A new blood test can accurately diagnose Alzheimer’s disease in individuals with memory issues 91% of the time, significantly outperforming traditional diagnostic methods.
These findings were published on July 28 in the journal JAMA and presented at the Alzheimer’s Association International Conference, marking a significant advancement in developing a simpler, cheaper diagnostic tool for Alzheimer’s, which affects nearly 7 million Americans.
“This breakthrough could significantly impact individuals seeking help for memory loss and suspected Alzheimer’s,” said Dr. Oskar Hansson, professor of neurology at Lund University in Sweden and one of the study’s authors.
Detecting Alzheimer’s Through a Blood Test
The study involved 1,213 Swedish participants, averaging 74 years old, who were experiencing mild memory symptoms—a potential early indicator of Alzheimer’s. The participants were divided into two groups: 515 were evaluated in primary care and 698 in specialist memory clinics. They underwent the new blood test, and the results were confirmed with cerebrospinal fluid tests.
Researchers measured the levels of plasma phosphorylated tau 217 (p-tau217) and amyloid beta, proteins associated with Alzheimer’s. The blood test’s accuracy in identifying Alzheimer’s was around 90%, compared to 61% for primary care doctors and 73% for specialists.
The test’s simplicity and reliability represent a significant advancement, offering a straightforward method to diagnose Alzheimer’s in primary care, reducing the need for invasive tests and extensive screenings. This could lead to quicker, easier diagnoses, allowing patients to plan and prepare for their future more effectively.
Cautions and Future Steps
The study was conducted in Sweden, and researchers emphasize the need for confirmation in a diverse American population. Additionally, the test should be used only for individuals already showing symptoms of cognitive decline, not as a predictive tool for healthy individuals.
“The next steps include establishing clear clinical guidelines for the blood test’s use in healthcare,” Hansson said. “The test is already available in the USA and is likely to become available in many other countries soon. Initially, it will mainly be used in specialist memory clinics, and it may take approximately one to two years to implement guidelines and training in primary care.”
Current Methods to Diagnose Alzheimer’s
Currently, Alzheimer’s diagnosis involves a combination of medical history, medication review, family and social history, comprehensive neurological exams, neuropsychological testing, and brain imaging techniques like MRI scans. Advanced imaging, such as PET scans or spinal fluid tests, may also be used but are more invasive and complex.
“The new blood test is promising but not yet a replacement for the current comprehensive diagnostic process,” said Dr. Joel Salinas, Clinical Assistant Professor of Neurology at NYU Grossman School of Medicine. “It is less invasive and more accessible than spinal fluid tests and can guide who would benefit most from advanced imaging studies.”
The test is most accurate in patients with progressed dementia or mild cognitive impairment and less so in early stages of cognitive decline. Further research is needed to establish guidelines for its use and its role in improving treatment outcomes.
Implications for the Future
Alzheimer’s affects one in five women and one in ten men over their lifetimes, with symptoms often going undetected for up to 20 years. Routine screening and more research are essential for early detection.
“The next step is creating a pipeline for quick access to diagnosis and management of amnestic mild cognitive impairment and mild Alzheimer’s dementia,” said Dr. Kaitlin Seibert, assistant professor of neurology at University of Chicago Medicine. “Clinician assessment is integral to identify the right patients for further testing.”
Currently, the test is available for use by doctors, not directly to consumers. “Individuals interested in this blood test should discuss it with their healthcare provider, who can determine if it is appropriate based on their symptoms and medical history,” Salinas said. “As research progresses and guidelines are established, it may become more widely available and integrated into standard diagnostic practices.”
Early diagnosis is crucial for planning and managing Alzheimer’s, significantly impacting long-term health and quality of life. Dr. Seibert emphasizes the importance of seeking care for memory changes and the role of loved ones in early diagnosis and management.
“Close and caring attention from friends, family members, and close contacts is critically important in early diagnosis and management of Alzheimer’s disease,” Seibert added.
