Test Code LAB5032 Activated Protein C Resistance (APCR), Blood

Performing Laboratory

Barnes-Jewish Hospital Laboratory

Methodology

Modified, aPTT-Based Activated Protein C Assay

Testing Algorithm:

If result is abnormal, LAB6127 Factor V Leiden (FVL) Mutation Detection will be performed at an additional charge.

Literature References:

Package insert: Factor V Leiden (APC Resistance V), v. 301557A R6. Instrumentation Laboratory Company, Lexington, MA, 06/2005.

Specimen Requirements

Specimen Type: Sodium Citrate plasma and whole blood EDTA

Container/Tube: Light-blue top (citrate) and lavender EDTA

Specimen Volume: Full tube light-blue (citrate) and full lavender EDTA

Specimen Minimum Volume: Full citrate tube and 2 mL lavender

Collection Instructions:

Draw a discard blue top tube prior to drawing a light-blue top (citrated) tube if using a Winged Infusion Set. Discard tube should be under filled and discarded.
Clotted blood or an insufficient specimen is not acceptable.
Avoid phlebotomy techniques which cause hemolysis and heparin contamination.
Follow nursing policy on volume of blood to discard prior to collecting blood from indwelling heparinized catheters.

Analyte Stability:
4 hours at 18° C to 24° C.

Whole blood may be transported to BJH Core Laboratory on wet ice within 8 hours of collection. Refrigerate blood until transport.

Platelet-free plasma can be frozen at -20 for transport on dry ice up to 72 hours
or stored 6 months at -70° C.

Additional Information: If the patient is a hospital patient and the hematocrit is >55%, call Barnes-Jewish Hematology Laboratory at 314-362-5203 for instructions.

Day(s) Test Set Up

Friday

Cut-off time: 0700

Turnaround Time:
STAT: not available
Routine: results available the day of testing

Test Classification and CPT Coding

85307
81241 (if appropriate)

Reference Values

Ratio: >2.3

Literature References:

1. Bertina RM, Koeleman BPC, Koster T, et al. Mutation in blood coagulation factor V associated with resistance to activated protein. C Nature 1994;369:64-7.

2. Van Cott EM, Soderberg BL, Laposata M. Activated protein C resistance, the factor V Leiden mutation, and a laboratory testing algorithm. Arch Pathol Lab Med 2002;126:577-582.

Specimen Transport Temperature

Ambient Yes/Refrigerate Yes/Frozen Yes

Additional Information

For BJH Laboratory Use Only
Analyte Stability:

4 hours at 18° C to 24° C.