Health Lab

Test Name:

PROTEIN C ACTIVITY REFLEX TO PROTEIN C ANTIGEN

Test Code:

2188103

Alias:

LAB489
Protein C, Functional

CPT Code(s):

85303

Preferred Specimen:

2.0 mL plasma

Container:

1 - full Sodium Citrate (blue) tube

Alternate Container:

None

Minimum Volume:

1 - full Sodium Citrate (blue) tube

Collection Instructions:

Mix tubes gently by inverting 5-10 times immediately after filling. Centrifuge for 15 minutes within 1 hour of collection. Using a plastic pipette, remove plasma taking care to avoid the WBC/platelet buffy layer and transfer plasma into a properly labeled transfer tube. Centrifuge the transferred plasma a second time and transfer platelet poor plasma into a new properly labeled transfer tube. Label tube as "platelet poor". Freeze immediately.

*Send both the transfer tube and the original tubes to the lab.

Transport Temperature:

Plasma: Frozen
Original tubes: Room Temperature

Stability:

Frozen: 14 days

Rejection Criteria:

Refrigerated specimens

Room Temperature specimens

Partially thawed specimens

Additional Information:

Reflex to Protein C Antigen if Protein C Activity is <70

Schedule:

Turnaround Time: 1-5 days

Method:

Quantification of activated Protein C with a synthetic chromogenic substrate

Performing Lab:

Northwestern Memorial Hospital

Clinical Significance:

Protein C is a vitamin K dependent protein that is present in plasma as a zymogen. Deficiency of protein C is associated with recurrent venous thrombosis, especially in young adults. Acquired deficiencies of Protein C are associated with hepatic disorders, oral anticoagulant therapy, and disseminated intravascular coagulation.

Use:

Updated: 01/12/2024

Reference Ranges:

Refer to patient report

Reference Range Table

Result	Units	Gender	Age	Range
Protein C	% activity	Both	0 Year - 999 Year	74 - 134%

The CPT codes included in this publication are in accordance with Current Procedural Terminology, a publication of the American Medical Association. CPT codes are provided here for the convenience of our clients; however, correct coding often varies from one carrier to another, and HealthLab may bill specific carriers using codes other than those shown. Clients who bill for services should verify the code(s) with the applicable payor to confirm that their use is appropriate in each case.