D-Dimer

Overview

D-dimer is a degradation product of cross-linked fibrin, and its measurement
reflects ongoing activation of the coagulation and fibrinolytic systems. It
becomes elevated when fibrin clots are formed and subsequently broken down,
such as in venous thromboembolism (VTE) or disseminated intravascular
coagulation (DIC). High levels are nonspecific but may indicate thrombosis,
DIC, recent surgery, trauma, infection, or malignancy, whereas low or
undetectable levels help exclude acute thromboembolic disease in low- to
intermediate-risk patients. Clinically, D-dimer is most useful as a rule-out
test for deep vein thrombosis (DVT) and pulmonary embolism (PE) when combined
with pretest probability scoring.clevelandclinic+2

Clinical Use Cases

  • Excluding acute DVT or PE in patients with low or intermediate clinical
    probability.
  • Supporting diagnosis and monitoring of disseminated intravascular
    coagulation.
  • Evaluating suspected venous thromboembolism in pregnancy or postoperative
    settings (with adjusted cutoffs).
  • Assessing risk or activity of thrombosis in certain cardiovascular and
    inflammatory conditions.ncbi.nlm.nih+2

Specimen Types

  • Platelet-poor plasma (citrate anticoagulant).
  • Whole blood (for some qualitative point-of-care assays).

Measurement Methods

  • Quantitative immunoturbidimetric assays.
  • Enzyme-linked immunosorbent assay (ELISA), including high-sensitivity
    formats.
  • Latex agglutination or latex-enhanced turbidimetric assays.
  • Qualitative or semi-quantitative point-of-care immunoassays.academic.oup+3

Test Preparation and Influencing Factors

  • No fasting or special preparation required.
  • Recent surgery, trauma, infection, inflammation, liver disease, malignancy,
    pregnancy, and advanced age can elevate D-dimer, reducing specificity.
  • Anticoagulant therapy may lower levels or modify kinetics after an acute
    thrombotic event.
  • Improper collection, delayed processing, or underfilled citrate tubes can
    affect results.acutecaretesting+3

Synonyms

  • Fibrin degradation products (FDPs) – D-dimer component.
  • Fibrin D-dimer.
  • D-dimer assay.

Further Reading

  • D-Dimer Test – MedlinePlus; U.S. National Library of Medicine;