The Food and Drug Administration (FDA) has cleared a new blood test designed to help diagnose Alzheimer's disease, which is expected to be available later this year. The blood test, known as PrecivityAD2, was developed by C2N Diagnostics and was manufactured for use in adults aged 40 years and older who present with the signs or symptoms of cognitive impairment, while undergoing assessment for Alzheimer's disease. The test would be used in conjunction with clinical evaluation to assist health care professionals in identifying patients with the disease, so is therefore not intended to be a standalone test or a screening tool.
It is the first test the FDA has cleared for use in symptomatic adults aged 40 and over, according to C2N Diagnostics. Newsweek has contacted the FDA and C2N Diagnostics outside of regular working hours via email for comment. Alzheimer's is the most common type of dementia, accounting for 60 to 80 percent of cases, according to the Alzheimer's Association.
It is estimated that today around 7.4 million Americans aged 65 and older live with Alzheimer's disease, with forecasts suggesting that number could rise to 13.8 million by 2060. Alzheimer's is a progressive disease, and patients on average live between four to eight years following the diagnosis, although some may live on for as long as 20 years. A 2026 study published in the journal Alzheimer's & Dementia indicated that reported deaths from Alzheimer's disease increased by 134 percent between 2000 to 2024.
The build-up of two proteins in the brain—beta-amyloid and tau—are believed to be the prime suspects that damage nerve cells and lead to the development of Alzheimer's disease. The destruction of nerve cells due to the accumulation of these proteins is what leads to memory failure, personality changes, problems carrying out daily activities and other symptoms associated with the disease. In order to diagnose Alzheimer's disease, a healthcare professional will review a patient's symptoms, and often speak to family members as well.
Early symptoms include memory loss, trouble with concentration, poor judgment in decision-making, changes in mood, trouble with communication, confusion and many others. Based on an evaluation of the signs and severity of associated symptoms, a clinician may then decide to arrange various laboratory tests and brain imaging scans for the patient. C2N Diagnostics' blood test is designed to detect brain amyloid plaques to help further support and inform a clinical assessment.
These plaques are the build up of the beta-amyloid protein associated with Alzheimer's disease. In a clinical validation study of more than 1,000 participants, the test demonstrated a 97.6 percent positive predictive value for a positive result, and a 93.1 percent negative predictive value for a negative result. C2N Diagnostics said that its test was therefore "effective" at detecting amyloid plaques across a spectrum of cognitive impairment, including subjects with mild symptoms and those with more advanced cognitive concerns.
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