Test Code LAB4075 D-DIMER, QUANTITATIVE
Specimen Type
Blue top tube (buffered 3.2% liquid sodium citrate) filled to the indicator with whole blood or Sodium Citrate Plasma removed from cells.
Specimen Volume
3mL Blue top (3.2% Sodium Citrate), or
5mL Blue top (3.2% Sodium Citrate), or
1mL Blue top (3.2% Sodium Citrate) MiniCollect vial, or
500uL (minimum) Sodium Citrate Plasma spun and removed from cells.
Turnaround Time
STAT: 1 hour
Routine: 4 hours
Test Schedule
Daily
Sample Stability
Room temp: 8 hours, spun or unspun
Frozen samples are stable for 2 weeks at -20C or 12 months at -70C.
Method
Immunoturbidimetric
Reference Ranges
D-Dimer, µg/mL FEU < 0.50
Values of less than or equal to 0.50 µg/mL FEU have a negative predictive value of 98% for VTE (PE and DVT) when the Wells pretest probability is low or moderate. Results of the D-Dimer test should always be interpreted in conjunction with the patient’s medical history and clinical presentation. A very low percentage of patients with DVT may yield results below the cut-off of 0.50 µg/mL FEU Wells,PS; et al. Use a Clinical Model for Safe Management of Patients with Suspected PE.
Synonyms
D-Dimer; Dimer & Crosslinked Fibrin Degradation Product; XDP
CPT Codes
85380
Test Components
D-Dimer, Qnt
Specimen Processing
Centrifuge and test sample within 8 horus. If Testing is >8 hours centrifuge and freeze plasma for up to 2 weeks.
Rejection Criteria
Clotted or improperly filled tubes as well as severely hemolyzed specimens
Test Limitations
Blood/anticoagulant volume is critical.
Clinical Information
The D-dimer test is used to quantitate the amount of D-dimer in a sample. The specific degradation of fibrin , known as fibrinolysis, is the reactive mechanism responding to the formation of fibrin. On the fibrin clot, plasmin degrades fibrin into various products, including D-dimers. Antibodies specific for these products, which do not recognize fibrinogen, have been developed. The presence of these fibrin degradation products, among which D-dimer is the terminal product, confirms that the fibrinolytic system is in action in response to coagulation activation.
The D-dimer acts as a negative predictor for the diagnosis of a thrombotic episode such as deep vein thrombosis (DVT) or pulmonary embolism (PE). Other clinical applications for this test include DIC, efficacy of treatment for a thrombotic episode and screen for possible re-occurrence (myocardial infarction), and to screen for other activation states of coagulation (e.g., post-operative, cancer, and cirrhosis).