AD-Detect™ ABeta 42/40 and p-tau217 Evaluation, Plasma
Test code
CPT code(s)*
Clinical significance
Test resources
Test FAQ
Details
Includes
AD-Detect Likelihood Score Interpretation
AD-Detect Beta-Amyloid 42/40 Ratio, Plasma
AD-Detect Phosphorylated tau217, Plasma
AD-Detect Likelihood Score
Methodology
Immunoassay (IA) • Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)
Assay category
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Alternative name(s)
Phosphorylated tau,ptau 217,AB 42,Dementia,Alzheimer's Diagnostic panel,Alzheimer’s Disease,Alzheimer's diagnosis,Amyloid beta 42,Phospho tau
Specimen requirements | |
|---|---|
| Patient preparation | Patients should be cautioned to stop biotin consumption at least 72 hours prior to collection of a sample |
| Preferred specimen(s) | 2.5 mL total plasma collected in a K2 EDTA (lavender-top) tube split into two equal aliquots |
| Minimum volume | 1.2 mL |
| Collection instructions | Quest Diagnostics does not perform this test for individuals under the age of 18. Pre-test and post-test counseling is strongly recommended. Collect blood into a K2 EDTA (lavender-top) tube and mix by inversion 10 times. Centrifuge to separate plasma from cells within 1 hour of collection. Carefully transfer plasma into 2 separate polypropylene tubes or 2 separate Quest issued polypropylene pour-off/transfer tubes. Do not transfer to conical tubes. Store frozen. |
| Transport container | Transport tube(s) |
| Transport temperature | Frozen |
| Specimen stability | Room temperature: Unacceptable Refrigerated: 72 hours Frozen: 28 days |
| Reject criteria | Moderate or gross hemolysis • Specimen collected in a glass, polystyrene, or polycarbonate tube • K3 EDTA tube • K2 EDTA gel separator tube |
Reference Range(s)
| ABeta 42 | Not Established |
| ABeta 40 | Not Established |
| ABeta 42/40 Ratio | ≥0.170 |
| AD Detect p-tau217 | ≤0.15 pg/mL |
| AD Detect Likelihood Score | |
| Likelihood of amyloid PET positivity | |
| Low Likelihood | <0.3254 |
| Indeterminate | 0.3254-0.6460 |
| High Likelihood | >0.6460 |
Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.
*The CPT codes provided are based on AMA guidance and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.
This material contains content from LOINC® (http://loinc.org). The LOINC Table, LOINC Table Core are copyright © 1995-2019, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee and is available at no cost under the license at http://loinc.org/license.
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