Antithrombin, Antigen
Also known as: AT3AG
Use
Not recommended as an initial test to detect antithrombin (AT) deficiency. It is used to determine the subtype in AT-deficient individuals. Antithrombin may be decreased due to liver disease, acute thrombosis, DIC, heparin therapy, asparaginase therapy, or other causes. In the absence of acquired conditions, the low value may represent a risk factor for thrombosis. A diagnosis of inherited antithrombin deficiency should be established only after other acquired causes of antithrombin deficiency have been excluded.
Special Instructions
Not provided.
Limitations
Antithrombin levels may be affected by various conditions including liver disease, acute thrombosis, disseminated intravascular coagulation (DIC), and certain therapies such as heparin and asparaginase therapy. The test should not be used as an initial test but rather for subtype determination in individuals with suspected or known antithrombin deficiency. External factors influencing antithrombin levels should be excluded before considering hereditary deficiency.
FDA ApprovedNew York Approved
Methodology
Immunoassay (Microlatex Particle-Mediated)
Biomarkers
LOINC Codes
- 27812-7 - AT III Ag Act/Nor PPP IA
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.5 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Transform from Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.
Storage Instructions
CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.
Causes for Rejection
Serum, EDTA plasma, clotted or hemolyzed specimens
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 8 hours |
| Refrigerated | Unacceptable |
| Frozen | 1 month |
Other tests from different labs that may be relevant