Soon, doctors may be able to diagnose Alzheimer's using just a simple blood test

Researchers are making strides toward simplifying the diagnosis of Alzheimer’s disease, a process historically fraught with challenges and delays. In the coming years, one or more blood tests could revolutionize Alzheimer’s diagnosis, offering a more accessible and efficient approach for patients. While several blood tests for Alzheimer’s are already in use in research settings, they have not yet become standard practice for doctors in most countries. To address this gap, a coalition of UK medical research funders has initiated a project aimed at determining the most effective blood test for real-world diagnostic use. The project’s goal is to have at least one blood test ready for routine use when individuals consult a doctor for memory-related concerns within the next five years. Susan Kohlhaas of Alzheimer’s Research UK expressed optimism about the transformative potential of this project, stating, “We expect, in the next five years, the pathway to somebody getting a diagnosis to be completely different.” The confidence in the project’s success is based on the proven accuracy of these blood tests in research. Joanne Rodda of the Kent and Medway Medical School in Canterbury, UK, noted that these tests exhibit accuracy comparable to spinal fluid tests, which are currently part of the Alzheimer’s diagnosis process. The blood tests used in research typically focus on two proteins associated with Alzheimer’s disease: beta-amyloid, which accumulates outside brain cells, and tau, which accumulates within the cells. Various companies worldwide offer testing for these Alzheimer’s-related proteins to assess the presence of the condition. The need for real-world assessment arises from the fact that clinical trials involving Alzheimer’s patients often predominantly include individuals who are white and have higher income levels, which may not represent the broader population affected by the disease. Additionally, factors like diet and lifestyle can influence test results. The Blood Biomarker Challenge, a project jointly conducted by the Alzheimer’s Society, Alzheimer’s Research UK, and the UK’s National Institute for Health and Care Research, seeks to compare different available blood tests and determine their practicality for diagnosing Alzheimer’s. The urgency for such advancements partially arises from the development of treatments designed to clear amyloid from the brain. Two drugs that target amyloid, lecanemab being one of them, have shown some promise in slowing the progression of Alzheimer’s. However, these drugs require confirmation of amyloid buildup, often obtained through invasive procedures. A reliable blood test for amyloid could streamline the process. Even before new treatments become widely available, a blood test could expedite the diagnostic journey for individuals experiencing memory issues. Currently, obtaining an Alzheimer’s diagnosis can be a lengthy and multifaceted process, involving cognitive tests and brain scans. A blood test would complement these assessments rather than replace them. While the prospect of blood tests for Alzheimer’s is promising, it’s crucial to emphasize that these tests should be administered within a clinical context and under a doctor’s guidance. As Rob Howard at University College London points out, while consumer tests are available online in the US, they should not substitute a comprehensive clinical assessment. Proper diagnosis and treatment decisions should always involve medical professionals.