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With the recent approval of two new treatments for Alzheimer’s disease, there is renewed hope for individuals at risk of this debilitating condition. However, the ability to detect the disease at an early stage lags behind. Early diagnosis is crucial as it allows individuals to benefit from medications when they are most effective.
Currently, detecting Alzheimer’s is challenging. Although brain scans like PET can identify amyloid plaques, the protein clusters characteristic of the disease, by the time these plaques are detected, brain function has already started to decline. Additionally, these scans are costly and not widely available at all medical facilities. While analyzing spinal fluid can provide a more sensitive way to detect amyloid and tau proteins associated with the disease, it requires a painful and potentially risky spinal tap. Although blood tests for these proteins have not yet been approved by the FDA, they have received breakthrough designation for expedited review upon completion of studies.
In a recent study published in Nature Medicine, researchers from Washington University in St. Louis unveiled a promising blood test they developed to identify a distinct form of tau protein, which they believe is a more accurate indicator of the protein’s accumulation in the brain and correlates with the disease’s severity. Comparing the blood test results to brain scans, the team found that the blood test was 92% accurate in detecting tau.
Dr. Randall Bateman, a neurology professor at Washington University and the study’s senior author, emphasizes that the presence of both amyloid and tau proteins is crucial for diagnosing Alzheimer’s disease. While amyloid plaques take years to form and trigger symptoms like memory loss, confusion, and disorientation, the abnormal development of tau inside and outside brain neurons marks the progression of the disease.
Bateman explains that the crystalized form of tau is strongly linked to cognitive decline in Alzheimer’s patients. Detecting this form of tau early on could help identify individuals at risk of developing more severe memory and cognitive issues. The team initially developed a test for this form of tau in spinal fluid but shifted focus to a blood test due to the inconvenience and risks associated with spinal taps.
This groundbreaking discovery marks the first identification of a blood marker for tau tangles, paving the way for improved diagnosis and treatment of Alzheimer’s disease.
Detecting crystalized tau in the blood was a challenging task, but after thorough examination of various blood markers, researchers were able to pinpoint it. They meticulously analyzed the structure of different forms of tau until they identified the specific form associated with tangles. This discovery led to the establishment of C2N Diagnostics by Bateman, with the aim of producing and distributing the test for use in clinical trials. This blood-based test has the potential to expedite the development of anti-tau therapies for Alzheimer’s by enabling drug developers to quickly assess the impact of their compounds on tau levels in the brain using a simple blood sample. The ability to monitor tau levels easily could offer valuable insights into the progression of Alzheimer’s and open up new avenues for drug targeting. While the relationship between phosphorylated tau outside neurons and crystalized tau within cells remains unclear, it is speculated that the accumulation of phosphorylated tau may trigger the formation of harmful crystalized tau inside neurons. Furthermore, the mechanism by which crystalized tau fragments escape from nerve cells remains a mystery. Understanding these processes could pave the way for novel approaches to managing tau and potentially slowing down the advancement of the disease. Bateman emphasizes the importance of comprehending the root causes of Alzheimer’s to develop more effective treatments for patients. For further inquiries, please contact us at letters@time.com.
