Name: Protein C Activity
Test Name: Protein C Activity
Health Link Test Code: XPCF
LIS Test Code: PC-ACT
CPT Code(s): 85303
Methodology: Chromogenic Assay
Test is used for the qualitative determination of plasma Protein C activity by chromogenic method.
Days Performed: Mon-Fri, dayshift - day varies. Specimens are accepted at any time. Testing required during off hours must be approved by a Coagulation physician. Call 263-5005 before collection.
In-Lab Turnaround Time: 1 - 2 weeks.
Stat In-Lab Turnaround Time: 1 day.
The assay is more accurate in the measurement of Protein C in patients taking warfarin, dabigatran, rivaroxaban, edoxaban or apixaban.
Collection Container: Light blue top (3.2% NaCitrate)
Do NOT draw through a line containing heparin. The venipuncture MUST be atraumatic to avoid hemolysis and contamination with tissue factors and platelets. Tube must be allowed to fill completely.
Collection Volume: Full 3.5 mL tube
Pediatric Collection Volume: Pediatric tube filled to fill mark
4 hours on spun tube
1 month at -20°C; 6 months at -70°C
Sample Analyzed: Plasma
Testing Volume: 1.5 mL
Pediatric Testing Volume: 0.5 mL
Centrifuge specimen to yield platelet poor plasma (platelet count should be less than 10 K/uL). Separate plasma and transfer to plastic tube or vial. Freeze plasma within 4 hours of collection at -20°C or below.
Outreach Specimen Processing:
Centrifuge specimen to yield platelet poor plasma (platelet count should be 10 K/µL or less). Separate plasma and transfer to labeled plastic tube and spin again. Transfer plasma from second spin to clean plastic labeled tube or vial. Indicate on tube "spun twice". Freeze plasma within 4 hours of collection at -20°C or below.
Transport whole blood specimen at room temperature to UWHC Hospital Laboratory within 4 hours of collection. See Specimen Processing for instructions if transport criteria are not met. Transport frozen plasma aliquot on dry ice to UWHC Hospital Laboratory.
Hemolyzed specimens, clotted specimens, partially filled tubes and whole blood specimens greater than 4 hours old when received by the laboratory are not acceptable.
17 years and up: 70- 150 %NPP
At birth, Protein C levels are only about 35% of adult normal values on average. Mean Protein C levels rise to above 50% of adult normal values by age 6 months, but may remain below adult normal range until the age of 10-16 years.
Interpretation Type: Reference Interval