Scientists have developed a promising blood test that can determine the progression of Alzheimer’s disease. Published in the journal Nature Medicine, this research was conducted by experts at Washington University in St. Louis and Lund University in Sweden. Identifying the stage of dementia is crucial for providing patients with the most effective treatments.
This new test doesn’t just diagnose Alzheimer’s; it can also discern if another condition is causing symptoms. Researchers examined blood samples from 163 individuals with varying degrees of cognitive decline. They discovered that a protein called MTBR-tau243 is linked to the amount of tau protein in the brain, with an impressive 92% accuracy when compared to brain scans.
The more tau accumulates, the more severe the Alzheimer’s symptoms become. Those without symptoms showed normal levels of MTBR-tau243, suggesting that high levels of this protein are associated with advanced stages of the disease. Interestingly, normal levels were also found in individuals whose dementia symptoms were caused by conditions other than Alzheimer’s.
Tau proteins form tangles in the brains of people with Alzheimer’s, disrupting cognitive functions. These tangles typically appear years after amyloid plaques form, which are initial indicators of the disease. The research noted that tau levels were 200 times higher in those with advanced dementia stages.
Currently, positron emission tomography (PET) brain scans are the standard for staging Alzheimer’s, but they have some limitations. According to Courtney Kloske, Ph.D., from the Alzheimer’s Association, amyloid plaques and tau tangles define the brain changes in Alzheimer’s, which lead to memory and thinking issues. While blood tests for amyloid are available, this is the first to measure tau levels.
The study suggests that blood tests for both amyloid and tau could confirm Alzheimer’s as the cause of dementia, providing a clearer diagnosis and treatment path. “This blood test clearly identifies Alzheimer’s tau tangles, which is our best biomarker measure of Alzheimer’s symptoms and dementia,” said Randall J. Bateman, MD, from WashU Medicine.
Dr. Daniel Lesley, a neurologist at Remo Health, believes following tau proteins can assess treatment effectiveness. He noted that while the correlation isn’t perfect for real-world use, it’s a promising direction for research. PET scans, although useful, are costly and not widely available, which limits their accessibility.
Kanta Horie, Ph.D., from WashU Medicine, highlights the potential of personalized medicine for Alzheimer’s. With early stages showing low tau tangles, anti-amyloid therapies might be more effective. In contrast, advanced stages with high tau tangles might benefit more from anti-tau therapies.
The study emphasizes the need for further research to validate these findings in larger populations. The research was supported by various institutions including the National Institutes of Health and the Alzheimer’s Association. This advancement in blood testing could revolutionize how we diagnose and treat Alzheimer’s, offering hope for more tailored and effective interventions.
