Neurology · General Practice · 2 h ago
Blood p-tau217 Levels Linked to Long-Term Cognitive Impairment Risk
A pooled analysis of six observational studies and clinical trials followed 2,684 cognitively unimpaired older adults across North America, Japan and Australia. Very high blood p-tau217 levels were associated with estimated cognitive impairment risks of 38% at five years and 78% at 10 years, although the longer-term estimate was less certain.
- Pooled analysis included 2,684 cognitively unimpaired older adults.
- Very high p-tau217 was linked to 38% five-year risk.
- The 10-year risk estimate was less certain.
- Researchers do not recommend routine screening of asymptomatic people.
Researchers combined data from six studies involving 2,684 older adults who had no cognitive impairment at enrollment. Participants had blood p-tau217 measurements and baseline amyloid PET scans, followed by annual assessments of memory, thinking and other cognitive abilities. The data included follow-up through 2025; approximately 478 participants developed cognitive impairment. The findings were published in JAMA and presented at the Alzheimer's Association International Conference.
Among participants with very high p-tau217 levels, the estimated probability of developing cognitive impairment was 38% within five years and 78% within 10 years. Higher p-tau217 was associated with future impairment after accounting for amyloid-beta plaques and genetic risk factors including APOE4. The 10-year estimate was based on substantially fewer observations and is less certain.
The researchers say the test may help identify candidates for prevention trials, but they do not recommend blood testing for routine risk screening in people without symptoms. Preventive disease-modifying treatments for this group have not been established. The cohorts may not represent the broader population, and the analysis estimates risk over limited periods rather than lifetime risk; larger, more representative studies are needed.
In practice
For cognitively unimpaired older adults, this pooled analysis suggests that very high blood p-tau217 levels can help stratify the likelihood of cognitive impairment over the next five years, with an estimated 38% risk in the highest group. The 10-year estimate of 78% is less certain because substantially fewer observations were available. The researchers do not recommend routine testing of asymptomatic people: preventive disease-modifying treatment has not been established for this population, and the cohorts may not represent the broader population. The findings may support prevention-trial recruitment, not a change in routine screening practice.
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JAMA (via ScienceDaily): A simple blood test could reveal Alzheimer’s risk 10 years before symptoms ↗This is an automated AI-condensed summary that has not yet been reviewed by an editor. Always consult the full item at the original source.