In August 2026 the FDA cleared PrecivityAD2, a blood test that estimates amyloid buildup linked to Alzheimer's disease, for adults 40 and older with cognitive symptoms. Primary care patients can compare it with two other cleared amyloid blood tests by checking age range, care setting, and how results fit with standard clinical workup.
C2N Diagnostics announced the clearance on Aug. 20, 2026, for use alongside standard exams and history, not as a stand-alone answer clearance announcement. The test is meant for people already having memory or thinking concerns, not for routine screening 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 Fixfirst — Use this primary source to verify the official guidance.
Table of Contents
- Who can use PrecivityAD2?
- What does the test measure?
- How accurate was it in validation?
- How do the three cleared options compare?
- What should you ask your doctor?
Who can use PrecivityAD2?
PrecivityAD2 is limited to adults 40 and older who have signs, symptoms, or complaints of cognitive decline. FDA clearance requires use with standard clinical workup, and the test is not intended as screening or as a stand-alone diagnostic, according to Patient Care Online clearance details.
In practice, that means new forgetfulness, confusion with tasks, word-finding trouble, or a family concern raised at a primary care visit. Bring specific examples, timing, medications, and sleep or mood changes so the clinician can decide if amyloid testing fits.
What does the test measure?
The test uses high-resolution mass spectrometry to measure plasma Abeta42/40 and p-tau217 relative to non-phosphorylated tau217. Those results combine into an Amyloid Probability Score 2 from 0 to 100.
A higher score signals a higher likelihood of brain amyloid found by confirmatory testing. Your clinician reads the score with cognitive exams, medical history, and other causes of symptoms, then decides on referral, imaging, or spinal fluid testing.
How accurate was it in validation?
In a 1,142-participant study against amyloid PET or cerebrospinal fluid testing, a positive result had 97.6 percent positive predictive value and a negative result had 93.1 percent negative predictive value, according to Patient Care Online validation results. That means most positives matched amyloid on PET or spinal fluid, and most negatives matched absence of amyloid. Results still need clinical context because other brain conditions can cause similar symptoms.
How do the three cleared options compare?
By August 2026 primary care patients had at least three cleared amyloid blood tests to discuss. FixFirst Research reports PrecivityAD2 is the first cleared for symptomatic adults as young as 40, while Fujirebio Lumipulse and Roche Elecsys pTau181 are cleared only for ages 55 and up test comparison.
Age cutoff, clinic access, and whether you need a rule-in or rule-out answer matter most. Ask which test your clinic offers and which age and workflow rules apply to you.
- PrecivityAD2: age 40 and older with cognitive symptoms, paired with clinical workup.
- Lumipulse amyloid test: age 55 and older, earlier test aimed at specialty settings.
- Elecsys pTau181: age 55 and older, positioned as a primary-care rule-out test.
What should you ask your doctor?
Ask whether the clinic offers the FDA-cleared PrecivityAD2 or the existing CLIA-validated version through C2N's laboratory. C2N said the FDA-cleared version was expected later in 2026, while the CLIA version remains available.
Blood testing can be less invasive and more accessible than costly PET scans or spinal taps that often involve waitlists and specialty-center travel, according to Being Patient blood test access. Ask how blood results would change your next step, and what confirmatory testing you would accept.
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