| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
D-DIMER
MessageCoagulation
Test Code
LAB313
Alias/See Also
Dimer, DD
CPT Codes
85379
Preferred Specimen
Blue top 3.2% citrated tube, plasma
Note: Do NOT place blue top tube on ice
Note: Do NOT place blue top tube on ice
Minimum Volume
2.7 mL whole blood filled to the designated line on specimen container (blue top tube, citrate)
Other Acceptable Specimens
1.8mL Low Volume blue top tube, citrated (microtainer)
Instructions
LAB: Centrifuge in validated Platelet Poor Plasma Centrifuge for 2 minutes at 7200 rpm. Specimen to be delivered to Coagulation department STAT. Notify CLS upon arrival.
**Testing must be completed within 4 hours of collection.
Note: If unable to deliver whole blood to testing laboratory within stability time, platelet poor plasma should be aliquoted and placed in freezer. Centrifuge light blue-top for 2 minutes at 7200 rpm (STAT Coag centrifuge) 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 aliquoted plasma a second time and transfer platelet-poor plasma into a new plastic vial and place in 2 – 8℃ refrigerator or freeze -20℃ if delay longer than 1 hour. Once thawed, specimen must be tested within 2 hours.
Freeze aliquot at -20℃ for at least 1 hour when sending to alternate campus for testing.
**Testing must be completed within 4 hours of collection.
Note: If unable to deliver whole blood to testing laboratory within stability time, platelet poor plasma should be aliquoted and placed in freezer. Centrifuge light blue-top for 2 minutes at 7200 rpm (STAT Coag centrifuge) 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 aliquoted plasma a second time and transfer platelet-poor plasma into a new plastic vial and place in 2 – 8℃ refrigerator or freeze -20℃ if delay longer than 1 hour. Once thawed, specimen must be tested within 2 hours.
Freeze aliquot at -20℃ for at least 1 hour when sending to alternate campus for testing.
Transport Container
Ambient: whole blood 4 hours
Frozen (-20℃): plasma frozen for at least 1 – 2 hours
Frozen (-20℃): plasma frozen for at least 1 – 2 hours
Transport Temperature
Processed Platelet Poor Plasma:
Room Temp – 4 hours
Refrigerated – 4 hours
Frozen – 2 weeks
Room Temp – 4 hours
Refrigerated – 4 hours
Frozen – 2 weeks
Specimen Stability
Whole Blood: Ambient 4 hours
Processed Platelet Poor Plasma:
Processed Platelet Poor Plasma:
| Room Temp (15-25° C) | 4 hours |
| Refrigerated (2-8°C) | 4 hours |
| Frozen (-20°C) | 2 weeks |
| Frozen (-70°C or colder) | 6 months |
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
| Hemolyzed, clotted specimen, contaminated, underfilled - QNS, overfilled tube, whole blood specimen transported on ice |
Methodology
Coagulation activation results in the cleavage of fibrinogen to fibrin monomer. The fibrin monomers spontaneously aggregate to fibrin and are cross-linked by Factor XIII, producing a fibrin clot. In response to the coagulation process the fibrinolytic system is activated resulting in the conversion of plasminogen into plasmin, which cleaves fibrin (and fibrinogen) into the fragments D and E. Due to the cross-linkages between the D-domains in the fibrin clot, the action of plasmin releases fibrin degradation products with cross-linked D-domains. The smallest unit is the D-Dimer. Detection of D-Dimers, which specifies cross-linked fibrin degradation products generated by reactive fibrinolysis, is an indicator of coagulation activity.
The Latex Reagent is a suspension of polystyrene latex particles of uniform size coated with the F(ab')2 fragment of a monoclonal antibody highly specific for the D-Dimer domain included in fibrin soluble derivatives. The use of the F(ab')2 fragment allows a more specific D-Dimer detection avoiding the interference of some endogenous factors like the Rheumatoid Factor. When plasma, which contains D-Dimer, is mixed with the Latex Reagent and the Reaction Buffer included in the D-Dimer HS 500 kit, the coated latex particles agglutinate. The degree of agglutination is directly proportional to the concentration of D-Dimer in the sample and is determined by measuring the decrease of the transmitted light caused by the aggregates (turbidimetric immunoassay).
FDA Status
Cleared
Report Available
Same Day
Limitations
Hemoglobin up to 500 mg/dL
Bilirubin up to 18 mg/dL
Triglycerides up to 1,327 mg/dL
Rheumatoid Factor up to 1,400 IU/mL
Bilirubin up to 18 mg/dL
Triglycerides up to 1,327 mg/dL
Rheumatoid Factor up to 1,400 IU/mL
Reference Range
215 - 500 ng/mL FEU
Clinical Significance
Elevated D-dimer levels are observed in all diseases and conditions with increased coagulation activation, e.g. thromboembolic disease, disseminated intravascular coagulopathy (DIC), acute aortic dissection, myocardial infarction, malignant diseases, obstetrical complications, third trimester of pregnancy, surgery or polytrauma.
The relevance of the D-Dimer assay is as an aid in the diagnosis of thromboembolic events. Elevated concentrations of D-Dimer are indicative of the presence of a clot and have been reported in deep vein thrombosis, pulmonary embolism and disseminated intravascular coagulation.
At the established clinical cutoff of 500 ng/mL FEU, interpretation of the D-Dimer result must be made in conjunction with the patient’s clinical pre-test probability score to either exclude DVT/PE or indicate that additional studies may be warranted. An elevated D-Dimer does not necessarily indicate the presence of a clot and may be seen in other conditions in which fibrin is formed and broken down or not cleared such as surgery, trauma, infection, liver disease, etc.
The relevance of the D-Dimer assay is as an aid in the diagnosis of thromboembolic events. Elevated concentrations of D-Dimer are indicative of the presence of a clot and have been reported in deep vein thrombosis, pulmonary embolism and disseminated intravascular coagulation.
At the established clinical cutoff of 500 ng/mL FEU, interpretation of the D-Dimer result must be made in conjunction with the patient’s clinical pre-test probability score to either exclude DVT/PE or indicate that additional studies may be warranted. An elevated D-Dimer does not necessarily indicate the presence of a clot and may be seen in other conditions in which fibrin is formed and broken down or not cleared such as surgery, trauma, infection, liver disease, etc.
Performing Laboratory
HHN/HHI
