PrecivityAD is a blood test marketed to aid in the diagnosis of Alzheimer disease in patients 60 years or older with cognitive impairment. It is currently available in 47 states, the District of Columbia, and Puerto Rico. PrecivityAD is not approved by the U.S. Food and Drug Administration (FDA) but received breakthrough device designation from the FDA in 2019.

Using mass spectrometry, the PrecivityAD test quantifies the concentration ratio of two amyloid-beta (Abeta) peptides, Abeta 42 and 20, and detects apolipoprotein E (apoE) genotype. These markers help determine the diagnostic probability of Alzheimer disease.^1,2 These values, along with the patient's age, are used in a proprietary algorithm to provide an Amyloid Probability Score (APS). The APS is stratified as low (0 to 35) or high (58 to 100); a score of 36 to 57 is considered intermediate and requires further evaluation. A high APS indicates a higher likelihood that the patient will have amyloid plaques on amyloid positron emission tomography (PET).³