Activated Protein C Resistance V, with Reflex to Factor V Leiden, Blood and Plasma
Use
This test is useful for evaluating patients with incident or recurrent venous thromboembolism (VTE) and individuals with a family history of VTE. Resistance to activated protein C (APC resistance) is characterized by a reduced anticoagulant response of patient plasma after adding a standard amount of APC. It helps in identifying individuals with hereditary APC resistance and particularly those with Factor V Leiden variant, a common genetic risk factor for VTE. The test provides necessary clinical correlations to guide patient management and treatment options.
Special Instructions
For New York clients, informed consent is required. Document on the request form or electronic order that a copy is on file. The assay should be performed as a part of a consultative coagulation test panel with interpretive reporting. The patient should ideally fast for 8 hours before specimen collection, although it is not required. The collection should adhere to provided guidelines to ensure accurate results.
Limitations
The assay is specific for detecting inherited APC resistance but does not detect acquired resistance. Preanalytical conditions, such as prolongation of clotting times due to lupus-like anticoagulants, specific coagulation factor inhibitors, or anticoagulant effects, can interfere with testing accuracy. The test is most effective when conducted alongside other coagulation assays. Discrepant results may occur in patients with liver or stem cell transplants or due to improper specimen handling or mix-up. The assay's reliability is contingent on proper specimen preparation to prevent platelet contamination.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 13590-5
- 13590-5
- 48591-2
Result Turnaround Time
4-7 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
3 mL
Container
Lavender top (EDTA)
Collection Instructions
Invert several times to mix blood. Send whole blood specimen in original tube. Do not aliquot.
Patient Preparation
Fasting: 8 hours, preferred but not required
Causes for Rejection
Gross hemolysis, lipemia, icterus will lead to specimen rejection.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |