Sign in →

Test Code FVLAPC Factor V Leiden/Activated Protein C Resistance

Specimen and Container/Tube

Specimen Type: Plasma and Whole Blood

Preferred Specimen: 1 Light Blue Top Tube, 3.2% Sodium Citrate and 1 Lavender Top Tube

Other Acceptable specimens: N/A

Specimen Handling and Transport Instructions

UCMC Onsite Instructions: 

Collect specimen per standard collection procedure and send to laboratory immediately. 

 

NOTE: Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.

 

UCMC Offsite and UC MedLab Outreach Instructions: 

 

Blue top tube specimen instruction:

  • Collect specimen per standard collection procedure.
  • Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.
  • Centrifuge specimens at >2500 x g for 10 minutes at room temperature.
  • Carefully remove plasma from cells using a plastic transfer pipette avoiding buffy coat.
  • Aliquot removed plasma into 2 plastic tubes containing a minimum of 0.5 mL of specimen in each tube.
  • Plasma samples must then be frozen at -20oC.
  • Once solidly frozen, they must be shipped on dry ice. Samples that have thawed in transit will be rejected.

Lavender top tube instructions:

  • Collect specimen per standard collection procedure.
  • Once the lavender top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.
  • Send whole blood refrigerated.
  • Do Not centrifuge
  • Do Not freeze

Rejection Criteria

  • Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits. 
  • Specimens that have wrong ratio of blood to anticoagulant (fill volume), clotted or grossly hemolyzed.

Reference Values

 

Test

Age

Sex

Reference Range

APCR

All

All

≥ 2.29

Critical Values

Analyte

Unit

Low

High

Age

N/A

N/A

N/A

N/A

N/A

CPT Codes

APCR: 85307

FVI: 83908

LOINC Codes

13590-5

Volume

Preferred Volume: 1 mL plasma and 2 mL blood in 4 mL lavender tube

 

Minimum Volume: 0.5 mL plasma and 2 mL blood in 4 mL lavender tube

Specimen Stability

Storage Temperature

Stability

Room temperature

Blue top tube: 4 hours

Refrigerated

Lavender Whole Blood: Refrigerate up to 72 hours

Frozen

Citrated Plasma: 30 days

Collection Instructions

Collect specimen per standard laboratory collection procedures. 

 

NOTE: Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.

 

Turnaround Time

Turnaround times are relative to the time the specimen is received in the test laboratory. 

STAT Turnaround Time: N/A

 

Routine Turnaround Time: Up to 4 days

 

Testing Schedule: Twice a week, Monday to Friday. First shift only.

Clinical Indications

Evaluation of patients with venous thromboembolism (VTE)

Methodology

Activated Protein C (APC) resistance: clotting

Factor V Leiden gene mutation: PCR

Synonyms/Keyword Search

FVL; APCR; Factor V Leiden;
Activated Protein C Resistance

Additional Information

Initial testing will consist of a functional assay for Activated Protein C (APC) resistance. If an abnormality in the APC resistance testing is found, reflexive testing for the Factor V Leiden gene mutation will also be performed.

 

Unlike tests for levels of Protein C, Protein S, orantithrombin, testing for APC resistance is expected to retain validity even in the setting of recent thrombotic events.

 

Absence of an abnormality in the Factor V Leiden gene mutation testing, despite the presence of APC resistance, may be seen in the setting of acquired APC resistance, or in the rare instance of a mutation in Factor V at a locus other than that of the Leiden mutation.

 

All 3.2% sodium citrate light blue top tubes must have 9 to 1 ratio of blood to anticoagulant.

Last Review Date

08/19/2024

Related Tests