New advancements in blood testing could revolutionize the way doctors diagnose Alzheimer’s disease, potentially making the process faster and more precise, according to recent findings presented on Sunday. However, some tests appear to be significantly more effective than others.
Diagnosing Alzheimer’s can be challenging since confirming it typically requires detecting beta-amyloid protein buildup, a hallmark of the disease, through invasive brain scans or spinal taps. Many patients are diagnosed based on symptoms and cognitive evaluations instead.
Recently, blood tests that identify specific indicators of Alzheimer’s have become available. Although these tests show promise, they are not yet widely adopted due to the lack of comprehensive data guiding their use. Additionally, the U.S. Food and Drug Administration has not approved any of these tests, and insurance coverage is sparse. Alzheimer’s affects over 6 million people in the U.S. alone, with many more worldwide.
The disease is characterized by amyloid plaques and tau protein tangles in the brain, which damage neurons. New medications like Leqembi and Kisunla can slow symptom progression by targeting amyloid, but they are effective only in the earliest stages of the disease, and proving eligibility can be challenging. Spinal fluid tests are invasive, and specialized PET scans are expensive and may have long wait times.
Even specialists can struggle to determine whether Alzheimer’s is causing a patient’s symptoms. Blood tests have mostly been used in controlled research settings, but a new study involving around 1,200 Swedish patients suggests they can be effective in real-world medical environments, including primary care settings.
This study found that while initial diagnoses by primary care doctors and specialists were 61% and 73% accurate respectively, blood tests achieved a 91% accuracy rate, as reported at the Alzheimer’s Association International Conference in Philadelphia and published in the Journal of the American Medical Association.
Dr. John Hsiao of the National Institute on Aging highlighted the current variability in blood tests, noting the need for those with proven accuracy rates exceeding 90%. The p-tau217 tests are currently the most reliable, according to Alzheimer’s Association chief science officer Maria Carrillo and other experts. This type of test measures tau protein levels that correlate with plaque buildup, helping determine the likelihood of Alzheimer’s.
Several companies, including ALZpath Inc., Roche, Eli Lilly, and C2N Diagnostics, are developing p-tau217 tests. These tests are available only through medical professionals and are expected to be clarified further with upcoming FDA approvals. Until then, doctors are advised to use blood tests only for individuals with memory issues, ensuring they are aware of the test’s accuracy.
For primary care physicians, these tests offer significant potential to differentiate between those who need further evaluation and those who do not, said Dr. Sebastian Palmqvist of Lund University. However, these tests are not recommended for individuals without symptoms, unless part of a research study, as amyloid buildup can precede memory problems by up to 20 years.
As reported by apnews.com, while there are no preventive measures beyond general health advice, ongoing research is exploring possible therapies for high-risk individuals, some of which include blood testing.