These results indicate that the TFPI -33T->C and -399C->T polymorphisms are significantly associated with venous thrombosis in the presence of other risk factors, especially APS, and may be clinically relevant in patients who are prone to hypercoagulability.
Coexistence of TFPI and protein C IgG antibodies, regardless of their avidity, was strongly associated with a more severe thrombotic phenotype in APS patients (OR: 20.2, 95%CI: 2.0-47.0, p < 0.0001) and also in thrombotic controls (OR: 75.0, 95%CI 1.2-195, p = 0.02).