14 Feb 2023

At last year’s CTAD conference, Oskar Hansson and Niklas Mattsson-Carlgren of Sweden’s Lund University reported that, among 171 cognitively intact older adults from the Swedish BioFINDER-1 and American WRAP cohorts who tested positive for amyloid plaques, those with the most phosphotau-217 in their blood declined the fastest on the modified Preclinical Alzheimer Cognitive Composite and Mini-Mental State Exam over six years (Dec 2022 conference news). On February 6, the research was published in JAMA Neurology.

First author Mattsson-Carlgren also determined the best combinations of blood biomarkers and demographics, including sex, APOE genotype, and years of education, to predict decline on the mPACC and MMSE. Plasma p-tau217, baseline mPACC scores, APOE4 status, and sex best foretold decline on the mPACC, while plasma p-tau217 and the cerebrospinal fluid Aβ42/40 ratio did so for the MMSE.

By itself, plasma p-tau217 was enough to flag those who would develop dementia. People with high plasma p-tau217 at baseline were twice as likely to progress to AD dementia within a decade as were those with low plasma p-tau217 (see image above).

The researchers calculated that adding plasma p-tau217 to clinical trial prescreening would slash sample size needed by 60 percent, offering a cheaper, minimally invasive way to find cognitively intact people most likely to decline.—Chelsea Weidman Burke