Test ID: DDI
D-Dimer, Plasma
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
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).(2)
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.(3-6)
Method Name A short description of the method used to perform the test
Immunoassay Turbidimetric
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Specimen Type: Platelet-poor plasma
Collection Container/Tube: Light-blue top (3.2% sodium citrate)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Additional Information: Coagulation testing is highly complex, often requiring the performance of multiple assays and correlation with clinical information. For that reason, we suggest ordering Coagulation Consultations.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross reject |
| Lipemia | Mild OK; Gross reject |
| Icterus | NA |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma Na Cit | Frozen | 30 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Thrombin, the terminal enzyme of the plasma procoagulant cascade, cleaves fibrinopeptides A and B from fibrinogen, generating fibrin monomer. Fibrin monomer contains D domains on each end of the molecule and a central E domain. Most of the fibrin monomers polymerize to form insoluble fibrin, or the fibrin clot, by repetitive end-to-end alignment of the D domains of 2 adjacent molecules in lateral contact with the E domain of a third molecule. The fibrin clot is subsequently stabilized by thrombin-activated factor XIII, which covalently cross-links fibrin monomers by transamidation, including dimerization of the D domains of adjacently polymerized fibrin monomers.
The fibrin clot promotes activation of fibrinolysis by catalyzing the activation of plasminogen (by plasminogen activators) to form plasmin enzyme. Plasmin proteolytically degrades cross-linked fibrin, ultimately producing soluble fibrin degradation products of various sizes that include cross-linked fragments containing neoantigenic D-dimer (DD) epitopes. Plasmin also degrades fibrinogen to form fragments X, Y, D, and E. D-dimer immunoassays use monoclonal antibodies to DD neoantigen and mainly detect cross-linked fibrin degradation products, whereas the fibrino(geno)lytic degradation products X, Y, D, and E and their polymers may be derived from fibrinogen or fibrin. Therefore, the blood content of D-dimer indirectly reflects the generation of thrombin and plasmin, roughly indicating the turnover or activation state of the coupled blood procoagulant and fibrinolytic mechanisms.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
< or =250 ng/mL D-Dimer Units (DDU)
< or =0.5 mcg/mL Fibrinogen Equivalent Units (FEU)
Interpretation Provides information to assist in interpretation of the test results
D-dimer values < or =250 ng/mL D-dimer units (DDU) (< or =0.50 mcg/mL fibrinogen equivalent units [FEU]) are normal. Within the reportable normal range (110-250 ng/mL DDU; 0.22-0.50 mcg/mL FEU), measured values may reflect the activation state of the procoagulant and fibrinolytic systems, but the clinical utility of such quantitation is not established.
A normal D-dimer result (< or =250 ng/mL DDU; < or =0.50 g/mL FEU) has a negative predictive value of approximately 95% for the exclusion of acute pulmonary embolism (PE) or deep vein thrombosis when there is low or moderate pretest PE probability.
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.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Lipemia can interfere with this assay, occasionally causing an under-estimation of the D-dimer level. Therefore, results from lipemic specimens should be interpreted with caution.
The presence of rheumatoid factor at a level >50 IU/mL may lead to an over-estimation of the D-dimer level.
Supportive Data
In Mayo studies examining sensitivity and specificity of D-dimer assays for excluding acute pulmonary embolism (PE) (diagnosed by pulmonary angiography), this automated latex immunoassay method compared well with manual enzyme-linked immunoassays and with a manual latex immunoassay. The negative predictive value of a normal D-dimer by automated latex assay result is approximately 95%, at the 300 ng/mL discriminant level, for excluding acute PE when combined with clinical information (see Interpretation). Clinical correlative evaluation of 98 patients studied for conditions other than acute PE suggests sensitivity approximately 95% and specificity approximately 95% for this method of D-dimer detection in various disease states.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Feinstein DI, Marder VJ, Colman RW: Consumptive thrombohemorrhagic disorders. In Hemostasis and Thrombosis: Basic Principles and Clinical Practice. 4th edition. Edited by RW Colman, J Hirsh, VJ Marder, et al. Philadelphia, PA, JB Lippincott Co., 2001, pp 1197-1234
2. Levi M, ten Cate H: Disseminated intravascular coagulation. N Engl J Med 1999 August;341(8):586-592
3. Brill-Edward P, Lee A: D-dimer testing in the diagnosis of acute venous thromboembolism. Thromb Haemost 1999 August;82(2):688-694
4. 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
5. 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
6. 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
Method Description Describes how the test is performed and provides a method-specific reference
The principle of the test is as follows. When a beam of monochromatic light is allowed to transverse a suspension of microlatex particles to which specific antibodies have been attached by covalent bonding and if the wavelength of the light is much greater than the diameter of the latex particles, the light is only slightly absorbed. In the presenceof the antigen being tested for, the antibody-coated latex particles agglutinate to form aggregates of a diameter greater than the wavelength of the light, more of the latter is absorbed. This increase in light absorption is a function of the antigen level present in the test sample. (Package insert: STA-LIATEST D-DI, Diagnostica Stago, Inc.)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Sunday; Continuously
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
85379
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| DDIRC | Fibrinogen Equivalent Units (FEU) | 48065-7 |
| DDMMC | D-Dimer Units (DDU) | In Process |
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