The Dilute Russell's Viper Venom Time (DRVVT) is a laboratory test used to assess the presence of antiphospholipid antibodies, which can lead to thrombosis and pregnancy complications. It matters in clinical practice as a positive result may indicate antiphospholipid syndrome, necessitating anticoagulation therapy to prevent thrombotic events. A key association is with systemic lupus erythematosus, where patients are at increased risk for developing these antibodies and related complications.