The FDA cleared the first blood test to aid Alzheimer's diagnosis. The Lumipulse G p Tau217/ß-Amyloid 1-42 Plasma Ratio from Fujirebio Diagnostics detects amyloid plaques in adults 55+ with cognitive symptoms.

The test measures p Tau217 and β-amyloid 1-42 proteins in plasma, calculating a ratio correlated to brain amyloid plaques. This less invasive option reduces reliance on costly PET scans and spinal taps. Commissioner Martin A. Makary noted 10% of people 65+ have Alzheimer's, doubling by 2050.

In a 499-sample study, 91.7% of positive results matched amyloid presence via PET or CSF, and 97.3% of negatives matched negative scans. CDRH Director Michelle Tarver highlighted nearly 7 million Americans live with Alzheimer's, rising to 13 million.

The test received Breakthrough Device designation and 510(k) clearance. It's not a standalone screen; results require clinical correlation. Risks include false positives/negatives leading to misdiagnosis or delayed treatment.