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24877 ADAMTS13 Evaluation (1295)

ADAMTS13 Evaluation (1295)
Test Code: ADAMTSO
Synonyms/Keywords
ADAMTS13 Activity, ADAMTS13, ADAMTS13 Inhibitor, VWF Cleaving Protease
Test Components
ADAMTS13 Evaluation is a reflexive testing algorithm for the evaluation of TTP. Activity is always performed. If the result is <= 30%, the inhibitor assay (1297) is performed.  If inhibitor result is <= 0.7 Inhibitor Units, the antibody assay (1299) is performed. 
Useful For
​Diagnosing Thrombotic Thrombocytopenic Purpura  (TTP)
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
Plasma​ ​Citrated Blue Top Tube (BTT) ​Three 0.5 mL aliquots ​Two 0.4 ml aliquots
OR​ ​ ​ ​ ​ ​
​Serum ​Red Top Tube ​Three 0.5 mL aliquots ​Two 0.4 ml aliquots
Collection Processing Instructions

Ship sample frozen.​

Specimen Stability Information
Specimen Type Temperature Time
​Plasma or Serum ​ ​ ​ ​Ambient ​7 days
​Refrigerated ​7 days
​Frozen -20 deg C ​2 weeks
​Frozen -80 deg C ​1 year
Rejection Criteria
Samples collected in EDTA are not acceptable.
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Versiti Wisconsin​ Monday through Friday​
Activity: 1-3 days
Inhibitor:  2-4 days
Antibody: 7-10 days

Activity: FRET based kinetic assay

Inhibitor:  Mixing Studies

Antibody:  ELISA​

Test Information

​ADAMTS13 is a plasma protein that regulates the interaction of platelets with von Willebrand factor. Absent or low ADAMTS13 activity allows formation of platelet microthrombi, which in turn obstruct arterioles and capillaries, generating the clinical sequelae of Thrombotic thrombocytopenic purpura (TTP).

The majority of adults with idiopathic TTP have a severe deficiency of ADAMTS13 with activity levels <10%. The low levels are often due to autoantibodies that inhibit or clear ADAMTS13. Patients with idiopathic TTP usually require therapeutic plasma exchange to achieve clinical remission. Patients with idiopathic TTP and severe ADAMTS13 deficiency are more likely to respond to plasma exchange therapy than patients without severe deficiency. Persistence of ADAMTS13 deficiency or an inhibitor/antibody during clinical remission suggests an increased risk for recurrence of symptomatic TTP. Identification of an autoimmune mechanism in idiopathic TTP explains the rationale for immunotherapy.

Congenital severe ADAMTS13 deficiency is an autosomal recessive disorder (Upshaw-Schulman syndrome). Patients may present as children or adults, and are at risk for recurrent episodes of TTP. Antibody to ADAMTS13 is usually not detected, and patients generally improve with plasma transfusion therapy for ADAMTS13 replacement.

Reference Range Information
Performing Location Reference Range
​Versiti Wisconsin
ADAMTS13 Activity: > or = 67%
ADAMTS13 Inhibitor: < or = 0.4 Inhibitor Units
ADAMTS13 Antibody:  < or = 18 Arbitrary Units​
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​85397 ​1 ADAMTS13 Activity​
​85335 ​1 ADAMTS13 Inhibitor (if performed)​
​83520 ​1 ADAMTS13 Antibody (if performed)​
Synonyms/Keywords
ADAMTS13 Activity, ADAMTS13, ADAMTS13 Inhibitor, VWF Cleaving Protease
Test Components
ADAMTS13 Evaluation is a reflexive testing algorithm for the evaluation of TTP. Activity is always performed. If the result is <= 30%, the inhibitor assay (1297) is performed.  If inhibitor result is <= 0.7 Inhibitor Units, the antibody assay (1299) is performed. 
Ordering Applications
Ordering Application Description
​Centricity ​ADAMTS13 Evaluation (1295)
​Cerner ​ADAMTS13 Evaluation (1295)
​COM ​ADAMTS13 Evaluation
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
Plasma​ ​Citrated Blue Top Tube (BTT) ​Three 0.5 mL aliquots ​Two 0.4 ml aliquots
OR​ ​ ​ ​ ​ ​
​Serum ​Red Top Tube ​Three 0.5 mL aliquots ​Two 0.4 ml aliquots
Collection Processing

Ship sample frozen.​

Specimen Stability Information
Specimen Type Temperature Time
​Plasma or Serum ​ ​ ​ ​Ambient ​7 days
​Refrigerated ​7 days
​Frozen -20 deg C ​2 weeks
​Frozen -80 deg C ​1 year
Rejection Criteria
Samples collected in EDTA are not acceptable.
Useful For
​Diagnosing Thrombotic Thrombocytopenic Purpura  (TTP)
Test Components
ADAMTS13 Evaluation is a reflexive testing algorithm for the evaluation of TTP. Activity is always performed. If the result is <= 30%, the inhibitor assay (1297) is performed.  If inhibitor result is <= 0.7 Inhibitor Units, the antibody assay (1299) is performed. 
Reference Range Information
Performing Location Reference Range
​Versiti Wisconsin
ADAMTS13 Activity: > or = 67%
ADAMTS13 Inhibitor: < or = 0.4 Inhibitor Units
ADAMTS13 Antibody:  < or = 18 Arbitrary Units​
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Versiti Wisconsin​ Monday through Friday​
Activity: 1-3 days
Inhibitor:  2-4 days
Antibody: 7-10 days

Activity: FRET based kinetic assay

Inhibitor:  Mixing Studies

Antibody:  ELISA​

For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​85397 ​1 ADAMTS13 Activity​
​85335 ​1 ADAMTS13 Inhibitor (if performed)​
​83520 ​1 ADAMTS13 Antibody (if performed)​
For most current information refer to the Marshfield Laboratory online reference manual.