50410-0

LOINC code 50410-0 identifies "dRVVT/dRVVT W excess phospholipid (screen to confirm ratio)". 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]

This code measures Coagulation dilute Russell viper venom induced/Coagulation dilute Russell viper venom induced.excess phospholipid in PPP. It belongs to the COAG class in the LOINC classification.

LOINC (Logical Observation Identifiers Names and Codes) is a universal standard for identifying laboratory and clinical observations. It is maintained by the Regenstrief Institute and used worldwide for health data exchange.