Antithrombin III Antigen
Also known as: AT3, Heparin Cofactor, AT III, AT III Antigen
Use
Antithrombin III Antigen measurement aids in characterization of antithrombin deficiency, which is associated with increased thrombotic risk. Type I deficiency shows reduced activity and antigen levels, while Type II shows relatively lower activity versus antigen levels. Acquired deficiency (e.g., from liver disease, nephrotic syndrome, heparin therapy, DIC, sepsis, L‑asparaginase chemotherapy) is more common than inherited forms.
Special Instructions
Not provided.
Limitations
Not provided.
Methodology
Immunoassay (Immunoturbidimetric)
Biomarkers
Antithrombin III Antigen
Protein
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.5 mL
Container
plastic vial
Collection Instructions
Draw blood in a 3.2% sodium citrate (light blue‑top) tube, mix gently by inverting 3‑4 times. Centrifuge 15 minutes at 1500 g within one hour. Transfer platelet‑poor plasma to new plastic vial(s), freeze immediately and transport on dry ice.
Causes for Rejection
Gross hemolysis; grossly lipemic; grossly icteric
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unacceptable |
| Refrigerated | Unacceptable |
| Frozen | 30 days |
Other tests from different labs that may be relevant