We had near-100% agreement on our May 2022 Quick Question, which attracted 45 voters: “What assay should be deleted from the thrombosis risk factor profile?” Here are our selections:
- Protein C 0%
- Protein S 2% [1]
- Antithrombin 2% [1]
- Activated protein C resistance 7% [3]
- Prothrombin G20210A mutation 4% [2]
- Methylenetetrahydrofolate reductase resistance [MTHFR] polymorphism 85% [38]
Thrombosis risk testing has been available to us since von Kaulla first described “antithrombin 3” deficiency in 1972 using the “serum antithrombin” test. It gained momentum when Dahlbach described activated protein C resistance in 1994, and thrombosis risk testing profiles are now ordered routinely, often without patient indications. A typical thrombosis risk factor profile includes proteins C and S, antithrombin, and activated protein C resistance, which may indicate the factor V Leiden mutation. Many include the prothrombin G20210A mutation, though its detection requires a molecular diagnostic assay. We once included the MTHFR G677T polymorphism, which also requires a molecular assay. While the MTHFR polymorphism has been associated with mild hyperhomocysteinemia, the link between the polymorphism and thrombosis. is weak, as indicated in the attached article.
Hello, Ms. Sneeden. There is little to be gained from an inpatient factor VIII assay when it is part of a thrombosis risk profile, as factor VIII is an acute phase reactant and is likely to be elevated during acute inflammation, which we can assume is present in most inpatients. Many facilities include factor VIII in their outpatient thrombosis risk profile, and a chronically elevated factor VIII can predict thrombosis, however even in an outpatient, there is the likelihood that the elevation is in response to acute infllamation.
Our in-patient Thrombosis profile includes a Factor VIII. They are always elevated. What diagnostic/treatment information is gained by measuring FVIII in an acute situation?