Children's Hospitals and Clinics of Minnesota
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Lab Dept:

Coagulation

Test Name:

FACTOR II ASSAY

General Information

Lab Order Codes:

F2

Synonyms:

Prothrombin assay; Factor II Activity

CPT Codes:

85210 - Clotting; factor 2, prothrombin, specific

Test Includes:

F2 level reported as a %.

Logistics

Test Indications:

Useful for the detection of a single factor congenital homozygous or heterozygous deficiency or acquired due to Vitamin K deficiency, liver disease or cystic fibrosis.

Lab Testing Sections:

Coagulation

Phone Numbers:

Minneapolis:

Saint Paul:

 

612-813-6280

651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

4 hours

Special Instructions:

Patient should not be receiving Coumadin® or heparin. If so, this should be noted on the request form. Heparin or Warfarin therapy can affect certain coagulation factors or assays, preclude their performance, or cause spurious results. Indicate when specimen is drawn from a line or a heparin lock. Deliver immediately to the laboratory; Do Not use the pneumatic tube system to transport specimen to the laboratory.

Specimen

Specimen Type:

Whole blood

Container:

Light Blue top tube (Buffered Na Citrate 3.2%) tube (2.7 mL size)

Draw Volume:

2.7 mL whole blood

Processed Volume:

0.9 mL plasma

Collection:

Patients with hematocrit levels of >55% must have a special tube made to adjust for the hematocrit. Contact the laboratory for special tube.

Special Processing:

Lab Staff: Centrifuge specimen, remove plasma aliquot. Run specimen or freeze to store.

Patient Preparation:

Avoid Coumadin® therapy for two weeks and heparin therapy for two days prior to the test.

Sample Rejection:

The following specimens will be rejected: Improper tube, Clotted sample, Underfilled tube, Overfilled tube, Mislabeled or unlabeled specimens

Interpretive

Reference Range:

0 - 1 days:

37 - 50%

2 - 5 days:

48 - 78%

6 - 30 days:

51 - 85%

31 - 90 days:

60 - 90%

91 - 180 days:

74 - 102%

6 months - 5 years:

71 – 116%

6 - 10 years:

67 - 107%

11 - 16 years:

61 - 104%

>16 years

70 - 246%

Critical Values:

N/A

Limitations:

Interpretation of the results may be limited if patient is receiving anticoagulant therapy or if test is done more then 4 hours after collection.

Methodology:

Thromboplastin clotting time correction of Factor 2 deficient plasma. Patient dilutions are compared to a known set of standard dilutions and a percentage is determined.

Contraindications:

Patient on anticoagulant therapy.

References:

Andrew M et al (1987) Development of the Human Coagulation System in the Full Term Infant, Blood 70:165-72

Andrew M et al (1988) Development of the Human Coagulation System in the Premature Term Infant, Blood 72:1651-57

Andrew M et al (1992) Development of the Human Coagulation System During Childhood, Blood 80:1198-2005