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.
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.
Submit With Order
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
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Aliases
  • Functional Protein C
  • Protein C Activity
  • Protein C, Functional, Plasma