Activated Protein C Resistance V, with Reflex to Factor V Leiden, Blood and Plasma

Casandra

Casandra Test Code MC51905Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID APCRRCPT Code 85307

Activated Protein C Resistance V, with Reflex to Factor V Leiden, Blood and Plasma

Clinical Use

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.

Test Details

New York Approved