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Test Code DDITT D-Dimer, Plasma

Secondary ID

40936

Useful For

Excluding the diagnosis of acute pulmonary embolism or deep vein thrombosis, particularly when results of a sensitive D-dimer assay are combined with clinical information, including pretest disease probability(1-4)

 

Diagnosis of intravascular coagulation and fibrinolysis, also known as disseminated intravascular coagulation, especially when combined with clinical information and other laboratory test data (eg, platelet count, assays of clottable fibrinogen and soluble fibrin monomer complex, and clotting time assays-prothrombin time and activated partial thromboplastin time)(5)

Method Name

Immunoassay Turbidimetric

Reporting Name

D-Dimer, P

Specimen Type

Plasma Na Cit


Specimen Required


Specimen Type: Platelet-poor plasma

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Spin down, remove plasma and spin plasma again.

Additional Information: Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Plasma Na Cit Frozen (preferred) 90 days
  Ambient  4 hours

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

Mild OK; Gross OK

Icterus

Mild OK; Gross OK

Other

NA

Clinical Information

The specific degradation of fibrin (ie, fibrinolysis) is the reactive mechanism responding to the formation of fibrin. Plasmin is the fibrinolytic enzyme derived from inactive plasminogen. Plasminogen is converted into plasmin by plasminogen activators. The main plasminogen activators are tissue plasminogen activator (tPA) and pro-urokinase, which is activated into urokinase (UK) by, among others, the contact system of coagulation.

 

In the bloodstream, plasmin is rapidly and specifically neutralized by alpha 2-antiplasmin, thereby restricting its fibrinogenolytic activity and localizes the fibrinolysis on the fibrin clot. On the fibrin clot, plasmin degrades fibrin into various products (ie, D-dimers). Antibodies specific for these products, which do not recognize fibrinogen, have been developed. The presence of these various fibrin degradation products, among which D-dimer is the terminal product, is the proof that the fibrinolytic system is in action in response to coagulation activation.

 

Elevated D-dimer levels are found in association with disseminated intravascular coagulation (DIC), pulmonary embolism (PE), deep vein thrombosis (DVT), trauma, and bleeding. D-dimer may also be increased in association with pregnancy, liver disease, malignancy, inflammation, or a chronic hypercoagulable state.

Reference Values

≤500 ng/mL Fibrinogen Equivalent Units (FEU)

D-dimer values ≤500 ng/mL FEU may be used in conjunction with clinical pretest probability to exclude deep vein thrombosis (DVT) and pulmonary embolism (PE).

Interpretation

A normal D-dimer result less than or equal to 500 ng/mL fibrinogen equivalent units (FEU) on the IL D-Dimer HS500 kit has a negative predictive value of approximately 100% (range 97%-100%) and is FDA approved for the exclusion of acute pulmonary embolism (PE) and deep vein thrombosis (DVT) when there is low or moderate pretest probability for PE or DVT.

 

D-dimer concentrations increase with age and, thus, the specificity for DVT and PE exclusion decreases with age. For DVT or PE exclusion, in addition to clinical pretest probability, age-adjusted D-dimer cutoffs are suggested for patients more than 50 years of age.

 

Recent evidence suggests using clinical pretest probability and age-adjusted cutoffs to improve the performance of D-dimer testing in patients greater than 50 years of age. In recent studies, when compared to a fixed D-dimer cutoff, age adjusted D-dimer cutoff values (calculated as follows: age [years] x 10 ng/mL) resulted in equivalent outcomes and no additional false negative findings.(7-8)

 

Increased D-dimer values are abnormal but do not indicate a specific disease state. D-dimer values may be increased as a result of:

-Clinical or subclinical disseminated intravascular coagulation/intravascular coagulation and fibrinolysis

-Other conditions associated with increased activation of the procoagulant and fibrinolytic mechanisms such as recent surgery, active or recent bleeding, hematomas, trauma, or thromboembolism

-Association with pregnancy, liver disease, inflammation, malignancy, or hypercoagulable (procoagulant) states

 

The degree of D-dimer increase does not definitely correlate with the clinical severity of associated disease states.

Clinical Reference

1. Brill-Edward P, Lee A: D-dimer testing in the diagnosis of acute venous thromboembolism. Thromb Haemost 1999 August;82(2):688-694

2. Heit JA, Minor TA, Andrews JC, et al: Determinants of plasma fibrin D-dimer sensitivity for acute pulmonary embolism as defined by pulmonary angiography. Arch Pathol Lab Med 1999 March;123(3):235-240

3. Heit JA, Meyers BJ, Plumhoff EA, et al: Operating characteristics of automated latex immunoassay tests in the diagnosis of angiographically-defined acute pulmonary embolism. Thromb Haemost 2000 June;83(6):970

4. Bates SM, Grand'Maison A, Johnston M, et al: A latex D-dimer reliably excludes venous thromboembolism. Arch Intern Med 2001 February;161(3):447-453

5. Levi M, ten Cate H: Disseminated intravascular coagulation. N Engl J Med 1999 August;341(8):586-592

6. Feinstein DI, Marder VJ, Colman RW: Consumptive thrombohemorrhagic disorders. In Hemostasis and Thrombosis: Basic Principles and Clinical Practice. Third edition. Edited by RW Colman, J Hirsh, VJ Marder, et al. Philadelphia, PA, JB Lippincott Co., 2001, pp 1197-1234

7. Righini M, Van Es J, Den Exter PL, et al: Age-Adjusted D-Dimer Cutoff Levels to Rule Out Pulmonary Embolism: The ADJUST-PE Study. JAMA 2014;311(11):1117-1124. doi:10.1001/jama.2014.2135

8. Schouten HJ, Geersing GJ, Koek HL, et al: Diagnostic accuracy of conventional or age adjusted D-dimer cut-off values in older patients with suspected venous thromboembolism: systematic review and meta-analysis. BMJ 2013;346:f2492

Day(s) and Time(s) Performed

Monday through Sunday; Continuously

Analytic Time

Same day/1 day

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

85379

LOINC Code Information

Test ID Test Order Name Order LOINC Value
DDITT D-Dimer, P In Process

 

Result ID Test Result Name Result LOINC Value
DDITT D-Dimer, P In Process