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HelpTest Code FA8IN Factor VIII Inhibitor
Clinical Information
Bethesda factor inhibitor method using the one stage clotting assay to detect the presence and titer of a specific factor inhibitor directed agains factor VIII.
Synonym
- FA8IN
- Factor 8 Inhibitor
- Factor VIII Bethesda Titer
- Bethesda Titer
Specimen Required
Preferred Container/Tube: 3.2% Citrate Blue Top - 2.7 mL
Specimen Volume: 2.7 mL
Acceptable Container/Tube: 3.2% Citrate Blue Top - 1.8 mL
Specimen Volume: 1.8 mL
Platelet poor plasma (PPP):
Specimen Volume: 2 - 1 mL aliquots platelet poor plasma (PPP)
Specimen Minimum Volume: 1 - 1 mL aliquot platelet poor plasma (PPP)
Specimen Collection Information
For Outreach, other than OSU Patient Service Centers: Samples must be processed and received frozen/must remain frozen in transit.
For sending frozen plasma specimens, process immediately upon receipt. Centrifuge capped specimen tube in accordance with CLSI H21, at a speed and time required to consistently produce platelet-poor plasma (PPP = platelet count <10 K/uL). Transfer PPP into plastic aliquot tubes, cap and freeze. DO NOT transport until specimens are completely frozen.
Specimen Stability Information
Ambient:
Whole blood: 4 hours
Platelet poor plasma: 4 hours
Frozen:
Platelet poor plasma: PPP removed from the cells and frozen at -20°C or ideally -70°C.
Rejected Due To
- Ambient specimens >4 hours old
- Clotted specimens
- Underfilled or overfilled tube
- Hemolysis
Reference Values
0.0 Bethesda units
Interpretation
Negative
Cautions
Test is not indicated if Factor VIII level is greater than 40%, if patient is receiving anticoagulation therapy, or if the patient is receiving porcine factor replacement therapy.
Method Description
Bethesda method using a 1 stage clotting assay
Performing Lab
Clinical Lab UH
Day(s) Performed
Monday through Friday (excludes OSU holidays)
Report Available
Same day/1 day
Reporting Name
Factor VIII Inhibitor Assay
CPT Code Information
85335
LOINC Code Information
58493-8
3187-2