Predicting Amyloid Accumulation Using Peripheral Blood

A rapidly growing number of association studies across cohorts and continents are all pointing to the same conclusion: Plasma phospho-tau217 is an accurate biomarker for amyloid plaques, and even neurofibrillary tangles.

That’s the consensus emerging from the Clinical Trials on Alzheimer’s Disease conference, held last month. Several researchers, including ATRI's own Dr. Robert Rissman, concluded that the blood marker pegged plaque- or tangle-positive people with about 90 percent accuracy. Plasma p-tau217 also identified cognitively intact or impaired adults who were slipping fast on memory tests over six years. Given these findings, many scientists agreed that trialists may soon be able to forgo a PET scan in favor of a blood draw to screen for amyloid- and tau-positive participants.

At in 2022 at the Alzheimer’s Association International Conference, scientists honed in on plasma p-tau217 and the Aβ42/40 ratio as the leading markers of amyloid plaques in people with memory problems from community cohorts. This discussion continued at CTAD, where researchers agreed that p-tau217 also detects plaques, and even tangles and future cognitive decline, in cognitively normal older adults. 

Rissman has said, "It's taken a long time to get to a place where we can begin to reliably predict amyloid accumulation using peripheral blood. We still have a way to go to validate our data and understand the mechanisms of how tau species in blood relate to amyloid in the brain"

You can read more about Plasma P-tau217, and the BioMarker team's process and findings here on AlzForum.