APC Resistance
Test Mnemonic
APC
CPT Codes
- 85307 - QTY (1)
LOINC ®
48591-2
Aliases
- Activated Protein C Resistance
Performing Laboratory
Cleveland Clinic Laboratories
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL | Plasma | Sodium citrate (Lt. Blue) | Centrifuge, aliquot and freeze ASAP. | Collection tube must be filled to total fill volume. Inadequately filled tubes will be rejected. Invert to mix 3-4 times. Non-Testing Sites: Centrifuge sample; Aliquot plasma into a separate tube and label with Epic Beaker labels. Specimens should be frozen (-20C or colder). |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | Main Campus: ACCEPTABLE for Whole Blood. (Must be delivered ambient to testing lab less than 4 hours post collection). Non-Testing Sites: UNACCEPTABLE. |
| Refrigerated | Unacceptable |
| Frozen | For Non-Testing Sites: Frozen Plasma is ACCEPTABLE. Centrifuge sample, then aliquot plasma into a separate tube and label with Epic Beaker label. Specimen should be frozen (-20 C or colder) and is stable for 2 months. |
Days Performed
Mon - Fri
Turnaround Time
1 - 3 days
Methodology
| Name | Description |
|---|---|
| Clotting Assay |
Reference Range
| APC Resistance | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Years | 999 Years | Normal | >=2.90 | Ratio |
Special Info
3.2% sodium citrate is the preferred anticoagulant recommended by CLSI. Patient should not be on heparin therapy or DTI therapy.
Clinical Info
Evaluation of hypercoagulable states and thrombotic disease. Factor V Leiden PCR assay can be used to confirm APC resistance due to factor V Leiden. Ratios less than 2.07 suggest APC - resistance. High heparin concentrations (> 1 U/mL) and direct thrombin inhibitor drugs may interfere with test results. Lupus anticoagulant and other coagulation inhibitors may also interfere with test results. Causes of APC resistance other than abnormalities of factor V may not be detected by this assay as all factors except factor V are replaced in the assay.