Prepared By
This procedure is valid for the following chemistry analyzers:
|AU400/AU400e |AU640/AU640e |
|AU480 |AU680 |
|AU600 |AU2700 |
|AU5400 |AU5800 |
|Prepared By |Date Adopted |Supersedes Procedure # |
| | | |
|Review Date |Revision Date |Signature |
| | | |
| | | |
| | | |
| | | |
| | | |
| |# of | |# of |
|Distributed to |Copies |Distributed to |Copies |
| | | | |
| | | | |
| | | | |
| | | | |
PRINCIPLE:1,2,3,4,5
Plasmin degradation of cross-linked fibrin results in the formation of specific degradation products including D-Dimer. As D-Dimer is released into the circulation during the fibrinolytic process, the measurement of D-Dimer and higher molecular weight oligomers containing D-Dimer epitopes is considered to reflect the overall activity of clot formation and lysis. Elevated levels of D-Dimer can occur in a variety of clinical conditions associated with fibrin breakdown, including Deep Vein Thrombosis (DVT), Pulmonary Embolism (PE), and Disseminated Intravascular Coagulation (DIC). D-Dimer is used generally for its negative predictive value.
INTENDED USE:
System reagent for the quantitative determination of D-Dimer in human plasma on Beckman Coulter AU Clinical Chemistry analyzers.
METHODOLOGY:
Immune complexes formed in solution scatter light in proportion to their size, shape and concentration. Turbidimeters measure the reduction of incidence light due to reflection, absorption or scatter.
In this Beckman Coulter AU System procedure, the decrease in intensity of light transmitted (increase in absorbance) through particles suspended in solution is the result of complexes formed during the immunological reaction between D-Dimer in the patient plasma and the anti-human D-Dimer antibodies coated on the latex particles.
SPECIMEN: 6,9,11
Patient Preparation:
None required.
|Additional instructions for patient preparation as designated by this laboratory: |
| |
| |
| |
| |
Type:
Citrated plasma samples, free from hemolysis are the recommended specimens.
Lithium Heparin plasma may also be used. Unlike when using citrated plasma, there is no sample dilution with heparin tubes. Therefore the D-Dimer values in heparin plasma samples are on average 16% higher over the entire measuring range.
|Additional type conditions as designated by this laboratory: |
| |
| |
| |
| |
Handling Conditions:
D-Dimer is stable in citrated or lithium heparin plasma for 4 days when stored at 2 - 8°C or up to 6 months when stored at 200 μg FEU/mL) can generate false low results without appropriate “Z” flags due to excess antigen in the sample. Such situations can occur for patients having lysis therapy.
Samples containing heterophilic antibodies may cause falsely elevated results.
Samples with extremely abnormal optical characteristics, especially turbidity, may produce atypical results.
Interfering Substances:
Results of studies7 show that the following substances interfere with this D-Dimer assay.
The criteria for no significant interference is recovery within 10% of the initial value.
|Bilirubin: |No significant interference up to 40 mg/dL Bilirubin |
|Hemolysis: |No significant interference up to 500 mg/dL Hemolysate |
|Lipemia: |No significant interference up to 700 mg/dL Intralipid* |
|Rheumatoid Factor |No significant interference up to 100 IU/mL |
|Heparin |No significant interference up to 1.5 IU/mL |
* Intralipid, manufactured by KabiVitrium Inc., is a 20% IV fat emulsion used to emulate extremely turbid samples.
Note: In very rare cases of gammopathy, especially monoclonal IgM (Waldenstrom’s macroglobulinemia), may cause unreliable results.
The information presented is based on results from Beckman Coulter AU studies and is current at the date of publication. Beckman Coulter, Inc., makes no representation about the completeness or accuracy of results generated by future studies. For further information on interfering substances, refer to Young6 for a compilation of reported interferences with this test.
|Laboratory specific procedure notes: |
| |
| |
| |
| |
| |
REFERENCES:
1. Budzynski AJ, Marder VJ, Parker ME, Shames P, Brizuela BS, Olexa SA. Antigenic markers of fragment DD, a unique plasmic derivative of human crosslinked fibrin. Blood 1979; 54:794-804.
2. Gaffney PJ, BrasherM. Subunit structure of the plasmin-induced degradation products of crosslinked fibrin. Biochem Biophys Acta. 1973; 295:308-313.
3. Wakai A, Gleeson A, Winter D. Role of D-Dimer Testing in Emergency Medicine. Emerg. Med J. 2003; 20:319-325.
4. Palareti G, Legnani C, Cosmi B, Guazzaloca G, Pancani C, Coccheri S. Risk of veous thromboembolism recurrence: high negative predictive value of D-Dimer performed after oral anticoagulation is stopped. Thromb Haemost 2002; 87:7-12.
5. Wells PS, Anderson DR, Rodger M, Forgie M, Kearon C, Dreyer J, Kovacs G, Mitchell M, Lewandowski B, Kovacs MJ. Evaluation of D-Dimer in the diagnosis of suspected deep vein thrombosis. N Engl J Med. 349; 13.
6. Guder, WG, Ehret W, Heil W, Schmitt Y, Topfer G, Wisser H, Zawta B, et al. Use of anticoagulants in diagnostic laboratory investigations and stability of blood, plasma, and serum samples. WHO/DIL/LAB/99.1 Rev. 2, 2002.
7. CLSI/NCCLS, Interference Testing in Clinical Chemistry. CLSI/NCCLS document EP7-A2, 2004.
8. Young, D.S., Effects of Drugs on Clinical Laboratory Tests, Fifth Edition, AACC Press, 2000.
9. Data on file at Beckman Coulter AU.
10. CLSI/NCCLS of precision performance of clinical chemistry devices; approved guidelines. CLSI/NCCLS document EP5-A2, 2005.
11. Vukovich TC, Hamwi A, Bieglmayer C.D-Dimer testing within the routine clinical chemistry profile. Clinical Chemistry 1998; 44(7):1557-1558.
12. Data is on file for specific AU analyzers.
................
................
In order to avoid copyright disputes, this page is only a partial summary.
To fulfill the demand for quickly locating and searching documents.
It is intelligent file search solution for home and business.