Health Capsule

A recent study has found that a simple blood test may help predict when a person will begin to experience symptoms of Alzheimer’s disease. This discovery could support scientists in developing more effective strategies to delay or reduce the impact of the condition.

Alzheimer’s disease is a progressive disorder of the brain that gradually damages memory and thinking abilities. It is the leading cause of dementia worldwide. While there is currently no cure, certain treatments can help manage symptoms.

People diagnosed with Alzheimer’s tend to have elevated levels of a protein known as p-tau217 in their bloodstream. In the study, researchers analyzed information from 603 individuals who underwent repeated p-tau217 blood testing over a period of time. Using these results, they designed a predictive “clock” model.

This model was able to pinpoint individuals at higher risk of developing Alzheimer’s symptoms. For participants who eventually showed symptoms, it also estimated the likely age at which those symptoms would begin. Researchers found that the interval between the first elevated test result and the onset of symptoms became shorter with increasing age. For example, someone with high p-tau217 levels at age 60 might develop symptoms roughly 20 years later. In contrast, a person with similarly high levels at age 80 might begin showing symptoms in about 11 years.

The results indicate that a single blood test could potentially help estimate how much time remains before Alzheimer’s symptoms appear. However, experts caution that additional studies are necessary before this approach can be introduced into clinical practice. Work is ongoing to refine and strengthen the accuracy of the model.

“Our long-term aim is to predict when a person is most likely to develop symptoms,” explains Dr. Suzanne Schindler of Washington University in St. Louis. “This would allow patients and their physicians to plan ahead and consider strategies to prevent or slow the progression of the disease.”