Factor V Activity

Orderable EAP code:

LAB00257

Billable EAP Codes:

80001095 x 1

CPT Codes:

85220 x 1

Lab Section:

Hemostasis and Thrombosis

Turnaround Time:

1 to 3 days

Test Schedule:

Monday through Friday 8:30 am to 4:30 pm.

Units:

%

Critical Values:

Less than 5%

Specimen Requirements:

Two full 2.7 mL LIGHT BLUE top tubes, 3.2% sodium citrate. Hemostasis & Thrombosis Lab sodium citrate specimens must be processed and frozen within 2 hours of specimen collection. Stability is 14 days at -70 C.

Draw volume is critical due to the liquid anticoagulant. Allow tubes to fill by vacuum.
• Tubes with rubber stopper: fill to line on label.
• Tubes with plastic (Hemogard) cap: the fill level is above the top of the label.
• Syringe: do not remove the vacutainer stopper. Insert the needle through the stopper and allow the tube to fill by vacuum. Do not overfill the vacutainer.
• Pediatric tubes have no vacuum. Remove the cap and add blood to the 1.3 mL mark. Do not overfill.

OHSU clinics must cab the specimen to the Core Lab, Hatfield Research Center, 9th Floor (room 9D20) if processing is delayed or not possible on site. A phone call is helpful to alert the lab at 503-494-7383.

Detailed specimen collection and processing instructions are located under Lab Sections and then the Hemostasis and Thrombosis (Opens in a new window) section.

For referral testing, submit one tube with 1.0 mL frozen platelet poor citrated plasma.

Pediatric Specimen Requirements:

One full pediatric 1.3 mL LIGHT BLUE top tube, 3.2% sodium citrate. Hemostasis & Thrombosis Lab sodium citrate specimens must be processed and frozen within 2 hours of specimen collection. Stability is 14 days at -70 C.

For pediatric patients requiring multiple coagulation tests, please call 503-494-7383 regarding draw volumes.

Reference Range:

62% to 139%
For children less than 6 months, see link to published reference ranges (Opens in a new window)

Comments:

Avoid warfarin (Coumadin) therapy for 2 weeks and heparin therapy for 2 days prior to the test.

Assay to document factor V deficiency. Factor V deficiency is inherited as an autosomal recessive, males and females are equally affected. Only homozygotes have bleeding symptoms; heterozygotes are largely asymptomatic. Symptoms include ecchymoses, epistaxis, menorrhagia, and bleeding following trauma and tooth extraction. GI hemorrhage and hemarthrosis may occur. Severity of bleeding does not correlate directly with factor V level and symptoms are often mild, even in homozygotes. Homozygous V deficient individuals usually have prolonged whole blood clotting time, prothrombin time, and APTT.

Methodology: PT based clotting method.

Synonyms:

F5A
Factor 5
FVA