Test Code LAB3210 Lupus Anticoagulant Panel with Reflexes
Methodology
Absorbance measurement, clot signature formation
Testing Algorithm:
If either Screening test is abnormal, then the DRVVT 50:50 mix, DRVVT confirmation, SCT 50:50 mix, and/or SCT confirmation may be performed at an additional charge.
Literature References:
1. Eby C. Antiphospholipid syndrome review. Clin Lab Med 2009;Jun;29(2):305-19.
2. Pengo V, et al. Update of the guidelines for lupus anticoagulant detection. Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibody of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis. J Thromb Haemost 2009;Oct;7(10):1737-40.
Performing Laboratory
Barnes-Jewish Hospital Laboratory
Specimen Requirements
Specimen Type: Plasma
Container/Tube: Light-blue top (citrate)
Specimen Volume: 2 Full tubes
Specimen Minimum Volume: 2 Full tubes
Collection Instructions:
- Draw a discard blue top tube prior to drawing a light-blue top (citrated) tube if using a Winged Infusion Set. Discard tube should be under filled and discarded.
- Clotted blood or an insufficient specimen is not acceptable.
- Avoid phlebotomy techniques which cause hemolysis and heparin contamination.
- Follow nursing policy on volume of blood to discard prior to collecting blood from indwelling heparinized catheters.
Analyte Stability:
4 hours at 18° C to 24° C
Platelet-free plasma can be frozen at -20 for transport on dry ice up to 72 hours
or stored 6 months at -70° C.
Additional Information: If the patient is a hospital patient and the hematocrit is >55%, call Barnes-Jewish Hematology Laboratory at 314-362-5203 for instructions.
Specimen Transport Temperature
Ambient Yes/Refrigerate NO/Frozen Yes
Reference Values
Normal= dRVVT Screen ratio </= 1.20, Silica Clotting Time (SCT) ratio </= 1.16
Additional test as appropriate:
dRVVT Confirm ratio = </= 1.20
dRVVT Screen/Confirm ratio = Normal = </= 1.20
dRVVT 50:50 ratio, Normal = </= 1.20
SCT Confirm ratio = </= 1.16
SCT Screen/Confirm ratio = Normal = </= 1.16
SCT 50:50 ratio, Normal = </= 1.16
Literature Reference:
1. Eby C. Antiphospholipid syndrome review. Clin Lab Med 2009;Jun;29(2):305-19.
2. Giannakopoulos B, Passam F, Loannau Y, Krilis SA. How we diagnose the antiphospholipid syndrome. Blood 2009;Jan 29;113(5):985-94.
Day(s) Test Set Up
Monday, Wednesday, Friday
Cut-off time: 0800
Turnaround Time:
STAT: not available
Routine: results available the day of testing
Test Classification and CPT Coding
85670 – Thrombin Time
85613 – Russell viper venom time, diluted, screen
85732 - Silica clotting time, screen
If appropriate:
85613 – Russell viper venom time, diluted, 50:50 mix
85613 - Russell viper venom time, diluted, confirmation
85732 - Silica clotting time, 50:50 mix
85732 - Silica clotting time, confirmation
Additional Information
For BJH Laboratory Use Only
Analyte Stability:
4 hours at 18° C to 24° C
Platelet-free plasma can be frozen at -20 for transport on dry ice up to 72 hours
or stored 6 months at -70° C.
Laboratory Processing Instructions:
Test performed in BJH Core Lab.
LOINC Code Information
Name | LOINC Code |
DRVVT 50/50 Ratio | 75513-2 |
DRVVT Confirmation/Screen Ratio | 50410-0 |
Interpretation | 75514-0 |
SCT screen/confirmation ratio | 66736-0 |
Thrombin Time | 3243-3 |