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D-Dimer, Quantitative
Test Code8659
CPT Codes
85379
Preferred Specimen
1 mL frozen plasma collected in 3.2% sodium citrate (light blue-top) tube
Minimum Volume
0.5 mL
Instructions
Platelet-poor plasma: Centrifuge light blue-top tube for 15 minutes at approximately 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/µL). Freeze immediately and ship on dry ice.
Transport Temperature
Frozen
Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days
Refrigerated: Unacceptable
Frozen: 30 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Grossly lipemic • Clotted specimen • Improper blood to citrate ratio • Plasma received room temperature • Plasma received refrigerated
Methodology
Immunoturbidimetric
Setup Schedule
P.M. Sets up 6 days a week.
Limitations
In patients with low or moderate probability of clots in the deep veins of the leg, a negative D-Dimer result generally rules out DVT. Some patients with blood clots will be false-negatives. This is most common among older patients, those who have undergone prolonged hospitalization, and those with markedly elevated C-reactive protein levels.
Clinical Significance
D-Dimer is one of the measurable by-products of activation of the fibrinolytic system. Quantitation of D-Dimer assesses fibrinolytic activation and intravascular thrombosis. D-Dimer is of particular value in excluding the diagnosis of venous thromboembolism among patients at high risk.
