Practical points when testing thrombophilia
| Thrombophilia . | Type of test . | Practical points . |
|---|---|---|
| Inherited thrombophilia | ||
| Factor V Leiden mutation | Activated PC resistance screening testa | Can be influenced by acute thrombosis, high estrogen states (pregnancy, hormone use), coagulation factor deficiencies (eg, FVIII, FIX), the presence of lupus anticoagulant, and anticoagulant use |
| DNA test | Can be tested regardless of use of anticoagulants or hormonal status | |
| Prothrombin G20210A mutation | DNA test | Can be tested regardless of use of anticoagulants or hormonal status |
| PC deficiency | Typically chromogenic, ELISA or functional clotting-based assay | May be influenced by acute thrombosis, high estrogen states (pregnancy, hormone use), and anticoagulant use—interpret abnormal values with caution |
| PS deficiency | ||
| AT deficiency | ||
| Acquired thrombophilia, antiphospholipid antibodiesb | ||
| Lupus anticoagulant | Substantial variation among laboratories; typically includes a screening (eg, dilute Russell viper venom test or lupus anticoagulant-sensitive prothrombin time) and a confirmation test (eg, mixing or correction test) | Consult local laboratory for specifics, is generally influenced by anticoagulant use |
| Anti−ß2-glycoprotein-I IgG and IgM antibodies | Typically ELISA | Substantial variation in absolute cutoff values, consult local laboratory for specifics |
| Anticardiolipin IgG and IgM antibodies | Typically ELISA | Substantial variation in absolute cutoff values, consult local laboratory for specifics |
| Thrombophilia . | Type of test . | Practical points . |
|---|---|---|
| Inherited thrombophilia | ||
| Factor V Leiden mutation | Activated PC resistance screening testa | Can be influenced by acute thrombosis, high estrogen states (pregnancy, hormone use), coagulation factor deficiencies (eg, FVIII, FIX), the presence of lupus anticoagulant, and anticoagulant use |
| DNA test | Can be tested regardless of use of anticoagulants or hormonal status | |
| Prothrombin G20210A mutation | DNA test | Can be tested regardless of use of anticoagulants or hormonal status |
| PC deficiency | Typically chromogenic, ELISA or functional clotting-based assay | May be influenced by acute thrombosis, high estrogen states (pregnancy, hormone use), and anticoagulant use—interpret abnormal values with caution |
| PS deficiency | ||
| AT deficiency | ||
| Acquired thrombophilia, antiphospholipid antibodiesb | ||
| Lupus anticoagulant | Substantial variation among laboratories; typically includes a screening (eg, dilute Russell viper venom test or lupus anticoagulant-sensitive prothrombin time) and a confirmation test (eg, mixing or correction test) | Consult local laboratory for specifics, is generally influenced by anticoagulant use |
| Anti−ß2-glycoprotein-I IgG and IgM antibodies | Typically ELISA | Substantial variation in absolute cutoff values, consult local laboratory for specifics |
| Anticardiolipin IgG and IgM antibodies | Typically ELISA | Substantial variation in absolute cutoff values, consult local laboratory for specifics |
Activated PC resistance testing can be used as a screening test; confirmatory testing is done by DNA testing.
Also refer to guidance from the Scientific and Standardization Committee for lupus anticoagulant/antiphospholipid antibodies of the International Society on Thrombosis and Haemostasis and the 2023 American College of Rheumatology/European Alliance of Associations for Rheumatology Antiphospholipid Syndrome Classification Criteria.42,43
ELISA, enzyme-linked immunosorbent assay; F, factor.