ADAMTS13 Activity (Sendout)
General Information
Lab Name
ADAMTS13 Activity (Sendout)
Lab Code
RADM13
Epic Name
ADAMTS 13 Activity (Sendout)
External Test Id
3260-01
Description
Test Information: ADAMTS13 activity is measured by a Fluorescence Resonance Transfer (FRET) Assay in which fluorescence is detected when a synthetic von Willebrand Factor peptide (VWF73) is cleaved by ADAMTS13.
ADAMTS13 is a plasma protein that cleaves ultra-large VWF multimers, thus regulating the interaction of platelets with von Willebrand. Low ADAMTS13 activity is found in patients with thrombotic thrombocytopenia purpura (TTP). Very low levels of activity can be seen in congenital TTP, whereas modestly decreased levels have been reported in a number of clinical settings. ADAMTS13 activity levels may help differentiate TTP from other microthrombolytic disorders such as HUS or atypical HUS.
Algorithm: If the activity level is <30%, the ADAMTS 13 Inhibitor and ADAMTS 13 Antibody may be performed at additional charge.
Synonyms
3260-01, ADAMTS13, ATS-13, TTP, Von Willebrand Factor Protease Activity & Inhibitor for Thrombotic Thrombocytopenia Purpura, VWF Metalloproteinase
Components
| Code | Name |
|---|---|
| RADMNA | ADAMTS13 Protease Act (Sendout) |
| RADMIA | ADAMTS13 Inhibition (Sendout) |
| RADMAB | ADAMTS13 Antibody (Sendout) |
| RADMSC | ADAMTS13 Specific Comment (Sendout) |
| RADMCM | ADAMTS13 Comments (Sendout) |
| S2AD13 | ADAMTS13 Activity Testing Lab |
Interpretation
Method
Fluorescence Resonance Transfer (FRET)
Reference Range
See individual components
Interferences and Limitations
Caution should be exercised in the interpretation of any assay for ADAMTS13; the results should only be considered in the conjunction with the patient’s clinical condition. Previous transfusion, plasma infusion, plasma exchange, or free hemoglobin in the plasma (>2g/L) may affect the level of ADAMTS13 as well as any inhibitors that are present.
Ordering & Collection
Specimen Type
Collection
3 mL BLUE TOP (CITRATE) tube
Note: Fill the entire tube to ensure correct blood/anti-coagulant ratio. Short-draw samples are not acceptable and do not meet the criteria for testing.
Forms & Requisitions
- Bloodworks Northwest Platelet Immunology Laboratory Requisition
Handling Instructions
Outside Laboratories: Centrifuge for 10 minutes and remove plasma. Centrifuge the plasma again for another 10 minutes. Transfer plasma to a separate vial within 4 hours of collection. Freeze plasma (minimum 0.5 mL) at -20°C while awaiting shipment. Transport samples frozen on dry ice.
Quantity
requested: 1 mL Citrated plasma
minimum: 0.5 mL Citrated plasma
Processing
Forward specimen to Coagulation Lab for processing. Samples must be centrifuged and the plasma separated within 4 hours of collection.
Coagulation: Double-spin the sample and freeze plasma at -20°C (Sendouts frozen rack).
Sendouts:
- Order Bloodworks Northwest Test: 3260-01
- Package the sample with a copy of the Bloodworks NW Platelet Immunology Lab requisition in a biohazard bag (one patient per bag) and place on dry ice.
- The name of the ordering provider should be included on the requisition.
- Orders received with multiple patient samples/requisitions in the same biohazard bag will be rejected by Bloodworks NW.
- Send routine samples via scheduled DLMP Courier shipments or Delivery Express, as needed.
- Urgent Sample Handling: In select cases, providers may arrange with Bloodworks NW to perform testing outside of their regular performance days or times. If approval is obtained, the BWNW Platelet Lab will contact CAST to request expedited transport of a sample. CAST will create an HC1 task for (UW-MT or HMC) PSPS asking lab staff to prioritize transport. Urgent samples should be sent immediately via Delivery Express to ensure that they reach Bloodworks before the cutoff for the designated run.
Fred Hutch: Send samples directly to Bloodworks Northwest.
Performance
LIS Dept Code
Sendouts (SO)
Performing Location(s)
| Sendout |
Bloodworks Northwest Platelet Immunology/Genomics Laboratory (Central HPG)
921 Terry Ave |
Genomics Testing Laboratory (for RBC genotyping): (206) 689-6269 Platelet Immunology Laboratory: (206) 689-6543 Laboratory staffed for questions Monday through Friday, 08:00 am to 04:30 pm. |
|---|
Frequency
Performed: Monday, Wednesday, and Friday. TAT: 2-3 business days.
Available STAT?
Expedited testing or testing on unscheduled days may be available by direct arrangement with Bloodworks Northwest Platelet Immunology Lab. Contact the lab at 206-598-6543.