ADmark® Alzheimer's Evaluation, CSF
Test code
CPT code(s)*
Clinical significance
Test resources
Test FAQ
Details
Includes
Beta-Amyloid (1-42), CSF
tTau, CSF
pTau181, CSF
tTau/Abeta42 Ratio
pTau181/Abeta42 Ratio
Methodology
Electrochemiluminescence (ECLIA)
Alternative name(s)
total tau,ttau,AB 42,Alzheimer’s Disease,Alzheimer's CSF,FDA CSF test,Amyloid beta 42,ptau 181
Specimen requirements | |
|---|---|
| Patient preparation | None Specified |
| Preferred specimen(s) | 2.5 mL CSF collected in a 2.5 mL Sarstedt low-bind false bottom tube (63.614.625, Quest Diagnostics supply part # ST100) |
| Alternative specimen(s) | 1.5 mL CSF collected in a 1.5 mL Sarstedt low protein-binding tube (72.703.600) |
| Minimum volume | 1 mL Sarstedt low-bind false bottom tube • 0.7 mL Sarstedt low protein-binding tube |
| Collection instructions | Perform lumbar puncture (LP) using gravity drip collection method. Avoid the use of syringes or tubings. Perform lumbar puncture (LP) before noon. Do not use the first 2 mL of CSF for AD Biomarker measurement. Subsequently, collect 2.5 mL of CSF directly into 2.5 mL Sarstedt (63.614.625) tube, or 1.5 mL of CSF directly into 1.5 mL Sarstedt (72.703.600) tube, for AD biomarker measurements. Filling tube at least 50% full is recommended. Each sample should be visually inspected for hemolysis. Do not use CSF samples which appear reddish. Instead, collect additional clear (non-hemolytic) CSF in a new Sarstedt tube. Do not process the CSF sample before transport to the measuring site (i.e., no mixing/inverting, no tube transfers, no aliquoting, and normally no centrifugation) until measurement. It is strongly recommended that the sample be kept at 2 to 8° C or -15 to -25° C during transport and storage up to the time of measurement. Only the specimen listed is acceptable for use with this assay. Standard CSF polystyrene collection tubes are NOT acceptable as exposing CSF to polystyrene tubes may decrease Abeta42 concentrations. |
| Transport container | CSF tube 63.614.625 (Sarstedt) |
| Transport temperature | Refrigerated (cold packs) |
| Specimen stability | Room temperature: 5 days Refrigerated: 14 days Frozen: 56 days |
| Reject criteria | Gross hemolysis • Polystyrene and polypropylene tubes other than Sarstedt (63.614.625) 2.5 mL and (72.703.600) 1.5 mL |
Reference Range(s)
| Beta-Amyloid (1-42), CSF | Not established |
| tTau, CSF | Not established |
| pTau181, CSF | Not established |
| tTau/Abeta42 Ratio | ≤0.28 |
| pTau181/Abeta42 Ratio | ≤0.023 |
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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