| 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 # |
Antithrombin III Activity
Test Code216Q
Quest Code
216
CPT Codes
85300
Preferred Specimen
1 mL frozen platelet-poor plasma collected in 3.2% Sodium citrate (light blue-top) tube
Minimum Volume
0.5 mL
Instructions
Centrifuge light blue-top tube for 15 minutes at approximately 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/mcL). Freeze immediately and ship on dry ice.
Transport Container
Transport tube
Transport Temperature
Frozen
Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days
Refrigerated: Unacceptable
Frozen: 30 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolysis
Methodology
Chromogenic Substrate
Setup Schedule
Tues-sat
Report Available
1-4 days
Limitations
Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: no effect; Heparin (UFH or LMWH): no effect to decrease (UFH may decrease levels physiologically but no assay interference); Dabigatran or Argatroban (Thrombin Inhibitors): may falsely increase; Rivaroxaban or Apixaban (Factor Xa Inhibitors): no effect.
Reference Range
| 1 day-1 month | 41-108 % normal |
| 31 days-2 months | 50-120 % normal |
| 3-5 months | 73-120 % normal |
| ≥6 months | 80-135 % normal |
Clinical Significance
Aids in the detection of hypercoagulable states associated with venous thrombotic episodes. May be useful in patients who appear to be hyporesponsive to heparin.
Performing Laboratory
| Quest Diagnostics Nichols Institute-San Juan Capistrano, CA |
| 33608 Ortega Highway |
| San Juan Capistrano, CA 92675-2042 |
