By Chloe Elmer
Using a PET scan, researchers can detect amyloid buildup in the brain, but a Penn Memory Center study published in JAMA Neurology found that research participants can be frustrated with how their result is described, as either “elevated” or “not elevated” amyloid.
They want a number that explains how much amyloid, but such a number isn’t available. Study authors call for those describing these biomarkers to research participants to anticipate this need and explain why, at present, a personalized number isn’t available.
The study, known as the Study of Knowledge and Reactions to Amyloid Testing (SOKRATES), interviewed 50 participants in the A4 Study (Anti-Amyloid Treatment in Asymptomatic Alzheimer’s Study). The A4 Study is a clinical trial testing whether a drug (solanezumab) can slow decline seen in cognitively unimpaired older adults with elevated amyloid. A buildup of amyloid is common in the brains of older adults with Alzheimer’s disease dementia, but it can also be present in adults experiencing no loss in cognition. Memory problems might not surface for years, or even not at all.
The SOKRATES investigators found that A4 participants typically understood the terminology of “elevated amyloid” to mean “an increased, but uncertain, risk of developing AD.” They desired more information about how much is “elevated.” Some research participants were frustrated with their results, which they found difficult to interpret due to a lack of a scaling.
“Do I have 9 or 9,000 amyloids?” said one participant.
“They wanted a number,” said Dr. Jason Karlawish, Penn Memory Center co-director, “which is understandable as so much of medicine, especially geriatric medicine, is about risk and these dedicated participants are in the A4 Study in an effort to try to reduce their risk of developing dementia caused by Alzheimer’s disease.” Karlawish expanded on this issue in his latest Forbes column
But we simply can’t translate an individual’s amyloid result into this risk number, as we can with, for example, a bone mineral density. Amyloid isn’t ready for desktop medicine. The numbers just aren’t there. Yet.
“The reason there isn’t a number to give them is the science hasn’t discovered whether a number is a clinically accurate way to explain an amyloid scan and to treat the risk of developing dementia. A4 is among the studies that will contribute to this discovery.”
PMC researchers were also interested in how these results affected the participants’ daily life, behaviors, responsibilities, and relationships, and how the participants perceived their future — in addition to whom they disclosed their results and why.
“Clinicians and researchers need to understand how subjects comprehend this information, because knowing it may generate clinical and ethical problems, including the potential for misunderstanding, discrimination, stigma, depression, anxiety, and in the most extreme cases suicide in the face of a debilitating disease with no treatment,” the researchers wrote.
The study focused on telephone interviews with 50 participants from nine different sites who had PET results of “elevated amyloid.” The participants were all cognitively normal, unimpaired adults in the range of 65 to 85 years of age, and the interviews took place 4 to 12 weeks after the disclosure of their amyloid PET scan results. Subsequent reports will examine the 30 persons with the PET result of “not elevated” amyloid. Interviews were recorded, transcribed and coded for analysis. Sample questions included “What was the result of your amyloid PET scan?” followed by questions such as “Can you tell me in your own words what that means?” or “How would you explain it to a friend?”
In an editorial also published in JAMA Neurology, Winston Chiong, MD, PhD, called the findings “broadly reassuring regarding research participants’ ability to understand the prognostic uncertainty of amyloid imaging. But as the authors note, caution is needed in generalizing their results.”
Authors as listed: Jessica Mozersky PhD, Pamela Sankar PhD, Kristin Harkins MPH, Sara Hachey BSc, Jason Karlawish MD.