Dilute Russell's Viper Venom Time (DRVVT) Confirmation Ratio, Plasma
Use
This test is useful for confirming the presence or helping to exclude the presence of lupus anticoagulants (LA). It identifies LA that do not prolong the activated partial thromboplastin time (APTT) and is used for evaluating unexplained prolongation of the APTT or prothrombin time clotting tests. Additionally, the test helps in distinguishing LA from a specific coagulation factor inhibitor or coagulation factor deficiencies.
Special Instructions
The test is only orderable as part of a reflex, specifically associated with DRVI1 / Dilute Russell's Viper Venom Time (DRVVT), with Reflex, Plasma. Additional serum anticardiolipin and anti-beta-2 glycoprotein I antibody testing should also be performed in conjunction to enhance detection of different antiphospholipid antibodies.
Limitations
DRVVT assays ordered as a single, stand-alone test should be interpreted within patient clinical context and require close attention to medication use. The test may not distinguish LA from heparin or inhibitors of factors V or VIII, which can cause false-positive results. False-negative results may occur if residual platelets are present in frozen-thawed plasma. Some LAs may only be detectable by other tests (e.g., Staclot LA).
FDA ApprovedNew York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 50410-0
- 50410-0
Result Turnaround Time
2 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.5 mL
Container
Light-blue top (3.2% sodium citrate); Plastic vial for submission
Collection Instructions
1. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing. 2. Centrifuge, remove plasma, and centrifuge plasma again. 3. Aliquot into a separate plastic vial, leaving 0.25 mL in the bottom of the centrifuged vial. 4. Freeze plasma immediately at -20 degrees C or ideally -40 degrees C or below, not exceeding 4 hours post collection.
Causes for Rejection
Gross hemolysis, Gross lipemia, Gross icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 14 days |