ADAMTS13 Activity with Reflex to Inhibitor : 14532

Message

CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Test Code

ADAMST or 14532

Alias/See Also

VWF CLEAVING PROTEASE, vWF-CP, von Willebrand Factor, vWF Protease Activity

CPT Codes
85397

Includes

If ADAMTS13 Activity is less than or equal to 0.30 IU/mL , ADAMTS13 Inhibitor will be performed at an additional charge (CPT code: 85335).

Preferred Specimen

1 mL frozen plasma collected in a 3.2% sodium citrate (light blue-top) tube

Minimum Volume

0.5 mL

Instructions

Please submit a separate, frozen vial for each special coagulation assay ordered. Draw blood in a light blue-top tube containing 3.2% sodium citrate, mix gently by inverting 3-4 times. Centrifuge 15 minutes at 1500 g within one hour of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial.
Freeze immediately and transport on dry ice

Transport Container

Transport container

Transport Temperature

Frozen

Specimen Stability

Ambient: Unacceptable
Refrigerated: Unacceptable
Frozen: 21 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross Hemolysis, Grossly Lipemic, Grossly Icteric

Methodology
Immunoassay

Setup Schedule

Sunday - Thursday

Report Available

2-4 days (From receipt at performing laboratory)

Limitations

This test was performed using a kit that has not been cleared or approved by the FDA. The analytical performance characteristics of this test have been determined by Quest Diagnostics. This test should not be used for diagnosis without confirmation by other medically established means.

Reference Range

ADAMTS13 Activity 0.68-1.63 IU/mL
ADAMTS13 Inhibitor <0.4 BEU

Clinical Significance

ADAMTS13 Activity with Reflex to Inhibitor - ADAMTS-13 is a zinc metalloprotease that cleaves ultra large vWF multimers. Studies have shown that low levels of ADAMTS-13 activity are associated with thrombotic thrombocytopenic purpura (TTP), a life-threatening hematological condition characterized by a low platelet count, microvascular thrombi, red cell fragmentation, and renal complications. Congenital TTP is a rare inherited disease caused by mutations within the ADAMTS-13 gene, which result in the production of non-functional protein. The acquired form of TTP is an autoimmune-like disorder caused by the development of autoantibodies to ADAMTS-13 that inhibits enzyme activity.

Note: In the FDA approved test used at Quest Diagnostics, results are reported using international units (IU) per mL and not in percent (%), typically described in many studies. To convert to %, multiply IU/mL by 100%. For example, 0.3 IU/mL would be equivalent to 30% ( 0.3 IU/mL x 100%).

Performing Laboratory
Quest Diagnostics

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.