Alzheimer’s Disease Biomarkers Panel, CSF
Test Overview
Clinical Utility
Please refer to Roche Press Release.
Method
Electrochemiluminescent immunoassay (ECLIA)
Analytical Platform
Roche cobas©
Method Description
Elecsys® AD CSF assay
Result Included
BetaAmyloid42 (ABeta42); Phosphorylated Tau 181 (pTau); Total Tau (Tau)
Specimen
Specimen Type
CSFSample must be collected in a Sarstedt FB CSF Collection tube 63.614.625 (blue cap) tube.
These tubes can be ordered from In-Common Laboratories, using the Client Supply Request form.
Containers
Collection Containers
Sarstedt 63.614.625 (blue cap) tube
Volume
Sample Volume
2.5 mL
Minimum Volume
1.5 mL
Collection & Handling
Collection Instructions
Specimens for Alzheimer’s Disease Biomarkers must be collected and handled as described in this downloadable document: Collection & Handling Instructions. Note: CSF must be collected into the Sarstedt 63.614.625 (blue cap) tube. β-amyloid peptides will adhere to plastics such as polystyrene. Failure to follow the recommended collection protocol may result in a falsely low Aβ42 result and contribute to an incorrect diagnosis of Alzheimer’s disease.
Handling Information
Specimens for Alzheimer’s Disease Biomarkers must be collected and handled as described in this downloadable document: Collection & Handling Instructions.
Stability
| Ambient | Refrigerated | Frozen |
|---|---|---|
| 12 hours | 14 days | 60 days |
Rejection Criteria
| Criteria | Specification |
|---|---|
| Specimen | Not collected as described |
Performance & Interpretation
Turnaround Time
7 days
Results
-
BetaAmyloid42 (ABeta42)pg/mL> 1030.0
-
Phosphorylated Tau 181 (pTau)pg/mL≤ 27.00
-
Total Tau (Tau)pg/mL≤ 300
-
pTau:ABeta42 Ratio≤ 0.0230
Comment
Compared to CSF concentrations of ABeta42, pTau, and Tau individually, the pTau/ABeta42 ratio has been shown to better correlate with Alzheimer's disease-related pathologic change as measured by amyloid PET scan.
Please note that improper specimen collection or handling technique may falsely decrease ABeta42 and increase the pTau/ABeta42 ratio.
Discrepancies in interpretation of the pTau/ABeta42 ratio compared to CSF concentrations of ABeta42, pTau, and/or Tau individually may relate to improper specimen collection/handling, inter-individual variation in beta-amyloid CSF concentration, a disorder related to CSF dynamics, and/or elevation in pTau due to a non-Alzheimer's disease-related pathologic change.
Clinical correlation is required. For patients with values near cutoffs, interpretation in the context of clinical history is particularly important.
Sample Report Normal
Sample Report Abnormal
Referral Location
Canada
Interface & Setup
HL7 Interface Codes
| Order Code | Result Name | Result Codes | Units |
|---|---|---|---|
| ALZD CSF | BetaAmyloid42 (ABeta42),CSF | 65228 | pg/mL |
| Phosphorylated Tau 181 (pTau),CSF | 65229 | pg/mL | |
| Total Tau (Tau),CSF | 65230 | pg/mL | |
| Alzheimer Interp (ABeta42,pTau,Tau),CSF | 65231 | ||
| pTau:ABeta42 Ratio,CSF | 65232 | ||
| Alzheimer Interp (pTau:ABeta42Ratio),CSF | 65233 | ||
| General Alzheimer's Comment,CSF | 65234 |
Test Version
Last Updated
2025-04-08