Blood test could predict Alzheimer's cognitive decline years early, international study finds
p-tau217 linked to estimated 38% five-year and 78% 10-year impairment risk among people with very high levels, though the longer-term estimate is less certain; routine screening is not recommended
A large international study found that a simple blood test measuring p-tau217 could help estimate a person's risk of developing Alzheimer's-related cognitive decline years before symptoms appear. Among older adults with no signs of cognitive impairment, those with very high levels of the biomarker had an estimated 38% chance of impairment within five years and an estimated 78% chance within 10 years, with the longer-term estimate less certain. The findings were published in JAMA and presented at the Alzheimer's Association International Conference.