There’s new progress in the battle against Alzheimer’s disease.
About 1 in 9 US seniors has Alzheimer’s, the most common form of dementia, which slowly impairs memory, thinking skills and the ability to perform even basic tasks.
There is no single, easy test to diagnose Alzheimer’s, but a new review of 18 scientific studies confirms that a simple blood test can detect early signs of the brain disorder before cognitive symptoms appear.
The protein p-tau217 has become a reliable Alzheimer’s biomarker because its concentration in the blood is strongly linked to the presence of amyloid plaques and tau tangles in the brain, two hallmarks of Alzheimer’s.
The research out this week in JAMA Neurology supports the use of p-tau217 blood tests as a “minimally invasive tool” for early identification of Alzheimer’s, “particularly in settings where timely intervention with disease-modifying therapies may offer the greatest benefit in slowing or preventing disease progression.”
Dr. Liron Sinvani, director of the Geriatric Hospitalist Service at Northwell Health and director of research for hospital medicine, called the finding “a major breakthrough.”
“Just a simple blood test to see if this protein, this p-tau217, is present can indicate that someone is at a very high risk of having dementia right before symptoms even start,” said Sinvani, who was not involved in the new research.
“This is definitely a big finding in terms of, ‘OK. Can we identify people before they even have symptoms of dementia?’”
Dementia symptoms can include memory loss, difficulties with familiar tasks, communication troubles, disorientation, poor judgment and mood or personality changes.
An assessment of symptoms is used to diagnose Alzheimer’s, along with a review of health history and physical and neurological exams. Brain imaging and a spinal fluid analysis can help confirm the diagnosis and rule out other conditions.
Blood tests are an up-and-coming method for identifying Alzheimer’s, with the US Food and Drug Administration recently approving new blood testing for people 55 and older experiencing symptoms like memory loss.
P-tau217 blood tests typically require a doctor’s order, though one sells online for $229 with the promise that “no doctor or insurance is needed.”
The new JAMA review, which included data from over 7,800 people, found that p-tau217 levels were much higher in amyloid-positive people than in amyloid-negative people, even though these individuals had no cognitive symptoms.
Amyloid plaques are clumps of misfolded proteins in the brain that can disrupt brain function.
It’s a tell-tale sign of Alzheimer’s.
The problem is that there’s no cure for amyloid plaques in the brain, though there are treatments that can reduce them in the early stages of Alzheimer’s.
“The question in my mind is, at this moment, how many people would want to know that they have this biomarker and have a high risk of dementia?” Sinvani mused.
“The reason why this isn’t ready for primetime is because we don’t have medications right now that would be offered,” she continued, “but the goal is that if we can identify people early enough, before they even start having symptoms, then we can potentially, hopefully as medications develop, be able to introduce medications that can prevent or slow down the progression.”
While there is no cure for Alzheimer’s, lifestyle changes can lower the risk or potentially slow progression.
“A healthy diet, exercise, increased socialization, making connections and keeping your brain active,” Sinvani said, “these are all things that can impact the trajectory of dementia, and so, knowing that you are at very high risk could be a nice way to sort of incentivize people to start doing something about it.”
