Test Overview
Test Methodology

Chromogenic Activity Assay

Test Usage

Used to identify and quantitate a Protein C defect or deficiency in those patients subject to recurrent venous thrombosis or pulmonary emboli.

Reference Range *

80 - 150%

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

The presence of Factor V Leiden may lead to lower protein C values. This methodology detects the amidolytically active portion of the activated protein C, including the non-carboxylated molecules synthesized in vitamin K deficiency. Thus, in conditions of vitamin K deficiency, a higher protein C activity is found with chromogenic Protein C than when using a coagulometric method.

Test Details
Days Set Up
Tuesday
Analytic Time

1 hour

Soft Order Code
PCA
MiChart Code
Protein C Activity
Synonyms
  • PCA
  • PROTEIN C ACTIVITY
Laboratory
Hematopathology
Section
Coagulation
Specimen Requirements
Collection Instructions

Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.

Rejection Criteria
Specimens will be rejected if not properly filled, clotted, grossly hemolyzed, or contaminated with heparin.
Contraindications
This test is not indicated in patients receiving Coumadin (warfarin) therapy. This test is not indicated for inpatient evaluation of acute thrombosis.
Blue Top Tube
Normal Volume
Full 2.7mL tube or 1mL plasma aliquot
Minimum Volume
Full 1.8mL tube or 1mL plasma aliquot
Billing
CPT Code
85303
Fee Code
31113
LOINC
6007-9
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