UW Hospital and Clinics Lab Test Directory
| Test Name: |
|
ADAMTS13 Activity
|
|
|
|
|
|
|
| Test Code(s): |
|
ADAM13 / HCADAM13
|
|
|
|
|
|
|
| CPT Code(s): |
|
85397
|
|
|
|
|
|
|
| Methodology: |
|
Fluorescence Resonance Energy Transfer (FRET)
|
|
|
|
|
|
|
| Clinical Significance: |
|
Low levels of ADAMTS13 are associated with a clinical diagnosis of Thrombic thrombocytopenic purpura (TTP).
|
|
|
|
|
|
|
| Testing Site: |
|
Testing will be sent to an approved reference laboratory.
|
|
|
|
|
|
|
| Turnaround Time: |
|
Routine: 7 - 10 days.
|
|
|
|
Specimen Requirements
|
|
|
|
| Specimen: |
|
Blood
|
|
|
|
|
|
|
| Collection Container: |
|
Preferred: Light blue top (3.2% NaCitrate)
Also Acceptable:
Red top
|
|
|
|
|
|
|
| Collection Volume: |
|
Preferred: Full tube
Pediatrics: Full tube.
|
|
|
|
|
|
|
| Sample Analyzed: |
|
Plasma or serum
|
|
|
|
|
|
|
| Volume Required: |
|
Preferred: 0.5 mL
Pediatrics: 0.2 mL
|
|
|
|
|
|
|
| Specimen Processing: |
|
Centrifuge specimen to yield platelet poor plasma (platelet count should be less than 10 K/uL). Separate plasma and transfer to plastic tube or vial. Freeze plasma within 4 hours of collection at -20°C or below.
|
|
|
|
|
|
|
| Specimen Transport: |
|
Transport specimen to UWHC Core Laboratory (B4/220). Transport frozen plasma on dry ice if coming from outreach location.
|
|
|
|
|
|
|
| Unacceptable Criteria: |
|
Hemolyzed or clotted specimens are unacceptable.
|
|
|
|
|
|
|
| Stability: |
|
Ambient: 4 hours
Refrigerated: 7 days
Frozen: 14 days at -20°C; 1 year at -80°C
|
|
|
|
Interpretation
|
|
|
|
|
Reference Interval:
|
|
Activity > or = 67%
|
|
|
|
|
|
|
| Test Limitations: |
|
Recent plasma exchange therapy may alter ADAMTS13 activity and inhibitor levels. Hemolysis with plasma free hemoglobin greater than 2 g/L or an elevated bilirubin level can cause artifactually low ADAMTS13 activity and false positive inhibitor results.
|
|
|
|
|
|
|
von Willebrand Factor Cleaving Protease
|
