Dilute Russell's Viper Venom Time (DRVVT) Mix, Plasma

Casandra

Casandra Test Code MC85830Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID DRV2CPT Code 85613

Dilute Russell's Viper Venom Time (DRVVT) Mix, Plasma

Clinical Use

Use

The DRVVT Mix test is useful for detecting the presence or helping to exclude lupus anticoagulants (LA), particularly those that do not prolong activated partial thromboplastin time (APTT). It is utilized in evaluating the unexplained prolongation of the APTT or prothrombin time clotting tests and distinguishing LA from specific coagulation factor inhibitors or deficiencies. It confirms abnormal dilute Russell's viper venom time ratios and is part of the reflexive testing for identifying LA.

Special Instructions

This test is not orderable as a standalone test but is part of reflexive testing panels such as the Lupus Anticoagulant Profile or Bleeding Diathesis Profile. Specimen collection instructions include removing as many platelets as possible from plasma before freezing to avoid false negatives. Anticoagulation therapy effects (e.g., warfarin, heparin) may result in false positives, so clinical correlation and repeat testing may be necessary.

Limitations

False positives can occur due to anticoagulation therapy effects. Residual platelets in specimens can decrease sensitivity and specificity, leading to false negatives. The test may not detect all lupus anticoagulants; other tests like Staclot LA or APTT may be needed. LA diagnosis does not have definite predictive value for associated clinical complications. The presence of LA must be confirmed over time (at least 12 weeks) for reliable antiphospholipid syndrome diagnosis.

Test Details

FDA Approved