FRIDAY, July 17, 2026 (HealthDay News) -- Higher p-tau217 levels are associated with an increased risk for progression to cognitive impairment and accelerated cognitive decline among cognitively unimpaired older adults, according to a study published online July 14 in the Journal of the American Medical Association to coincide with the annual Alzheimer's Association International Conference, held from July 12 to 15 in London.
Rachel F. Buckley, Ph.D., from Mass General Brigham in Boston, and colleagues estimated the absolute risk for progression to cognitive impairment and rates of cognitive decline based on plasma p-tau217 across cognitively unimpaired older adults in a longitudinal cohort study using harmonized data from 2,684 adults across six observational and clinical trial cohorts.
The researchers found that during a median follow-up of 5.4 years, there were 478 events of progression to cognitive impairment. The risk for progression to cognitive impairment was increased in association with each one-standard deviation increase in baseline p-tau217 level (hazard ratio, 1.38); after adjustment, including β-amyloid positron emission tomography scan Centiloids, the association remained significant (hazard ratio, 1.32). An increased absolute risk for progression over five years was seen for participants with high and very high baseline p-tau217 (24 and 38 percent, respectively); over 10 years, risk was markedly higher, although limited data constrained longer-term estimates. There was also an association for elevated p-tau217 with faster cognitive decline based on change in the latent Preclinical Alzheimer Cognitive Composite score.
"Our findings provide some of the clearest evidence yet that elevated p-tau217 levels may help detect dementia risk years earlier -- even in adults with no noticeable memory or thinking problems," Buckley said in a statement. "Once verified, these blood tests could be used to recruit patients for clinical trials of treatments to prevent cognitive decline and dementia. In the future, when treatments are approved for use early in the disease process, these tests could help guide monitoring, treatment decisions, and counseling for patients and families."
Several authors disclosed ties to the biopharmaceutical industry.
