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 CodeCPT Codes
85613, 85730
Includes
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 (x2) frozen platelet-poor plasma
Minimum Volume
1 mL (x2)
Instructions
Transport Container
Plastic screw-cap vial
Transport Temperature
Frozen
Specimen Stability
Room temperature: Unacceptable Refrigerated: Unacceptable Frozen: 90 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Specimens received room temperature or refrigerated • Hemolysis
Methodology
Clot Detection
Setup Schedule
Set up: Mon-Fri (night shift).; Report available: Next day
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
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
Last Updated: February 23, 2012