| 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 # |
Factor II Activity, Clotting
Message*Take to processing ASAP
Test Code
331
Alias/See Also
LAB303
CPT Codes
85210
Preferred Specimen
1 mL frozen platelet-poor plasma collected in 3.2% sodium citrate (light blue-top) tube
See Coagulation in Specimen Collection and Handling
See Coagulation in Specimen Collection and Handling
Minimum Volume
0.5 mL
Instructions
Please submit a separate, frozen vial for each special coagulation assay ordered. Draw blood in a light blue-top tube containing 3.2% sodium citrate, mix gently by inverting 3-4 times. Centrifuge 15 minutes at 1500 g within one hour 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(s). Freeze immediately and transport on dry ice.
Transport Container
Transport tube
Transport Temperature
Frozen
Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 28 days
Refrigerated: Unacceptable
Frozen: 28 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolysis • Received thawed
Methodology
Photometric Clot Detection
Setup Schedule
Sun, tues, thurs, fri
Report Available
2-6 days
Limitations
Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: decreased, Factor V-no effect; Heparin (UFH or LMWH): no effect (reagent contains heparin neutralizer); Dabigatran or Argatroban (Thrombin Inhibitors): no effect to inhibitor pattern or falsely low; Rivaroxaban or Apixaban (Factor Xa Inhibitors): no effect to inhibitor pattern.
Reference Range
70-150 % normal
Clinical Significance
Factor II Activity, Clotting - The Factor II Activity clotting assay provides a quantitative level of Factor II (also known as Prothrombin) activity. Factor II/Prothrombin is essential for normal hemostasis and deficiencies are associated with increased bleeding risk. As a vitamin K- dependent clotting factor, decreased levels are observed with vitamin K antagonists (eg. warfarin therapy) and vitamin K deficiency. Deficiencies may also occur with hepatic dysfunction or as a result of inhibitor development. Antibodies to prothrombin can occur in patients with anti- phospholipid antibodies and can cause significant clinical bleeding; however, because these antibodies bind to a nonactive portion of the molecule, increased clearance occurs, so that a deficiency rather than an inhibitor is detected. Congenital Factor II deficiency is extremely rare. Anticoagulant interference: if not clinically contraindicated, avoid warfarin therapy for approximately 2 weeks before testing. Direct Xa or thrombin inhibitor therapy may cause falsely low levels (avoid for approximately 2-3 days before testing if not clinically contraindicated.
The Factor II Activity, Clotting assay IS NOT intended to identify the Prothrombin 20210G>A Gene Mutation, which is associated with the increased thrombotic risk.
The Factor II Activity, Clotting assay IS NOT intended to identify the Prothrombin 20210G>A Gene Mutation, which is associated with the increased thrombotic risk.
Performing Laboratory
| Quest Diagnostics Nichols Institute-San Juan Capistrano, CA |
| 33608 Ortega Highway |
| San Juan Capistrano, CA 92675-2042 |