Overview
- Mass General Brigham researchers report in a Nature Communications paper published Tuesday that a plasma pTau217 blood test forecasted Alzheimer’s‑related changes in 317 cognitively healthy adults tracked in the Harvard Aging Brain Study.
- Higher baseline pTau217 levels predicted faster buildup of brain amyloid and tau and greater future cognitive decline even when initial amyloid PET scans looked normal.
- The team measured a mass‑spectrometry %pTau217 score and found a clear link, with each 1‑percentage‑point higher baseline value tied to about 0.35 centiloid units more amyloid per year on PET scans.
- Very low pTau217 levels signaled a low near‑term chance of turning amyloid‑positive, pointing to a practical way to sort who may need closer follow‑up or be a fit for prevention trials.
- The findings support trial screening and early risk stratification, and they arrive as the FDA’s 2025‑cleared blood tests remain limited to symptomatic patients and as a new survey shows most primary‑care patients would accept testing but worry about cost and accuracy.