APOE variant may help p-tau217 levels predict who develops cognitive decline sooner

• Higher blood p-tau217 levels were associated with a greater risk of cognitive impairment, with the association stronger among APOE-ε4 carriers, suggesting that genetic background may influence p-tau217’s predictive power for cognitive decline.
• APOE-ε4 carriers with higher p-tau217 levels also developed cognitive impairment sooner, with each standard deviation increase in p-tau217 associated with a 24% shorter time to impairment.
• Combining p-tau217 with APOE genotype could improve risk stratification, potentially helping identify people who may benefit from closer monitoring.
• However, further research is necessary to validate the approach across diverse populations.

P-tau217 is a form of phosphorylated tau that can be measured in the blood. It is considered an important biomarker of the biological changes associated with Alzheimer’s disease.

Levels of p-tau217 can rise during the early stages of Alzheimer’s-related pathology, potentially before noticeable symptoms develop. However, individuals with a similar p-tau217 biomarker level may experience different clinical trajectories.

The apolipoprotein E (APOE) gene is involved in lipid transport and brain health, and the APOE-ε4 variant is an established genetic risk factor for Alzheimer’s disease compared with people who do not carry it.

Now, new research suggests that while higher levels of p-tau217 may signal a greater risk of cognitive impairment, a person’s genetic background could help determine how quickly that impairment develops.

The findings, published in The Lancet Neurology, suggest that APOE-ε4 status may provide information about the timing of cognitive decline.

The results suggest that combining p-tau217 measurements with APOE genotype could eventually help researchers better identify people at higher risk of cognitive decline and determine who may benefit from closer monitoring.