Days Set Up
Monday - Friday, 8am - 4pm one run per day.
Specimen must be received by noon or will be tested the next business day.
Testing will not be performed on holidays or weekends .
Analytic Time

2 hours

MiChart Code
ADAMTS13 Activity
Soft Order Code

Test Updated:


von Willebrand Factor Cleaving Protease
VWF Cleaving Protease
ADAMTS13 Inhibitor
ADAMTS13 Activity

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Test Overview

Test Methodology
Test Usage

Severe deficiency of ADAMTS-13 (activity <5-10%) may be acquired or congenital, and is a relatively specific finding in patients with a clinical diagnosis of thrombotic thrombocytopenic purpura (TTP). TTP is a rare and potentially fatal thrombotic microangiopathy syndrome, characterized by symptoms such as thrombocytopenia, microangiopathic hemolytic anemia (intravascular hemolysis with presence of schistocytes), neurological symptoms, fever, and renal dysfunction. In this patient population, persistence of severe ADAMTS-13 deficiency during clinical remission is associated with an increased risk for recurrent clinical episodes of TTP. Mild to moderate deficiency of ADAMTS-13 activity has also been observed in multiple medical conditions.

Reference Range

ADAMTS-13 Activity >67%. ADAMTS-13 Inhibitor <30%.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Specimen Requirements

Collection Offsite

Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a polypropylene plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.

Blue Top Tube
Normal Volume
Full 2.7 mL tube or 1 mL plasma aliquot
Minimum Volume
Full 1.8 mL tube or 1 mL plasma aliquot

Billing Information

CPT Code
Pro Fee Code

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.