Thrombin−Antithrombin Complex

Clinical Use

Use

The Thrombin−Antithrombin Complex test is used to assess thrombin formation and antithrombin consumption. Elevated levels of TAT may be associated with various clinical conditions, such as advancing age, pregnancy, septicemia, disseminated intravascular coagulation, multiple trauma, acute pancreatitis, acute and chronic leukemia, preeclampsia, acute and chronic liver disease, and other predisposing causes of thrombosis. Increased TAT levels are also reported during heparin and fibrinolytic therapy, and they are markedly reduced after the first 24 hours of receiving oral anticoagulants. The test provides valuable information in diagnosing thrombotic events and tracking their resolution.

Special Instructions

Not provided.

Limitations

Results may be invalidated by traumatic venipuncture, prolonged stasis, or inadequate centrifuging. Incorrect mixing of the sample and sodium citrate may lead to falsely elevated levels. Elevated TAT levels may also result from inflammation and microvascular thrombosis in surgical patients or patients in acute distress. Testing conditions such as a difficult draw can spuriously increase test results.

Test Details

Methodology

Immunoassay (Sandwich Technique)

Biomarkers

Thrombin-Antithrombin Complex

Analyte

Concentration / Level

Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

LOINC Codes

Order Codes

14182-0 - TAT Ag PPP IA-mCnc

Result Codes

14182-0 - TAT Ag PPP IA-mCnc

Result Turnaround Time

3-9 days

Specimen

Plasma

Volume

2 mL

Minimum Volume

1 mL

Container

Blue-top (sodium citrate) tube

Collection Instructions

Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio. The sample should be mixed immediately by gentle inversion at least six times. Centrifuge and carefully remove the plasma using a plastic transfer pipette without disturbing the cells. Transfer to a Labcorp PP transpak frozen purple tube and freeze immediately. Submit separate frozen specimens for multiple tests.