Epic Test Code LAB308 Coagulation Factor IX Activity Assay, Plasma
Additional Codes
MML Code: F_9
NY State Approved
YesPerforming Laboratory
Mayo Clinic Laboratories in RochesterReporting Name
Coag Factor IX Assay, PMethod Name
Optical Clot-Based
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma Na Cit | Frozen | 14 days |
Ordering Guidance
Coagulation testing is highly complex, often requiring the performance of multiple assays and correlation with clinical information. For that reason, consider ordering a Coagulation Consultation.
Necessary Information
If priority specimen, mark request form, give reason, and request a call-back.
Specimen Required
Specimen Type: Platelet-poor plasma
Patient Preparation: Patient must not be receiving Coumadin (warfarin) or heparin therapy.
Collection Container/Tube: Light-blue top (3.2% sodium citrate)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Specimen must be collected prior to factor replacement therapy.
2. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.
3. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.
4. Aliquot plasma into a plastic vial, leaving 0.25 mL in the bottom of centrifuged vial.
5. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or ideally, at or below -40° C.
Additional Information:
1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
2. Each coagulation assay requested should have its own vial.
Blood Tube Draw Volume
Min 90% draw volume
Specimen Type
Plasma Na CitSpecimen Minimum Volume
0.5 mL
Reference Values
≤6 months: Normal, full-term newborn infants or healthy premature infants may have decreased levels (≥20%), which may not reach adult levels for 180 or more days postnatal.* (Literature derived)
>6 months: 65-140%
*See Pediatric Hemostasis References section in Coagulation Guidelines for Specimen Handling and Processing.
Report Available
1 to 3 daysDay(s) Performed
Monday through Saturday
CPT Code Information
85250
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Useful For
Diagnosing deficiencies, particularly hemophilia B (Christmas disease)
Assessing the impact of liver disease on hemostasis
Investigation of a prolonged activated partial thromboplastin time
Special Instructions
Disease States
- Hemophilia B
Clinical Information
Factor IX is a vitamin K-dependent serine protease synthesized in the liver and participates in the intrinsic coagulation pathway. Its biological half-life is 18 to 24 hours.
Congenital deficiency is inherited as an X-linked recessive bleeding disorder (hemophilia B). Severe deficiency (<1%) is characterized by hemarthroses, deep tissue bleeding, excessive bleeding with trauma, and ecchymoses.
Acquired deficiency is associated with liver disease, vitamin K deficiency, warfarin therapy, and inhibitors (rare).
Interpretation
Acquired deficiency is more common than congenital.
Mild hemophilia B: 5% to 50% activity
Moderate hemophilia B: 1% to 5% activity
Severe hemophilia B: <1% activity
Cautions
Liver disease, warfarin therapy, or vitamin K deficiency may decrease factor IX levels.
Specimen Retention Time
7 daysTesting Algorithm
For information see Hemophilia Testing Algorithm
Forms
If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.