Dilute Russell Viper Venom Time Confirmation reported as a Ratio as part of the Lupus Anticoagulant Panel. In the confirmatory assay, a second dRVVT is performed using a reagent with additional phospholipids capable of neutralizing the LA. A ratio of the clotting times is calculated from the dRVVT screening test divided by the dRVVT confirmatory test. If a LA is present, the dRVVT confirmatory test will correct to normal. The dRVVT confirmatory reagent also contains a neutralizing agent for heparin in concentrations up to 1 unit/mL. Although patients on Coumadin or patients with deficiencies of factor II, V, and X may show prolonged times, the final ratio will be normal unless a LA is present. The dRVVT confirmatory assay should be run only if the dRVVT screening assay is elevated above the normal reference interval. In thei case, the confirmatory test is done and a ratio is calculated. If the ratio is greater than the upper limit of the established normal reference interval, the LA is present. If the ratio is less than or equal to the upper limit, the LA is absent. The dRVVT screen to confirm ratio formula is based on the 2009 International Society on Thrombosis and Haemostasis lupus anticoagulant testing guidelines. [PMID:19624461]
status
ACTIVE
Fully-Specified Name
component
Coagulation dilute Russell viper venom induced/Coagulation dilute Russell viper venom induced.excess phospholipid
property
Ratio
time
Pt = Point in time: To identify measures at a point in time. This is a synonym for “spot” or “random” as applied to urine measurements.
system
PPP = Platelet poor plasma
scale
Qn = Quantitative: The result of the test is a numeric value that relates to a continuous numeric scale. Reported either as an integer, a ratio, a real number, or a range. The test result value may optionally contain a relational operator from the set {<=, <, >, >=}. Valid values for a quantitative test are of the form "7", "-7", "7.4", "-7.4", "7.8912", "0.125", "<10", "<10.15", ">12000", 1-10, 1:256
method
Coag = Coagulation Assay: To distinguish coagulation assays based on clotting methods that test function/activity from Immune methods that detect the presence of clotting factors and may or may not be functional assays.