Antithrombin-III (synonym: AT-III) is a protein (protein) from the blood clotting system. It inhibits blood clotting factors (factor IX, X, XI, XII, thrombin). Furthermore, antithrombin-III binds heparin, which increases the effect of AT-III.
If antithrombin-III is present in reduced amounts in the blood, there is an increased risk of thrombosis.
The procedure
Material needed
- Citrate plasma
Preparation of the patient
- Not necessary
Disruptive factors
- Completely fill the monovette, there should be no coagulation
- The analysis should be done within a few hours (otherwise freeze).
Normal value
| Normal value in mg/dl | 18-34 |
Indications
- Suspicion of increased thrombotic tendency (thrombophilia screening).
Interpretation
Interpretation of increased values
- Cholestasis (bile stasis)
- Inflammation and tumors, unspecified (acute phase protein).
- Therapy with coumarin derivatives (anticoagulants) such as Marcumar (vitamin K deficiency).
Interpretation of lowered values
- Congenital reduction, newborn (due tophysiological vitamin K deficiency).
- Disseminated intravascular coagulation; disseminated intravascular coagulation (DIC syndrome, for short; consumption coagulopathy).
- Liver dysfunction/liver injury, unspecified.
- Protein loss
- Sepsis (blood poisoning)
- Medication
Further notes
- Low AT III → increased risk of thrombosis
- AT III deficiency can reduce or cancel heparin action!
- To confirm the tentative diagnosis, a gene analysis (R506Q) can be performed
