Evaluation of hypercoagulable states and molecular markers of acute venous thrombosis
Vessel injury, venous stasis, and thrombophilias favor thrombosis. The risk of venous thromboembolism (VTE) increases in proportion to the presence of these predisposing risk factors. Elevated D-dimer is not necessarily a risk factor causing VTE, but it should be used and interpreted as a marker of hypercoagulability. The degree of D-dimer elevation with VTE may depend on the extent of disease, the duration of symptoms, and the use of anticoagulants, with lower D-dimer levels being associated with less extensive disease, longer duration of symptoms, and anticoagulant use. The combination of a genetic thrombophilic defect and one or more acquired risk factor(s), such as surgery or oral contraceptive use, lead to a higher risk of VTE than the separate effects of these single factors. Antibody syndrome is an antibody-mediated hypercoagulable state, defined by the combination of clinical and pathological characteristics as detailed by the Sydney classification.