The FDA cleared the first blood test intended to help in diagnosing Alzheimer’s, marking a significant step in making diagnosis more accessible and less invasive.
The test is designed for adults 55 and older who are showing signs or symptoms of cognitive decline, according to a May 16 news release from the agency. The test works by measuring two proteins in the blood, pTau217 and B-amyloid 1-42, and calculates a ratio that correlates with the presence or absence of amyloid plaques in the brain.
Detecting the amyloid plaques typically requires a PET scan or lumbar puncture to analyze cerebrospinal fluid.
The test’s clearance comes after the FDA reviewed clinical data from 499 individuals with cognitive impairment. The study showed that the blood test correctly identified the presence of amyloid plaques in 91.7% of cases and correctly ruled them out in 97.3% of negative cases.
The test is not approved as a screening tool for the general population and must be interpreted along with other clinical information, the release said.
