New blood test to detect Alzheimer's before it starts

A new blood test has been approved in Switzerland for the early detection of Alzheimer’s disease, offering a potential breakthrough in diagnosing the condition before memory loss becomes severe. Two tests based on specific biomarkers have recently received European CE certification and can now be used in clinical practice, including in Switzerland. These tests analyze levels of a protein called pTau217, which is linked to abnormal protein deposits in the brain characteristic of Alzheimer’s. The approval marks a significant shift in how the disease is diagnosed, potentially making the process more accessible and less burdensome for patients. The current diagnostic process for Alzheimer’s involves a combination of clinical assessments, cognitive testing, and more invasive procedures such as lumbar punctures or positron emission tomography scans. In Switzerland, approximately 100,000 people live with Alzheimer’s, though only about half have received a formal diagnosis. These methods are often time-consuming, costly, and require specialized facilities, limiting access for many individuals. The new blood tests aim to simplify this process by providing a non-invasive alternative that could identify early signs of the disease. Both newly certified tests rely on measuring pTau217, a variant of the tau protein associated with the formation of amyloid plaques in the brain, hallmarks of Alzheimer’s pathology. While the results of these tests provide valuable information, they are not definitive diagnoses. As Dr. Julius Popp, a specialist in dementia care at the Hirslanden Center for Memory Disorders in Zurich, explains, “A biomarker result is not a diagnosis, but rather one piece of a larger picture.” Nevertheless, he emphasizes that the tests represent a major advancement in diagnostic capabilities, promising greater efficiency and accuracy in identifying Alzheimer’s in its early stages. Dr. Popp has already begun using the blood test in his clinic and is actively involved in developing national guidelines through the Swiss Memory Clinics organization. He stresses that the test should only be used in cases where individuals exhibit symptoms consistent with Alzheimer’s. It is not intended as a preventive measure, nor should it be used simply because the disease runs in a family. Instead, it is designed to support clinicians in confirming a suspected diagnosis. Valerie Bösch, a scientific staff member at the Alzheimer Society of Switzerland, supports the introduction of the test but highlights the need for proper training and guidance for general practitioners. She notes that while the test can be conducted in primary care settings, healthcare providers must be equipped to interpret the results accurately. “It is not meant to be used as a routine screening tool,” she says. “Patients must show certain symptoms before undergoing the test.” Early signs of Alzheimer’s are often subtle and can be mistaken for normal age-related changes. Common initial indicators include difficulty recalling recent events, forgetting appointments or conversations, and trouble completing familiar tasks. As the disease progresses, symptoms become more pronounced, affecting daily functioning and requiring more intensive medical intervention. Early detection remains crucial, as interventions may be more effective in slowing the progression of the disease when initiated sooner. With the availability of these new tests, there is hope that more people will receive timely diagnoses, enabling earlier intervention and better management of the condition. However, ongoing efforts will be necessary to ensure that healthcare professionals are adequately trained to use these tools effectively and that patients understand their limitations and appropriate applications. The future of Alzheimer’s diagnosis may soon look very different, thanks to these groundbreaking developments.