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.

Note: 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

Blood

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. Send 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.
  • Include the name of the ordering provider on the Bloodworks requisition.
  • Send sample on dry ice via Delivery Express courier.

Fred Hutch: Send samples directly to Bloodworks Northwest.

Performance

LIS Dept Code

Sendouts (SO)

Performing Location(s)

Sendout Bloodworks Northwest
206-292-6500

921 Terry Ave
Seattle, WA 98104

Other Locations/Notes

Bloodworks Northwest Platelet Immunology Lab, Room 619, 921 Terry Ave, Seattle, WA 98104

  • Phone: 206-689-6543

Frequency

Performed: Monday, Wednesday, and Friday. TAT: 2-3 business days.

Available STAT?

No

Billing & Coding

CPT codes

85397

LOINC

53622-7

Interfaced Order Code

UOW3865