A recent study by Sebastian Palmqvist of Lund University in Sweden has sparked excitement over the potential of a blood test to diagnose Alzheimer’s disease. The study, published in the Journal of the American Medical Association (JAMA), found that the blood test, called PrecivityAD2, was highly accurate in diagnosing Alzheimer’s among patients in the study. However, the test is limited in its practical benefits due to the controversial nature of potential treatments for Alzheimer’s and its narrow window of value in the progression of the disease.
These blood tests, like all tests for Alzheimer’s disease, do not show the disease itself but rather identify biomarkers linked to Alzheimer’s, such as amyloid beta (AB) and tau proteins. The purpose of these tests is to determine if cognitive impairment is caused by Alzheimer’s or another condition resulting in memory loss. The biomarker blood test was found to be more accurate in diagnosing Alzheimer’s compared to other diagnostic methods such as PET scans, lumbar punctures, and cognitive testing, which are less invasive and costly but have their own limitations.
While a blood test for Alzheimer’s could benefit a limited number of patients by providing an early diagnosis and prompting lifestyle changes and planning for the future, it may also increase anxiety without providing any clinical benefit. Biomarker testing may have limited value for those experiencing increased memory problems without a clinical diagnosis. Therefore, it is important to consider that occasional memory lapses do not necessarily warrant an Alzheimer’s blood test, and the tests may not be useful for patients with advanced disease beyond the benefits of current treatments.
The study highlights the importance of understanding how these biomarkers will impact patient care and treatment decisions. The newly-approved monoclonal antibody drugs, such as Leqembi, which clear AB and tau proteins from the brain, have limited effectiveness in slowing the progression of Alzheimer’s disease and come with high costs and dangerous side effects. This has led to debate among neurologists over whether to prescribe these drugs, as they may not provide any benefit for those with advanced disease.
Overall, while biomarker blood tests for Alzheimer’s represent an important advancement for researchers in understanding the disease, their practical benefits for real-world patients may be more modest than initially anticipated. More research is needed to determine the impact of these tests on patient care and treatment decisions, as well as how they can be effectively integrated into clinical practice to improve outcomes for individuals with Alzheimer’s disease.
