Laboratory Testing and the Thrombophilia Workup
Surgeon General's Workshop on Deep Vein Thrombosis
Thomas L. Ortel, M.D., Ph.D.
Duke University Medical Center
8 May 2006
- Useful ancillary data for initial diagnosis (d-dimer).
- Monitoring antithrombotic therapy.
- Evaluation for underlying hypercoagulable state(s).
- Identifies individuals 'at risk' for thrombosis.
- Identifies individuals with an initial thrombosis who are at higher risk for recurrence.
- D-dimer (right arrow) supportive data to help rule out venous thromboembolism.
- Troponins/BNP (right arrow) stratify severity of PE.
- PT, aPTT (right arrow) essential baseline information prior to starting therapy.
- Hypercoagulable workup generally not useful in the acute setting.
- Patients with unexplained, or 'idiopathic' thromboembolism.
- Patients with thromboembolism that is unusually extensive, or in an unusual location (e.g., portal vein thrombosis).
- Patients with a striking family history for venous thromboembolism.
2 pie charts, 1 for Caucasian and 1 for African-American.
- Many studies include children with central venous lines and other acquired disorders.
- Elevated factor VIII and D-dimer is also associated with recurrent thrombosis
Age: neonate to 18 yrs
Line chart showing Impact of thrombophilic disorders on recurrent thromboembolism
2.1.4. For patients with first episode DVT and:
- Antiphospholipid antibodies;
- 2 or more thrombophilic conditions;
- (right arrow) therapy for 12 months (1C+) or indefinite (2C).
2.1.5. For patients with first episode DVT and:
- Antithrombin, protein C or protein S deficiency;
- Factor V Leiden or prothrombin G20210A;
- Elevated homocysteine or factor VIII levels
- (right arrow) therapy for 6-12 months (1A) or indefinite (2C).
|Natural anticoagulants (antithrombin, protein C, protein S):||$450-750|
|Genetic tests (factor V Leiden, prothrombin G20210A):||$600|
|Other (factor VIII, homocysteine):||$200|
* Duke Coagulation Laboratory
- Individuals who test positive for a thrombophilic risk factor require counseling as to:
- risks of thrombosis to themselves and their family members.
- importance of early recognition of signs and symptoms of venous thromboembolism.
- risks and benefits of thromboprophylaxis in high-risk situations.
- Screening of asymptomatic individuals, whether family members of a patient with thrombosis, or in a situation that places them at increased risk for thrombosis, is generally not recommended.
- However, in selected situations, knowledge of a specific thrombophilic state might guide therapeutic decision-making (e.g., decision concerning HRT usage).
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- Prospective clinical studies to define:
- Role, if any, of screening asymptomatic family members or individuals in high-risk situations.
- Impact on optimal therapy for patients with venous thrombosis and thrombophilia.
- Better education for providers as well as consumers concerning risk factors, prevention strategies, need for genetic counseling, etc.