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| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Lupus Anticoagulant Evaluation with Reflex
Test CodeLUPAP (Quest 7079X)
Includes
PTT-LA and dRVVT with Reflex Confirmations
If PTT-LA Screen is prolonged (>40 seconds), then Hexagonal Phase Confirmation will be performed at an additional charge (CPT code(s): 85598).
If Hexagonal Phase Confirmation is positive or weakly positive, then Thrombin Clotting Time will be performed at an additional charge (CPT code(s): 85670).
If dRVVT Screen is prolonged (>45 seconds), then dRVVT Confirm will be performed at an additional charge (CPT code(s): 85597).
If dRVVT Confirm is positive, then dRVVT 1:1 Mixing Study will be performed at an additional charge (CPT code(s): 85613).
If PTT-LA Screen is prolonged (>40 seconds), then Hexagonal Phase Confirmation will be performed at an additional charge (CPT code(s): 85598).
If Hexagonal Phase Confirmation is positive or weakly positive, then Thrombin Clotting Time will be performed at an additional charge (CPT code(s): 85670).
If dRVVT Screen is prolonged (>45 seconds), then dRVVT Confirm will be performed at an additional charge (CPT code(s): 85597).
If dRVVT Confirm is positive, then dRVVT 1:1 Mixing Study will be performed at an additional charge (CPT code(s): 85613).
Preferred Specimen
1.5 mL frozen platelet-poor plasma (x2) collected in separate 3.2% sodium citrate (light blue-top) tubes
Minimum Volume
1 mL (x2)
Instructions
Separate plasma from cells within 1 hour of collection and freeze IMMEDIATELY. 1 tube = 1ml (0.5min) 2nd tube = 2ml (1.0min) It is important to minimize platelet contamination in the plasma. Platelet membranes may neutralize Lupus Anticoagulants and lead to a false negative result.
Transport Container
Plastic vial(s)
Transport Temperature
Frozen: 90 days
Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days
Refrigerated: Unacceptable
Frozen: 30 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolysis • Received thawed
Methodology
Clot detection
Setup Schedule
Set up: Mon-Fri; Report available: 1-4 days
Limitations
Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: no effect (panel includes mixing studies which correct for Warfarin-induced factor deficiencies); Heparin (UFH or LMWH): possible to misclassify as LA; Dabigatran or Argatroban (Thrombin Inhibitors): panel includes Thrombin Time (TT) which detects thrombin inhibitors, unable to detect if TT significantly abnormal; Rivaroxaban or Apixaban (Factor Xa Inhibitors): possible to misclassify as LA.
Reference Range
| Lupus Anticoagulant | Not detected |
| PTT-LA Screen | ≤40 sec |
| dRVVT Screen | ≤45 sec |
Clinical Significance
Lupus anticoagulants (LA) are members of a family of antibodies with phospholipid-protein specificity. LA may be defined as an immunoglobulin, IgG or IgM or a mixture of both, that interferes with one or more of the in-vitro phospholipid (PL) dependent tests of coagulation. These antibodies are not associated with a hemorrhagic diathesis, but rather have been linked to thrombotic events. In addition to thrombosis other clinical complications have been associated with the presence of LA. These include strokes, nonbacterial thrombotic endocarditis, livedo reticularis and a variety of obstetrical complications such as intrauterine fetal death, recurrent spontaneous abortion, fetal growth retardation, early onset preeclampsia and chorea gravidarum.
Note: Target specific anticoagulant therapy (anti-Xa medications, direct thrombin inhibitors) may cause false positive results.
Note: Target specific anticoagulant therapy (anti-Xa medications, direct thrombin inhibitors) may cause false positive results.
Performing Laboratory
| Quest Diagnostics Nichols Institute |
| 14225 Newbrook Drive |
| Chantilly, VA 20153 |
