Sign in →

Order Code DRVI2 Dilute Russell's Viper Venom Time (DRVVT) Mix Ratio, Plasma


Ordering Guidance


Because no single coagulation test can identify or exclude all lupus anticoagulants (LA), and because of the complexity of testing LA, one of the following Coagulation Consultation reflexive panel procedures are recommended if clinically indicated:

ALUPP / Lupus Anticoagulant Profile, Plasma

AATHR / Thrombophilia Profile, Plasma and Whole Blood

APROL / Prolonged Clot Time Profile, Plasma



Additional Testing Requirements


Serum anticardiolipin antibody testing (CLPMG / Phospholipid [Cardiolipin] Antibodies, IgG and IgM, Serum) and anti-beta-2 glycoprotein I (B2GMG / Beta-2 Glycoprotein 1 Antibodies, IgG and IgM, Serum) antibody testing should also be performed in conjunction with coagulation-based testing for lupus anticoagulants to enhance detection of different types of antiphospholipid antibodies.



Specimen Required


Only orderable as a reflex. For more information see DRVI1 / Dilute Russell's Viper Venom Time (DRVVT), with Reflex, Plasma.

 

Specimen Type: Platelet-poor plasma

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

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL Platelet poor plasma

Collection Instructions:

1. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.

2. Centrifuge, transfer all plasma into a plastic vial and centrifuge plasma again.

3. Aliquot into a separate plastic vial, leaving 0.25 mL in the bottom of the centrifuged vial.

4. Immediately freeze plasma (no longer than 4 hours after collection) at -20° C or, ideally, -40° C or below.


Useful For

Detecting the presence or helping to exclude the presence of lupus anticoagulants (LAs)

 

Identifying LAs that do not prolong the activated partial thromboplastin time (APTT)

 

Evaluating unexplained prolongation of the APTT or prothrombin time clotting tests

 

Distinguishing LA from a specific coagulation factor inhibitor or coagulation factor deficiencies

Method Name

Only orderable as a reflex. For more information see DRVI1 / Dilute Russell's Viper Venom Time (DRVVT), with Reflex, Plasma.

 

Optical Clot-Based

Reporting Name

DRVVT Mix Ratio

Specimen Type

Plasma Na Cit

Specimen Minimum Volume

Platelet poor plasma: 0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Plasma Na Cit Frozen 14 days

Reference Values

Only orderable as part of a reflex. For more information see DRVI1 / Dilute Russell's Viper Venom Time (DRVVT), with Reflex, Plasma.

 

<1.20

Normal ranges for children: Not clearly established but similar to normal ranges for adults, except for newborn infants whose results may not reach adult values until age 3 to 6 months.

Method Description

The dilute Russell's viper venom time (DRVVT) mix assay is performed on the Instrumentation Laboratory ACL TOP. Patient plasma is mixed in a 1:1 ratio with normal pooled plasma and incubated for a specified time, then combined with a DRVVT screening reagent containing Russell's viper venom, phospholipids, heparin neutralizing agents, calcium, buffers, stabilizers, and sodium azide to trigger the coagulation process. Subsequently, the time to clot formation is measured optically using a wavelength of 671 nm.

 

The patient DRVVT mix clotting time is normalized by dividing the patient result by the mean DRVVT screening clotting time of normal pooled plasma to yield a ratio.(Package insert: CRYOcheck LA Check. Precision BioLogic, Inc; 01/2023)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

85613

LOINC Code Information

Test ID Test Order Name Order LOINC Value
DRVI2 DRVVT Mix Ratio 75512-4

 

Result ID Test Result Name Result LOINC Value
RMRI2 DRVVT Mix Ratio 75512-4