaques and neurofibrillary tangles, in the brain. This causes brain cells to die over time and the brain to shrink.
“Amyloid and tau accumulate in a consistent pattern,” said lead author Dr. Kellen K. Petersen, a neurology instructor at WashU Medicine. “The age at which they become detectable strongly predicts when someone is going to develop Alzheimer’s symptoms.”
The researchers found that their models could forecast the onset of symptoms with an accuracy of three to four years. For instance, a 60-year-old with elevated p-tau217 may not experience memory loss until about 20 years later, while an 80-year-old with the same biomarker level might develop symptoms about eleven years later.
Researchers found specifically that sex/gender and level of education had no significant effect on their findings. The authors suggest these clock models could help future clinical trials identify participants likely to develop symptoms during the study period.
Alzheimer’s Disease
Alzheimer’s disease, according to Mayo Clinic, is the most common cause of dementia and affects roughly 7 million individuals over the age of 65.
Currently, Alzheimer’s diagnosis often depends on PET brain scans or spinal fluid tests. Those methods are expensive and can be difficult to perform. The new blood test offers a faster, more accessible alternative that could help researchers screen patients earlier, tailor treatments to individuals, and improve the design of clinical trials.
“With further refinement, these methodologies have the potential to predict symptom onset accurately enough for use in clinical care,” Petersen said.
Senior author Dr. Suzanne E. Schindler, associate professor of neurology at WashU, emphasized that the approach could revolutionize Alzheimer’s prevention. Since several new drugs may modestly slow disease progression if started early, knowing when symptoms will likely emerge could help doctors begin treatment well before memory decline sets in.
As research continues, the team hopes the test may soon be used in clinics, bringing the possibility of personalized, proactive Alzheimer’s care one step closer to reality.
🤔Nurses, will this impact your clinical practice? Share your thoughts about the study below.
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