ALZpath pTau217 Reference Interval Interface

Welcome to the ALZpath pTau217 Reference Interval Interface. This interactive tool provides a visualization for individual patient plasma ALZpath pTau217 values in the context of reference values in a cognitively healthy population without amyloid pathology.

Interpreting ALZpath pTau217 Levels in the Context of Health

ALZpath pTau217 shows exceptional accuracy in detecting amyloid positivity, tau positivity, and discriminating the presence of Tau tangles in amyloid positive individuals.

The ALZpath Reference Interval Interface enables physicians to review how patient ALZpath pTau217 levels compare to those of a healthy population.  Our objective is to improve the precision and dependability of Alzheimer’s disease diagnosis and monitoring.  

How to Use the Reference Interval Interface

Enter ALZpath pTau217 Value:

  • Following an ALZpath pTau217 test, the ordering physician will receive a secure email with the ALZpath pTau217 test result. 
  • Locate the patient ALZpath pTau217 value from the results report.
  • Enter the ALZpath pTau217 value into the designated input field on the interface.

Enter Patient Age:

  • Adjust the slider to the appropriate age of the patient for whom the ALZpath pTau217 value was obtained.

Interpreting Results:

  • After entering the patient ALZpath pTau217 level and age, the interface will represent the patient with a red cross.
  • If the red cross indicating the patient values is outside of the purple band representing the reference values obtained in a healthy control population, the patient is outside of biomarker levels for healthy individuals for that age. Conversely, if the red cross is below or overlayed onto the purple area of the interface, this indicates that the patient biomarker level is within levels seen in a healthy, amyloid negative population. 
  • Does it matter how close a patient result is to the reference values shown in purple?
    • In the interface, the dark central line is the mean of the population and the shaded purple regions are percentiles around the mean.
    • This means, for example, if a patient is in the shaded region for the 75-95% percentile, then that patient has a higher pTau217 level than 75-95% of healthy individuals. If the patient is in the middle of the 75-95% percentile color band, at the 85% percentile, then only 15% of a healthy population have higher pTau217 levels than that patient.
    • The lower a patient pTau217 level is, compared to the mean, the less likely the patient is to display Alzheimer’s disease pathology. Conversely, a pTau217 above the 75-95% percentile range is associated with a higher likelihood of tau tangles and amyloid plaques, the hallmarks of Alzheimer’s disease.

Reference Interval Interface

Origins of the ALZpath pTau217 Reference Interval Data

The reference intervals provided here are derived from the Australian Imaging, Biomarkers & Lifestyle (AIBL) cohort. This large-scale longitudinal cohort serves as a cornerstone for illuminating the trajectory of Alzheimer’s disease development focused on Alzheimer’s biomarkers. We are grateful to the AIBL research team for their important work on this valuable study. 

Notes on the Use of The Reference Interval Interface

  • The ALZpath pTau217 Reference Interval Interface is specific to ALZpath pTau217 and should not be used with other pTau assays.
  • Education, sex, and APOE status do not influence the reference intervals for ALZpath pTau217 and therefore are not considered in this interface.
  • The ALZpath Reference Interval Interface supports ages 60-85 years of age based on the data supporting this interface.
  • ALZpathDx is not intended for patients younger than 55 years or for patients without signs or symptoms of cognitive decline and has not been approved by the U.S. Food and Drug Administration (FDA).
  • Reference intervals were determined using an upper 95th percentile obtained using a rank-based method, as recommended by the International Federation for Clinical Chemistry and Laboratory Medicine (IFCC).
  • Conducted in accordance with Clinical & Laboratory Standards Institute (CLSI) Guidelines for the best means to establish a reference interval.

Get in Touch

Have questions or need more information about the interface? Click the button below to contact us.