A new blood test may revolutionize the way doctors diagnose Alzheimer’s disease and track its progress. This test could make it easier to identify the disease in patients with memory problems and determine how advanced it is. The breakthrough offers hope for better treatment, especially with new drugs like donanemab and lecanemab. These medications are most effective in the early stages of the disease, making early detection critical.

Professor Oskar Hansson from Lund University, who co-authored the study, highlighted the growing need for reliable and affordable Alzheimer’s tests. As more countries approve treatments that target amyloid buildup in the brain, having a simple test could help doctors identify patients who would benefit from these drugs.

Key Alzheimer’s Marker Found in Blood

Alzheimer’s disease is mainly caused by the buildup of two harmful proteins: amyloid plaques and tau tangles. The study, published in Nature Medicine, focused on a specific fragment of tau protein called eMTBR-tau243. Researchers discovered this fragment in blood samples and linked it to the presence of tau tangles, a major feature of Alzheimer’s.

The study examined 902 people, some with mild cognitive issues and others with full dementia. Those with Alzheimer’s had higher levels of eMTBR-tau243 in their blood, and levels increased as the disease worsened. In contrast, people with memory problems caused by other conditions did not show high levels of this protein. This suggests that eMTBR-tau243 is a strong indicator of Alzheimer’s.

Professor Tara Spires-Jones from the University of Edinburgh, who was not involved in the research, called the results promising. She explained that this blood marker performed better than many existing tests. However, she cautioned that the test is not yet ready for widespread use. The process to detect this marker is still complex and expensive, so researchers need to develop a simpler and more affordable method.

A New Era of Personalized Alzheimer’s Care

Dr. Sheona Scales from Alzheimer’s Research UK emphasized the importance of this discovery. She noted that while several biomarkers are under study, eMTBR-tau243 is particularly promising. Its strong link to memory and thinking ability could help doctors track how the disease affects the brain over time.

In a separate Nature Medicine study, researchers identified two other proteins—YWHAG and NPTX2—found in cerebrospinal fluid. These proteins seem to reflect cognitive decline, regardless of amyloid or tau levels. The study analyzed 3,397 samples from people in the US, Sweden, and Finland. Scientists found that the ratio of these proteins provided a reliable way to measure mental decline in Alzheimer’s patients.

Professor Tony Wyss-Coray from Stanford University, a co-author of the second study, said these findings could help improve treatments. By identifying the right patients, doctors can match them with the best therapies. This discovery could also make clinical trials more effective by selecting participants based on how the disease is progressing in their brains.

Bringing Alzheimer’s Testing to the Public

While these findings mark a major step forward, experts stress that more work is needed before blood tests become part of routine Alzheimer’s care. Right now, diagnosing the disease often requires expensive brain scans or spinal fluid tests, which are not widely available. A simple blood test would make detection easier and more affordable.

Some pharmaceutical companies are already working on bringing Alzheimer’s blood tests to the market. For example, C2N Diagnostics has developed a test that measures amyloid levels in the blood. Other companies, like Roche and Quanterix, are also developing similar tools. If these tests become widely available, they could help millions of people get diagnosed earlier and receive treatment sooner.

The Future of Alzheimer’s Treatment

These studies offer new hope for Alzheimer’s patients and their families. With better testing methods, doctors can identify the disease sooner and monitor how it progresses. This is especially important as new treatments emerge that can slow memory decline if given early enough.

Experts agree that early diagnosis is key to fighting Alzheimer’s. The sooner doctors detect the disease, the better they can manage symptoms and improve patients’ quality of life. With continued research, the dream of a simple, affordable blood test for Alzheimer’s may soon become a reality.