Sign in →

Test ID: FACTV Coagulation Factor V Activity Assay, Plasma

Reporting Name

Coag Factor V Assay, P

Useful For

Diagnosing congenital deficiencies (rare) of coagulation factor V

 

Evaluating acquired deficiencies associated with liver disease, factor V inhibitors, myeloproliferative disorders, and intravascular coagulation and fibrinolysis

 

Investigation of prolonged prothrombin time or activated partial thromboplastin time

Specimen Type

Plasma Na Cit


Advisory Information


Coagulation testing is highly complex, often requiring the performance of multiple assays and correlation with clinical information. For that reason, consider ordering a Coagulation Consultation.



Necessary Information


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



Specimen Required


Patient Preparation: Patient must not be receiving Coumadin (warfarin) or heparin therapy

Specimen Type: Platelet-poor plasma

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

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Specimen must be collected prior to factor replacement therapy.

2. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing in Special Instructions.

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

4. Aliquot plasma into a plastic vial, leaving 0.25 mL in the bottom of centrifuged vial.

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

Additional Information:

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

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


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Na Cit Frozen 14 days

Reference Values

>1 month: 70%-165%

<1 month: Normal, full-term and premature newborn infants may have  mildly decreased levels (≥30% to 35%) which reach adult levels within 21 days postnatal.

*See Pediatric Hemostasis References section in Coagulation Guidelines for Specimen Handling and Processing in Special Instructions.

Day(s) and Time(s) Performed

Monday through Friday

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

85220

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FACTV Coag Factor V Assay, P 3193-0

 

Result ID Test Result Name Result LOINC Value
FACTV Coag Factor V Assay, P 3193-0

Clinical Information

Factor V is a vitamin K-independent protein synthesized in the liver and in other tissues (endothelium, megakaryocytes/platelets). In its thrombin-activated form (factor Va), it serves as an essential cofactor in the prothrombinase enzyme complex, which converts prothrombin to thrombin (the prothrombinase complex consists of the enzyme, activated factor X, factor Va cofactor, a phospholipid surface, and calcium).

 

Deficiency of factor V may cause prolonged prothrombin time and activated partial thromboplastin time and may result in a bleeding diathesis. Plasma biological half-life varies from 12 to 36 hours.

 

Platelets contain 20% to 25% of the factor V in blood. Factor V (also known as labile factor) is highly susceptible to proteolytic inactivation, with the potential for spuriously decreased assay results.

Interpretation

Acquired deficiencies are much more common than congenital.

 

Patients that are congenitally deficient homozygous generally have activity levels less than or equal to10% to 20%.

 

Patients that are congenitally deficient heterozygous generally have activity levels less than or equal to 50%.

 

Congenital deficiency may occur in combined association with factor VIII deficiency.

Clinical Reference

1. Girolami A, Scandellari R, Scapin M, Vettore S: Congenital bleeding disorders of the vitamin K-dependent clotting factors. Vitam Horm. 2008;78:281-374

2. Brenner B, Kuperman AA, Watzka M, Oldenburg J: Vitamin K-dependent coagulation factors deficiency. Semin Thromb Hemost. 2009 Jun;35(4):439-446

3. Asselta R, Peyvandi F: Factor V deficiency. Semin Thromb Hemost. 2009 Jun;35(4):382-389

4. Lippi G, Favaloro EJ, Montagnana M, et al: Inherited and acquired factor V deficiency. Blood Coagul Fibrinolysis. 2011;22(3):160-166

5. Spreafico M, Peyvandi F: Combined FV and FVIII deficiency. Haemophilia. 2008 Nov;14(6):1201-1208

6. Kottke-Marchant K, ed: Laboratory Hematology Practice. Wiley Blackwell Publishing; 2012

Analytic Time

1 day

Method Name

Optical Clot-Based

Mayo Clinic Laboratories | Hematology Catalog Additional Information:

mml-coagulation-disorders