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LUPUS ANTICOAGULANT PANEL: CPT 4 Code: 85610 (PT); 85730 (APTT); 85613 (DRVVT), 85335 (Inhibitor screen) Test Order Mnemonic: LUPUSPANEL Test Includes: PT, APTT, DRVVT, Inhibitor screen, other tests as needed (call laboratory). Applies To: Detects presence of Lupus Anticoagulant Lab: Hematopathology Request Form: Hematology A Collection: Routine venipuncture; discard 1st mL of blood or collect other tubes (EDTA, red-topped) prior to collecting sample in blue-topped (citrate) tube. Storage Instructions: Viable for 4 hours at room temperature. If time from draw to receipt in the laboratory is to be greater than 4 hours, double centrifuge the specimen; remove the plasma from red cells and snap freeze (-70°C) plasma. Snap frozen plasma is viable indefinitely. Causes for Rejection: 3.8% sodium citrate tueb, QNS, clotted, severely hemolyzed specimen, specimen greater than 4 hours old, identification error, sample processed and/or stored improperly. Availability: Samples are accepted 24 hours per day at Sample Management, 5.136 McCullough Bldg. Turnaround Time: Test performed once per week (batch); maximum 7 day turn around. Call Laboratory for schedule. Special Instructions: Deliver sample to lab within half hour for best results. Specimen: Blood Volume: 4.5 ml Minimum Volume: Call Lab Container: 3.2% sodium citrate tube (light blue-top); [NOTE: 3.8% sodium citrate tubes will NOT be accepted] Reference Range: NEGATIVE Test Method: Electromechanical viscosity detection. See Dilute Russell Viper Venom Test for details on DRVVT. Interfering Substances: Anticoagulant therapy (Heparin > 1 IU/ml, Coumadin) Patients with deficiencies of Factors II, V, or X, or patients on oral anticoagulant therapy (OAT) may exhibit prolonged results. However, the final ratio (DRVVT/DRVVC) should be normal unless LA is present. False positive results have been known to infrequently occur with patient on OAT. It is recommended that testing not be done on patients receiving OAT until having been off coumadin for 2 weeks. Plasma containing heparin levels greater than 1.0 U/ml may give false positive results, and should not be tested with these reagents. In accordance with the SSC Subcommittee for the Standardization of LA guidelines, results should be compared to other established LA tests performed on the same sample, as no single assay can guarantee with certainty that LA is present or absent in test samples. Revised 10/11/07 by W. Russo, MT(ASCP) |
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