D-dimers
- Description
- D-dimer levels are measured by latex immunoassay which employs latex particles coated with antibodies to D-dimers to capture D-dimers in the test plasma. The D-dimers act as a bridge between latex particles that leads to a degree of agglutination directly proportional to concentration, which is measured turbidimetrically.
- Clinical details
- Progressive degradation of cross-linked fibrin by plasmin leads to formation of small terminal derivates, one of which is D-dimer. Each D-fragment in a D-dimer molecule is derived from a different parent fibrin(ogen) molecule and remain joined due to cross-linking, so detection of D-dimers in plasma indicates the presence of a blood clot. Elevated D-dimers are a marker of reactive fibrinolysis and can be encountered in conditions such as DVT, PE & DIC. A normal D-dimer level has a high negative predictive value for DVT & PE.
- Related condition
- Reference range
D-dimer cut off (mg/L FEU) according to age:
< 60 yrs - <0.5
60 - 69 yrs - <0.6
70 - 79 yrs - <0.7
80 - 89 yrs - <0.8
> 90 yrs - <0.9
- Units
- mg/L FEU
- Testing site
- Synnovis : Blood Sciences : Guy's Hospital|St Thomas' Hospital
- Laboratory
- Diagnostic Haemostasis and Thrombosis
- Sample type and volume required
- External requests: Citrated platelet poor plasma 400µL x 1 aliquot Internal requests: please refer to EPR label
- Special sample instructions
The sample should be analysed within 4 hours of venepuncture. Please ensure sample tubes are filled exactly to the fill-line as underfilling creates a dilution error and leads to inaccurate results
- Turnaround time
- 4 hours
- Contacts
Diagnostic Haemostasis and Thrombosis Department
St Thomas’ Hospital
Phone: 020 7188 2797
St Thomas’ Hospital
North Wing – 4th and 5th Floors
Westminster Bridge Road
London SE1 7EHGuy’s Hospital
Phone: 020 7188 7188 ext. 53860
Guy’s Hospital
Southwark Wing – 4th Floor
Great Maze Pond
London SE1 9RT
Outside core hours, contact Duty Haemostasis Biomedical Scientist