Blood test can help identify people at high risk for Alzheimer's, study shows

Key Points:

• Researchers have identified a blood test measuring p-tau217 that may predict the likelihood of apparently healthy older adults developing Alzheimer’s symptoms within five to 10 years, potentially aiding early identification for clinical trials and future treatments.
• The study found that individuals with very high p-tau217 levels had a 38% risk of cognitive impairment over five years, increasing to 78% over 10 years, while those with low levels had a correspondingly low risk.
• Experts caution that the test is not yet precise enough for individual prognoses and recommend against healthy people seeking the test until effective preventive treatments become available.
• The findings, published in JAMA and presented at the Alzheimer’s Association International Conference, support the theory that amyloid plaques trigger tau tangles, with p-tau217 serving as a biomarker indicating progression toward Alzheimer’s.
• While promising, limitations include a smaller sample size for the 10-year risk estimate and potential confounding factors such as vascular dementia; ongoing research is needed to validate the test’s clinical utility.