other causes and factors affecting raised D-dimer levels
Last reviewed 01/2021
Other conditions associated with a raised D-dimer include:
- D-dimer
levels are raised in many systemic illnesses associated with fibrin formation
and degradation
- elevated levels of D-dimers occur in most critically ill patients with severe infection, trauma, or inflammatory disorders (1)
- in
addition to venous thromboembolism, raised levels of circulating D-dimers are
detected in patients with:
- disseminated intravascular coagulation
- vaso-occlusive sickle-cell crisis
- acute cerebrovascular accident
- acute myocardial infarction
- unstable angina
- atrial fibrillation
- pneumonia
- vasculitis
- superficial phlebitis
- many cancers including lung, prostate, cervical, and colorectal
- note that only about 20% or less of patients admitted with these conditions will have a baseline D-dimer in the normal range (1)
Other factors affecting D-dimer levels:
- larger clots tend to produce a higher levels of circulating D-dimer
- there is an increase in circulating D-dimer levels with age, pregnancy, and smoking
- D-dimer levels may fail to increase if a patient has an acute venous thromboembolism, but impaired fibrinolytic activity
- D-dimer levels are reduced with initiation of heparin therapy, and may be lowered by two-thirds in patients on oral anticoagulants
- the time interval between
onset of the acute venous thromboembolism and sample collection may affect the
level of D-dimer detected
- there may be normalisation of D-dimer levels with venous thromboembolism of longer than 7 days duration
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