[Clinical use of D-dimer testing]

Abstract

D-dimers are fibrin degradation products which are released during local or systemic activation of coagulation. D-dimer testing is widely used for the work-up of patients suspected of deep vein thrombosis or pulmonary embolism. Interpretation of D-dimer levels must take into account the sensitivity and specificity of the assay. The specificity is usually low, and increased D-dimer levels are encountered in many non-thrombotic situations. The sensitivity varies among the different testing methods and is maximal with ELISA assays. Highly sensitive assays allow exclusion of venous thromboembolism when D-dimer levels are normal, without further imaging. However, this diagnostic strategy may only be used safely when the clinical probability of thromboembolism is low to moderate. When combined with other tests of coagulation, D-dimer testing is also useful in the diagnosis of disseminated intravascular coagulation.