What is ATN? 

The ATN framework establishes a means for classifying biomarkers based on the biological evidence of Alzheimer’s disease that each marker provides1. These markers are divided into three categories to reflect the three primary biological changes associated with Alzheimer’s: 

  • A for amyloid plaques: Accumulations of beta-amyloid 42 proteins begin to form plaques in the brain years before initial symptom onset 
  • T for tau tangles: The beta-amyloid 42 accumulation causes misfolding of tau proteins, which tangle into knots and disrupt normal brain cell function 
  • N for neurodegeneration: Brain cell functional impairment causes the cells to die, which exacerbates the characteristic cognitive impairment symptoms observed in Alzheimer’s patients


Beta-Amyloid 42/40 RatioAssess levels of pathologic change consistent with Alzheimer’s disease


Phosphorylated Tau 181 (pTau181)


Neurofilament Light Chain (NfL)Assess disease severity by measuring neurodegeneration

What is the ATN Profile test?

This is the first Alzheimer's blood test that combines three Alzheimer's biomarkers that is simple, non-invasive and gives objective evidence for the biological changes associated with Alzheimer's disease. The test is intended to be used by clinicians for patients that may be undergoing a dementia workup.

Does the ATN Profile diagnose Alzheimer’s disease?

Biological confirmation of disease is necessary for diagnosis. This test provides evidence of the biological changes that are consistent with Alzheimer’s disease. However, Alzheimer’s still requires a clinical diagnosis based on clinical observation and cognitive testing.

How accurate is the test?

The ATN Profile was clinically validated using 200 samples from a well-studied cohort in which all samples were characterized with patient age, sex, amyloid PET status, and clinical diagnosis. The beta-amyloid 42/40 ratio assay showed a ROC analysis area under the curve (AUC) of 0.944, with a sensitivity of 96% and specificity of 86.7%.


Explore these resources to learn more about our ATN Profile

ATN Flyer for Primary Care

Learn more about the ATN Profile and its usage in a primary care setting

ATN Whitepaper

Our whitepaper detailing the ATN Profile background and performance

Labcorp can help meet your neurology needs

Contact a Labcorp representative to learn more about how we can help meet your neurology testing needs


Labcorp is accelerating technologies from the lab to the clinic. As a single lab services provider, we are expanding our comprehensive neurology portfolio to help you do more for your patients. Please click the link below to learn more about our full neurology program.


  1. Jack, CR, et.al. (2016). A/T/N: An unbiased descriptive classification scheme for Alzheimer disease biomarkers. Neurology, 87(5), 539-547. 
  2.  Hviid, C. V. B., Knudsen, C. S., & Parkner, T. (2020). Reference interval and preanalytical properties of serum neurofilament light chain in Scandinavian adults. Scandinavian journal of clinical and laboratory investigation, 80(4), 291-295. 
  3. Khalil, M, et.al. (2020). Serum neurofilament light levels in normal aging and their association with morphologic brain changes. Nature communications, 11(1), 812.