Thrombophilia screen

 

Alternative names, keywords

Antithrombin activity,  lupus anticoagulant, protein C, protein S, Factor V Leiden PCR, prothrombin G20210 gene mutation PCR.

Samples required

4x trisodium citrate blood (blue cap, 3.5 mL tube) taken with minimal stasis, filled to the line, and

Clotted blood (gold cap, 5 mL tube), and

EDTA blood (purple cap, 4 mL tube).

Smaller tubes are available for paediatric samples.

Samples must be analysed or processed in the laboratory within 2 hours of venepuncture. Ideally patients should attend phlebotomy at the hospital to facilitate this.

Best done 4 weeks after stopping warfarin, not at presentation or in non-steady state.

Test indications

BSUH guidelines suggest screen including FBC, coagulation screen, thrombophilia screen including Factor V Leiden and prothrombin gene mutation, cardiolipin antibody & beta-2 glycoprotein-1 antibody is carried out on patients less than 45 years of age who have an episode of venous thromboembolism.

Requests for individual tests (i.e. not as part of screen) should be discussed with the laboratory before submitting sample.

Reference range

Antithrombin activity

84 - 119%

Lupus anticoagulant

See separate page.

Protein C

72 - 136%

Free Protein S

male: 69 - 138%

female: 57 - 124%

Factor V Leiden and prothrombin gene mutation

See separate page.

Source: locally determined.

Turnaround time

1 month

Enquiries

Haematology (Coagulation)