Laboratory Medicine Program

ADAMTS-13 Activity

Clinical Decription:
The ADAMTS-13 protease is responsible for cleaving ultra-large vWF (ULVWF) multimers. Autoantibodies inhibit this proteolytic activity, resulting in the accumulation of non-cleaved ULVWF in the plasma. This is believed to be the major cause for thrombotic thrombocytopenic purpura (TTP). The assay allows for the differentiation of congenital TTP (Upshaw-Schulman Syndrome), rarely seen and presenting in childhood, from acquired TTP. Antibodies are only exhibited in acquired TTP, and not seen in USS.

Method: ELISA; Manual

Component Tests Used: ADAMTS-13 Activity, ADAMTS-13 Inhibitor (if required)

Reference Ranges Used:
40 - 130%

Specimen Type: Citrated plasma
Collected In: 3.2% Sodium Citrate
Volume: 1.0 mL (minimum: 1.0 mL)

Shipping: Send frozen on dry ice.

Special Instructions: The specimen must be double-centrifuged to obtain a platelet-poor plasma specimen (Plt <10x10E9/L): 1. Immediately centrifuge specimen at 1500xG for 10 minutes. 2. Separate the plasma from the platelet/buffy coat and transfer into a clean plastic tube. 3. Centrifuge the separated plasma at 1500xG for 10 minutes. 4. Transfer 1.0 to 2.0 mL of the double-centrifuged plasma into a clean plastic tube, leaving approx. 200 uL for discard. 5. Freeze plasma aliquot immediately for storage. Maintain frozen for shipping and handling.

Testing Schedule(s): Weekly.

Turnaround Time: 7 days

For more information, call 416.340.5227 or 1.866.865.5227