ADAMTS13 Activity Assay
Test Mnemonic
ADM13A
CPT Codes
- 85397 - QTY (1)
- 85390 - QTY (1)
LOINC ®
53622-7
Performing Laboratory
Cleveland Clinic Laboratories
FDA Category
Laboratory Developed Test
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL | Platelet-poor plasma | Sodium citrate (Lt. Blue) | Frozen |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | 4 hrs |
| Frozen | 14 days at -20C; 6 months at -70C |
Days Performed
Mon - Fri
Turnaround Time
2 - 4 days
Methodology
| Name | Description |
|---|---|
| Enzyme-Linked Immunosorbent Assay (ELISA) |
Reference Range
| ADAMTS13 Activity | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Years | 99 Years | Normal | > or = 68 | % | Years | 99 Years | Urgent | <10 | % |
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.