ADAMTS13 Inhibitor Assay
Test Mnemonic
ADM13I
CPT Codes
- 85335 - QTY (1)
LOINC ®
40824-5
Performing Laboratory
Cleveland Clinic Laboratories
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL | Plasma | Sodium citrate (Lt. Blue) | Centrifuge, aliquot and freeze ASAP. | Collection tube must be filled to total fill volume. Inadequately filled tube will be rejected. Invert to mix 3-4 times. Non-Testing Sites: Centrifuge sample; Aliquot plasma into a separate tube and label with Epic Beaker label. Specimen should be frozen (-20C or colder). |
Days Performed
Mon - Fri
Turnaround Time
2 - 4 days
Methodology
| Name | Description |
|---|---|
| Fluorescence Resonance Energy Transfer (FRET) |
Clinical Info
ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13) is responsible for regulating the interaction of platelets with von Willebrand factor (VWF) and proteolytic cleavage of VWF multimers at the Tyr(1605)-Met(1606) bond in the A2 domain of VWF. Measurement of ADAMTS13 activity and its inhibitor is crucial in the diagnosis of thrombotic thromboctyopenic purpura (TTP) and further differentiation of congenital (Upshaw-Schulman syndrome) versus acquired (e.g. autoimmune-related disorder) etiology. TTP is a rare life-threatening disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, variable organ damage and severely deficient ADAMTS13 activity. ADAMTS13 activity in TTP will be less than 5-10% in two-thirds of TTP patients and often related to autoantibodies that inhibit or clear ADAMTS13. Inhibitory antibody is observed in 44-93% of patients with severely deficient ADAMTS13 activity. Persistence of severe deficiency of ADAMTS13 activity or an inhibitor suggests high risk of relapse in symptomatic TTP.