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Test Code LAB846 Activated Protein C Resistance V (APCRV), Plasma

Reporting Name

Activated Protein Resistance V, P

Useful For

Evaluation of patients with incident or recurrent venous thromboembolism (VTE)

 

Evaluation of individuals with a family history of VTE

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Plasma Na Cit


Ordering Guidance


Although this assay can be performed in the absence of other coagulation tests and clinical information, it is most reliably performed as part of a consultative coagulation test panel with interpretive reporting (including appropriate testing of the same specimen to evaluate for the presence or absence of coagulation abnormalities or conditions that may affect interpretation of the APC resistance assay). This test is included among a panel of tests designated AATHR / Thrombophilia Profile, Plasma and Whole Blood.



Necessary Information


If a priority specimen, mark request form, give reason, and request a call-back.



Specimen Required


Specimen Type: Platelet-poor plasma

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Polypropylene vial

Specimen Volume: 1 mL

Collection Instructions:

1. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.

2. Centrifuge, transfer all plasma into a vial, and centrifuge plasma again.

3. Aliquot plasma into a vial leaving 0.25 mL in the bottom of centrifuged vial.

4. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally at-40° C or below.

Additional Information:

1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

2. If priority specimen, mark request form, give reason, and request a call-back.

3. Each coagulation assay requested should have its own vial.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Plasma Na Cit Frozen 14 days

Reference Values

APCRV RATIO

≥2.3

Pediatric reference range has neither been established nor is available in scientific literature. The adult reference range likely would be applicable to children older than 6 months.

Day(s) Performed

Monday through Friday

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

85307

LOINC Code Information

Test ID Test Order Name Order LOINC Value
APCRV Activated Protein Resistance V, P 13590-5

 

Result ID Test Result Name Result LOINC Value
APCR APCRV Ratio 13590-5
INT55 Interpretation 48591-2

Cautions

This assay is highly sensitive and specific for inherited activated protein C (APC) resistance, most commonly due to the factor V Leiden mutation, but it will not detect patients with acquired APC resistance. Persons with acquired APC resistance are at similar risk for venous thromboembolism.

 

Preanalytical conditions of the patient and the blood specimen are extremely important for reliable performance and interpretation of testing for APC resistance. Plasmas demonstrating prolongation of clotting times (prothrombin time, activated partial thromboplastin time) for reasons other than anticoagulant effects (eg, lupuslike anticoagulants or specific coagulation factor inhibitors) generally cannot be reliably tested for the presence or absence of APC resistance. Proper preparation of the blood (plasma) specimen is extremely important to help ensure accuracy of results and interpretation.

 

The activated protein C resistance ratio (APCRV) assay has greater than 99% sensitivity for detecting the presence of a factor V Leiden mutation. Discrepant results of plasma-based APCRV and DNA-based factor V Leiden testing may occur in recipients of liver or allogeneic hematopoietic stem cell transplants; or due to anticoagulant effects such as excess heparin; direct thrombin inhibitors argatroban (Acova), bivalirudin (Angiomax), or dabigatran (Pradaxa); or direct factor Xa inhibitors rivaroxaban (Xarelto), apixaban (Eliquis), and edoxaban (Savaysa); or a sample mix-up. Clinical correlation is suggested. If clinically indicated, consider follow-up repeat APCR testing or direct DNA-based testing for the factor V Leiden (R506Q) mutation (F5DNA / Factor V Leiden [R506Q] Mutation, Blood).

Report Available

1 to 3 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

NY State Approved

Yes

Method Name

Optical Clot-Based

Forms

If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.