Dilute Russell's Viper Venom Time (DRVVT) Mix Ratio, Plasma
Use
This test is useful for detecting 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 evaluates unexplained prolongation of the APTT or prothrombin time clotting tests. Additionally, it helps distinguish LA from a specific coagulation factor inhibitor or coagulation factor deficiencies. The test uses the dilute Russell's viper venom time (DRVVT) mix assay to measure clotting time, aiding in the diagnosis or exclusion of LA.
Special Instructions
The test is not orderable as a standalone and is only available as part of a reflex testing panel. It involves the mixing of patient plasma with normal pooled plasma and freeze submission of platelet-poor plasma within specific temperature conditions. Ensure plasma is centrifuged, and follow coagulation handling guidelines closely to avoid false results.
Limitations
The test has a sensitivity of approximately 65% to 70% for detecting lupus anticoagulants (LA), with a specificity of 95% or higher. There is potential for false positives in patients on anticoagulants. Residual platelets in frozen plasma can lead to reduced sensitivity and specificity, potentially causing false negatives. The test might not detect all LA, and some LA may only be detectable by other tests.
FDA ApprovedNew York Approved
Methodology
Automated Analyzer (Coagulation)
Biomarkers
LOINC Codes
- 75512-4
- 75512-4
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)
Collection Instructions
Centrifuge, remove plasma, centrifuge plasma again, aliquot into separate plastic vial, freeze immediately.
Storage Instructions
Freeze plasma at -20 degrees C or ideally -40 degrees C or below within 4 hours of collection.
Causes for Rejection
Specimen not properly frozen or not centrifuged twice to remove platelets.
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 14 days |