Key Takeaways

D-dimer is a plasmin-derived soluble degradation product of cross-linked fibrin.

There are many causes for an elevated D-dimer level, including thrombotic and non-thrombotic conditions, such as:

  • Malignancy
  • Inflammation
  • Infection, including COVID19
  • Pregnancy
  • Liver disease
  • Elderly

D-dimers are most useful:

  • In diagnostic algorithms to exclude a diagnosis of venous thromboembolism (VTE) in those with low clinical probability for this condition.
  • To determine the optimal duration of anticoagulation in VTE patients (especially women).
  • In the diagnostic algorithm for disseminated intravascular coagulation DIC.

Assays include:

  • Whole blood agglutination assays
  • Enzyme-linked immunosorbent assays (ELISA)
  • Enzyme-linked immunofluorescent assays (ELFA)
  • Latex agglutination assays

ELISA, ELFA, and quantitative latex agglutination assays were more sensitive than whole-blood agglutination assays . Therefore, unless other assays are unavailable, the whole-blood D-dimer assay should not be used.

Normal plasma levels of D-dimer by ELISA testing are <500 ng/mL for fibrin equivalent units (FEU) or <250 ng/mL for D-dimer units (DDU).  

 1 / 0