APC Resistance
Also known as: APC RST
Use
This test is used as an initial screening to detect activated protein C resistance, which is often due to a factor V Leiden variant. It is important to identify this resistance as it poses a risk for thrombophilia. The preferred confirmatory test is the Factor V Leiden DNA test, especially in cases with extreme factor V deficiency or presence of anticoagulants that prolong clotting times.
Special Instructions
The preferred initial test for individuals with supratherapeutic concentrations of heparin, direct thrombin inhibitors, Factor Xa inhibitors, extreme factor V deficiency, or lupus anticoagulants with markedly prolonged baseline clotting times is the Factor V Leiden (F5) R506Q Mutation (0097720).
Limitations
Ratios less than 2.00 in this assay suggest APC resistance. The test uses factor V deficient plasma; therefore, APC resistance due to non-factor V mutations will not be detected. The results may not be reliable in the presence of extreme factor V deficiency or direct oral anticoagulants (DOACs).
FDA ApprovedNew York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 13590-5
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1.5 mL
Minimum Volume
1 mL
Container
ARUP standard transport tube
Collection Instructions
Use lt. blue (sodium citrate) tube. Refer to ARUP's hemostasis/thrombosis specimen handling guidelines.
Storage Instructions
CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.
Causes for Rejection
Serum. EDTA plasma, clotted or hemolyzed specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 hours |
| Refrigerated | Unacceptable |
| Frozen | 3 months |
Other tests from different labs that may be relevant