Test Details
Methodology
Chemiluminescent enzyme immunoassay (CLEIA)
Result Turnaround Time
5 - 8 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
To indicate the ratio of beta-amyloid 42 proteins to beta-amyloid 40 proteins measured in the CSF to aid in the assessment of disease progression in patients with suspected or probable Alzheimer's disease.
Special Instructions
This test requires a dedicated Sarstedt CSF liquor low protein binding tube sent directly to the testing facility.
Limitations
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Specimen Requirements
Specimen
Cerebrospinal fluid (CSF)
Volume
8 mL
Minimum Volume
5 mL
Container
Sarstedt CSF Tube 62.610.018. Tube provided by Labcorp by request.
Collection Instructions
Collect cerebral spinal fluid (CSF) in Sarstedt CSF Tube 62.610.018. Tube must be filled 50% to 80% minimum. Specimen must be collected in Sarstedt tube directly and cannot be transferred from a regular collection tube. If first 1 mL is hemolyzed, discard and continue to draw sample.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 8 hours |
Refrigerated | 8 days |
Frozen | 30 days |
Freeze/thaw cycles | Stable x1 |
Storage Instructions
Refrigerate immediately (preferred), within 8 hours.
Freeze on arrival (at Labcorp).
Causes for Rejection
Wrong tube type; not stored at proper temperature; quantity not sufficient; sample transferred from another tube; gross hemolysis
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 505560 | Beta Amyloid 42/40 Ratio, CSF | 98584-6 | 505542 | Beta-amyloid 42 | pg/mL | 33203-1 |
| 505560 | Beta Amyloid 42/40 Ratio, CSF | 98584-6 | 505540 | Beta-amyloid 40 | pg/mL | 70072-4 |
| 505560 | Beta Amyloid 42/40 Ratio, CSF | 98584-6 | 505543 | Beta-amyloid 42/40 | 98485-6 | |
| 505560 | Beta Amyloid 42/40 Ratio, CSF | 98584-6 | 505539 | Interpretation: | 50398-7 | |
| 505560 | Beta Amyloid 42/40 Ratio, CSF | 98584-6 | 505544 | References: | 75608-0 | |
| Order Code | 505560 | |||||
| Order Code Name | Beta Amyloid 42/40 Ratio, CSF | |||||
| Order Loinc | 98584-6 | |||||
| Result Code | 505542 | |||||
| Result Code Name | Beta-amyloid 42 | |||||
| UofM | pg/mL | |||||
| Result LOINC | 33203-1 | |||||
| Order Code | 505560 | |||||
| Order Code Name | Beta Amyloid 42/40 Ratio, CSF | |||||
| Order Loinc | 98584-6 | |||||
| Result Code | 505540 | |||||
| Result Code Name | Beta-amyloid 40 | |||||
| UofM | pg/mL | |||||
| Result LOINC | 70072-4 | |||||
| Order Code | 505560 | |||||
| Order Code Name | Beta Amyloid 42/40 Ratio, CSF | |||||
| Order Loinc | 98584-6 | |||||
| Result Code | 505543 | |||||
| Result Code Name | Beta-amyloid 42/40 | |||||
| UofM | ||||||
| Result LOINC | 98485-6 | |||||
| Order Code | 505560 | |||||
| Order Code Name | Beta Amyloid 42/40 Ratio, CSF | |||||
| Order Loinc | 98584-6 | |||||
| Result Code | 505539 | |||||
| Result Code Name | Interpretation: | |||||
| UofM | ||||||
| Result LOINC | 50398-7 | |||||
| Order Code | 505560 | |||||
| Order Code Name | Beta Amyloid 42/40 Ratio, CSF | |||||
| Order Loinc | 98584-6 | |||||
| Result Code | 505544 | |||||
| Result Code Name | References: | |||||
| UofM | ||||||
| Result LOINC | 75608-0 |