Alzheimer Disease Evaluation, Spinal Fluid
Use
This test is useful for assessing adults with cognitive impairment being evaluated for Alzheimer disease and other causes of cognitive impairment. It measures beta-amyloid (1-42) (Abeta42), total Tau, and phosphorylated Tau (p-Tau181) in cerebrospinal fluid (CSF), which are key biomarkers in the differential diagnosis of Alzheimer's disease and other cognitive disorders. The p-Tau181/Abeta42 ratio provides excellent concordance with amyloid positron emission tomography (PET) imaging, aiding in the assessment of amyloid deposition presence in Alzheimer's disease patients.
Special Instructions
Not provided.
Limitations
The test results should not be used to predict the development of dementia or other neurologic conditions or to monitor therapy response. An abnormal result does not definitively diagnose Alzheimer's disease or another cognitive disorder. There may be interindividual differences affecting Abeta42 and p-Tau concentrations, impacting result interpretations. Performance characteristics for diverse racial and ethnic groups have uncertainty due to limited study populations.
New York Approved
Methodology
Immunoassay (ECLIA)
Biomarkers
Beta-amyloid 1-42
ProteinPhosphorylated Tau (p-Tau181)
ProteinTotal Tau
Protein
LOINC Codes
- 104134-2 - Dementia eval pnl CSF
- 41027-4 - Tau Prot/AL beta42 CSF-Rto
- 69048-7 - Immunologist review
- 33203-1 - AL beta42 CSF-mCnc
- 72260-3 - p-tau181 CSF IA-mCnc
- 30160-6 - Tau Prot CSF-mCnc
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Cerebrospinal Fluid
Volume
1.5 to 2.5 mL
Minimum Volume
See Specimen Required
Container
Sarstedt CSF False Bottom Tube 63.614.625
Collection Instructions
Perform lumbar puncture, discard first 1 to 2 mL of CSF, collect into specified tubes at least 50% full, send in original tube, do not aliquot. Refer to collection PDF for more details.
Storage Instructions
Store refrigerated (preferred), ambient or frozen according to stability guidelines.
Causes for Rejection
Gross hemolysis, gross icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 12 hours |
| Refrigerated | 14 days |
| Frozen | 60 days |