von Willebrand factor-cleaving protease (VWFCP); ADAMTS13; ADAMTS 13
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ADAMTS-13 Activity with Reflex Inhibitor, Plasma
Test ID: ADAMR P
Test
Aliases/Synonyms
Method
ELISA
Report Includes
ADAMTS-13 Activity; ADAMTS-13 Inhibitor
Specimens
Clinical Utility
This test has not yet been approved by Health Canada. This test was validated by the special coagulation laboratory at St. Michael’s Hospital and is therefore considered a laboratory-developed test (LDT). Result must be interpreted within the clinical context.
ADAMT-13 Inhibitor will only be tested (and billed) when if Activity level is 10% or less.
Thrombotic Thrombocytopenic Purpura (TTP) is generally associated with a severe deficiency (i.e. < 10%) ADAMTS-13 activity. TTP may be primary (Upshaw-Schulman Syndrome) or secondary (acquired) and this assay does not distinguish between these two forms. The diagnosis of TTP should not be based solely on the ADAMTS-13 activity.
Patients with other thrombotic microangiopathies (e.g. Atypical Hemolytic Uremic Syndrome (aHUS), Hemolytic Uremic Syndrome (HUS), Disseminated Intravascular Coagulation (DIC)) or other conditions (sepsis, malignant hypertension, etc.) may have reduced ADAMTS-13 activity. However, ADAMTS-13 activity of 10% or lower is highly suggestive of TTP.
Of note: Transfusion of plasma or apheresis with plasma prior to sample collection may mask deficiency. Collect specimen prior to transfusion of any components and prior to apheresis. Collect specimen prior to transfusion of any components and prior to apheresis.
NOTE: To convert U/mL to percentage, % = U/mL x 100
Test Location
St. Michael's Hospital, 30 Bond Street, Toronto ON M5B 1W8
Test Version
22-Dec-2023
Specimen
Specimens
Sample Volume
2 x 1 mL
Patient Preparation
Collect specimen prior to transfusion of any components and prior to apheresis.
Collection & Handling
Collection Instructions
Ensure full draw with 9:1 ratio (9 parts blood to 1 part anticoagulant).
Handling Information
Prepare platelet-poor plasma and divide into two 1 mL aliquots. Freeze immediately. Store and send frozen.
Stability
| Ambient | 4 hours |
|---|---|
| Refrigerated | Unacceptable |
| Frozen | 14 days |
Additional Stability Information
Stable up to six months at -70C
Rejection Criteria
| Specimen | Not frozen |
|---|---|
| Hemolysis | Gross |
Test Version
22-Dec-2023
Performance / Interpretation
Method
ELISA
Turnaround Time
15 days
Results
| Name | Units | Reference Range | Conversion Factor | |
|---|---|---|---|---|
| ADAMTS-13 Activity | U/mL |
|
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| ADAMTS-13 Inhibitor | U/mL |
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Thrombotic Thrombocytopenic Purpura (TTP) is generally associated with a severe deficiency (i.e. ^lt;10%) ADAMTS-13 activity. TTP may be primary (Upshaw-Schulman Syndrome) or secondary (acquired) and this assay does not distinguish between these two forms. The diagnosis of TTP should not be based solely on the ADAMTS-13 activity.
Patients with other thrombotic microangiopathies (e.g. Atypical Hemolytic Uremic Syndrome (aHUS), Hemolytic Uremic Syndrome (HUS), Disseminated Intravascular Coagulation (DIC)) or other conditions (sepsis, malignant hypertension, etc.) may have reduced ADAMTS-13 activity. However, ADAMTS-13 activity of 10% or lower is highly suggestive of TTP. Of note: Transfusion of plasma or apheresis with plasma prior to sample collection may mask deficiency. Collect specimen prior to transfusion of any components and prior to apheresis.Collect specimenprior to transfusion of any components and prior to apheresis.This test has not yet been approved by Health Canada.This test was validated by the special coagulation laboratoryat St. Michael's Hospital and is therefore considered alaboratory-developed test (LDT). Result must be interpretedwithin the clinical context. NOTE: To convert U/mL to percentage, % = U/mL x 100 |
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Test Location
St. Michael's Hospital, 30 Bond Street, Toronto ON M5B 1W8
Test Version
22-Dec-2023
Interface / Setup
HL7 Interface Codes
| Order Code | Result Codes | Units |
|---|---|---|
| ADAMR P | 63123ADAMTS-13 Activity | U/mL |
| 63152ADAMTS13-Inhibitor | U/mL |
Test Version
22-Dec-2023