Routine comprehensive evaluation of patients with severe hemophilia. Evaluation of increased bleeding problems in patients with hemophilia.
The Factor IX inhibitor level in a normal individual is <0.5 Bethesda units. Critical value: greater than 0.5 Bethesda unit (if no prior inhibitor present).
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.
Test will not be performed if Factor IX level is above 50%.
- Bethesda Inhibitor
- Factor 9 Inhibitor
- Factor IX Inhibitor Assay
- Factor IX:C Inhibitor Assay
- Inhibitor Assay IX
Please contact special coagulation lab.
The Factor 9 assay activity level is included in this test order. The inhibitor level will not be performed if the factor activity level is greater than 50%.Collect specimen in two blue top (citrate 3.2%) tubes. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma from each blue top tube into separate polypropylene plastic vials, 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.
Factor IX inhibitors occur most commonly in patients with severe x-linked recessive deficiencies of factor IX activity and may compromise the care of these patients severely.