The FDA cleared C2N Diagnostics' PrecivityAD2 on Aug. 20, 2026 for adults 40 and older with signs or symptoms of cognitive impairment.
For memory clinic patients, that clearance offers earlier blood-based amyloid insight to speed workup, guide confirmation testing, and inform treatment and trial choices. PrecivityAD2 is a blood test that estimates the likelihood of brain amyloid pathology, a hallmark change linked to Alzheimer's disease. It does not replace a clinical exam, and it is not meant for people without symptoms.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Official resources:
- Read the official guidance from C2N — Use this primary source to verify the official guidance.
- Read the official guidance from Alz — Use this primary source to verify the official guidance.
Table of Contents
- How does the test estimate amyloid risk?
- How accurate is it in symptomatic adults?
- Who qualifies, and who should not seek it?
- What changes at a memory clinic visit?
- When and where is the cleared test available?
How does the test estimate amyloid risk?
The test uses high-resolution mass spectrometry to measure plasma Aβ42/40 ratio and percent p-tau217. It combines both markers into one Amyloid Probability Score 2, scaled from 0 to 100.
A blood draw is simpler than amyloid PET imaging or spinal-fluid testing. In clinic use, the score helps a doctor decide whether amyloid is likely, unlikely, or uncertain enough to need follow-up testing.
How accurate is it in symptomatic adults?
In a 1,142-person validation study in symptomatic adults, results were checked against amyloid PET visual read or spinal-fluid biomarkers. According to C2N Diagnostics in its August 20 announcement, a Positive result had 97.6% positive predictive value and a Negative had 93.1% negative predictive value. Scores in the middle need more care.
According to NeurologyLive in its clearance summary, about 17.3% of study participants received an intermediate Likely Positive result with only 77.3% positive predictive value. That middle group often needs clinical judgment and possible PET or spinal-fluid confirmation. Patients should ask what a middle result would mean before giving blood.
Who qualifies, and who should not seek it?
The clearance covers adults age 40 and older with signs or symptoms of cognitive impairment. That age cutoff makes it the first cleared Alzheimer's blood test available down to age 40. It is not intended for screening people without symptoms.
According to C2N Diagnostics in its August 20 announcement, it is also not a stand-alone diagnosis and must be used with standard clinical workup. A doctor still needs history, cognitive testing, exams, and often brain imaging or labs. The blood result adds weight; it does not settle the cause alone.
What changes at a memory clinic visit?
Earlier amyloid insight can shorten the path from concern to plan. It can help a clinician decide who needs prompt PET or spinal-fluid confirmation, who can avoid it, and when treatment discussion is timely.
It can also help match patients to clinical trials that require amyloid evidence. For families, that can mean fewer wasted referrals and clearer next steps. Bring these items to the visit:.
- examples of memory, language, or thinking changes, with dates
- current medicines, sleep, mood, and medical conditions
- questions about confirmatory testing if the blood result is intermediate
- interest in trials, if enrollment matters to you
When and where is the cleared test available?
C2N said the FDA-cleared kit version was expected later in 2026. Its CLIA-validated lab version remained available through C2N's clinical laboratory during the transition.
Availability will vary by clinic, lab contracting, and insurance coverage. Ask your memory clinic whether it orders the C2N lab version now and how results return to your care team.
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