Orderable EAP code:

LAB00699

Billable EAP Codes:

80001127 x 1

CPT Codes:

85303 x 1

Lab Section:

Hemostasis and Thrombosis

Includes:

INR is reflexed on patients with a low Protein C level.

Turnaround Time:

1 - 3 days 

Test Schedule:

Monday, Wednesday, and Friday.

Units:

%

Interpretation:

Non-coumadin anticoagulants may falsely elevate Protein C values, even when the concurrent PTT is normal.

Specimen Requirements:

Two full 2.7 mL LIGHT BLUE top tubes, 3.2% sodium citrate. 

Specimens must be processed and frozen within 2 hours of specimen collection.

Send 2- 1mL aliquots of platelet poor plasma, samples must remain frozen during storage and shipment. 

Stability is 14 days at -20 C or at -70 C for up to 12 months. 

Detailed instructions are included in this manual under Specialized Lab Services, Hemostasis & Thrombosis (Opens in a new window) section.

Pediatric Specimen Requirements:

One full pediatric 1.3 mL LIGHT BLUE top tubes, 3.2% sodium citrate. 

Specimens must be processed and frozen within 2 hours of specimen collection.

Send 1- 600 uL aliquot of platelet poor plasma, samples must remain frozen during storage and shipment. 

Stability is 14 days at -20 C or at -70 C for up to 12 months. 

For pediatric patients requiring multiple coagulation tests, please call 503-494-7383 regarding draw volumes.

Reference Range:

70% to 140%

For children less than 6 months, see link to published reference ranges (Opens in a new window).

Comments:

This test aids in the diagnosis of patients at risk of venous thromboembolic disease.

Normal, full-term newborn infants or healthy premature infants may have decreased levels of protein C activity (15% to 50%), which may not reach adult levels until later in childhood or early adolescence.

Discontinue Coumadin therapy 1 month prior to testing. Heparin greater than 1.0 U/mL, coumadin, and fibrinolytic agents interfere with this assay. Coumadin decreases Protein C.

Methodology: Clot-based on prolongation of APTT assay.

High doses of standard heparin (greater than 1.0 U/mL) may interfere with a PT mixing study. Anti-Xa agents such as Rivaroxaban may also interfere with PT mixing studies. Clinical correlation is advised.

Synonyms:

Protein C

PTC