THURSDAY, Sept. 3, 2026 (HealthDay News) -- The U.S. Food and Drug Administration has cleared the PrecivityAD2 test for adults aged 40 years and older presenting with signs or symptoms of cognitive impairment and undergoing evaluation for Alzheimer disease or other forms of cognitive decline.PrecivityAD2 uses high-resolution mass spectrometry to provide quantitative measurements of protein biomarkers. The test is intended to be used in conjunction with a clinical assessment and is not intended as a screening or standalone diagnostic test.The clearance is based on a trial of 1,142 adults presenting with signs or symptoms of cognitive decline, which showed the test had comparable accuracy to cerebrospinal fluid tests and brain scans for detecting amyloid plaques across the spectrum of cognitive impairment. PrecivityAD2 showed a 97.6 percent positive predictive value (rule-in) for a positive result and a 93.1 percent negative predictive value (rule-out) for a negative result, based on established reference methods of amyloid positron emission tomography visual read or cerebrospinal fluid biomarker testing. Overall, a likely positive test result occurred in 17.3 percent of participants, with a positive predictive value of 77.3 percent."We believe the PrecivityAD2 test will play a vital health system role in the years ahead to help streamline and simplify the complex diagnostic pathway that many patients face when dealing with serious memory concerns," Joel Braunstein, M.D., cofounder, CEO, and president of C2N Diagnostics, said in a statement.Clearance of the PrecivityAD2 was granted to C2N Diagnostics.More Information.Sign up for our weekly HealthDay newsletter