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Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Inherited antithrombin deficiency: a review.
1Department of Internal Medicine, University of Minnesota School of Medicine, Minneapolis, MN, USA.
Summary
Antithrombin (AT) deficiency, a rare inherited condition, increases the risk of venous thromboembolism (VTE). Diagnosis requires functional and antigenic assays after excluding acquired causes, guiding VTE prophylaxis and treatment.
Area of Science:
- Hematology
- Coagulation Science
- Thrombophilia Research
Background:
- Antithrombin (AT) is a critical inhibitor of blood coagulation, primarily inactivating thrombin and factor Xa.
- Inherited AT deficiencies, affecting 1 in 500 to 5000 individuals, are classified as quantitative (Type I) or qualitative (Type II).
- Type II deficiencies include Type IIb (heparin-binding region defect) and Type IIa (thrombin-binding site mutation), with Type IIa being more thrombogenic.
Purpose of the Study:
- To outline the diagnostic approach for antithrombin deficiency in individuals with thrombophilia.
- To discuss the association between AT deficiency and the risk of venous thromboembolism (VTE) and pregnancy loss.
- To present current VTE prophylaxis and treatment guidelines for AT deficiency and address data gaps regarding AT concentrates.
Main Methods:
- Utilizing functional AT activity assays for initial screening in thrombophilic individuals.
- Confirming diagnosis by ruling out acquired causes and repeating AT testing on a separate sample.
- Employing antigenic AT assays to differentiate between Type I and Type II deficiencies, with specialized tests for subclassification.
Main Results:
- AT deficiency is strongly associated with an increased risk of venous thromboembolism (VTE) and pregnancy loss.
- The link between AT deficiency and arterial thrombosis is considered weak.
- Current guidelines for VTE prophylaxis and treatment management exist, but data on AT concentrate usage remains limited.
Conclusions:
- Accurate diagnosis of AT deficiency involves functional and antigenic assays, excluding acquired causes.
- AT deficiency significantly elevates the risk for VTE and adverse pregnancy outcomes.
- Further research is needed to clarify the optimal use of AT concentrates in managing AT deficiency.
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