Activated Protein C Resistance (APCR)
Also known as: APCR
Use
Screening test for the factor V Leiden gene mutation and other causes of activated protein C resistance
Special Instructions
If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted. Refer to Coagulation Collection Procedures for directions. The sample should be mixed immediately by gentle inversion at least six times.
Limitations
This assay detects thrombotic risk factors other than factor V Leiden. It should not be used for patients receiving thrombin inhibitors such as hirudin and argatroban. Elevated factor VIII levels can normalize the aPTT and reduce the anticoagulant effect of aPC. Abnormal results can occur in pregnancy due to decreased protein S and increased factors V and VIII levels. In some cases, it may fail to distinguish heterozygous from homozygous factor V Leiden mutations.
Methodology
Other
Biomarkers
LOINC Codes
- 13590-5
- 13590-5
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
Not provided
Container
Blue-top (sodium citrate) tube
Collection Instructions
Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. The sample should be mixed immediately by gentle inversion at least six times.
Patient Preparation
Do not draw from an arm with a heparin lock or heparinized catheter. Avoid warfarin (Coumadin®) therapy for two weeks prior to the test and heparin (direct Xa and thrombin inhibitor therapies) for about three days prior to testing.
Storage Instructions
Freeze
Causes for Rejection
Gross hemolysis; clotted specimen; frozen specimen thawed in transit; tubes <90% full; improper labeling; specimen collected in tube other than 3.2% citrate
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 28 days |