Protein C, Functional
0030113
Ordering Recommendation
Recommended test to detect protein C deficiency. Do not order if individual has been on warfarin in the previous 2-4 weeks.
Submit With Order
Mnemonic
PROT C F
Methodology
Clotting
Performed
Sun-Sat
Reported
1-2 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.  
Specimen Preparation
Transfer 1.5 mL platelet-poor plasma to an ARUP Standard Transport Tube. (Min: 1 mL)  
Storage/Transport Temperature
CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.  
Unacceptable Conditions
Serum. Non-frozen or hemolyzed specimens.  
Remarks
 
Stability
Ambient: 4 hours; Refrigerated: Unacceptable; Frozen at -20°C: 3 months, at -70°C: 6 months  
Reference Interval
1-4 days: 17-53%
5-29 days: 20-64%
30-89 days: 21-65%
90-179 days: 28-80%
180-364 days: 37-81%
1-6 years: 40-92%
7-9 years: 56-144%
10-11 years: 59-143%
12-13 years: 57-142%
14-15 years: 56-162%
16-17 years: 68-154%
18 years and older: 77-173%
Interpretive Data
Patients on warfarin may have decreased protein C values. Patients should be off warfarin therapy for two weeks for accurate measurement of protein C levels. Artificially increased functional protein C values may be due to heparin therapy or the presence of direct thrombin inhibitors or factor Xa inhibitors.
Note
CPT Code(s)
85303
Components
Component Test Code*Component Chart Name
0030113Protein C Functional
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Cross References
  • Functional Protein C
  • Protein C Activity
  • Protein C, Functional, Plasma