8 hours
Test Updated:
Bethesda Inhibitor
Factor 8 Inhibitor
Factor VIII Inhibitor Assay
Factor VIII:C Inhibitor Assay
Inhibitor Assay VIII
INHIB8
INH8
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Test Overview
Nijmegen Bethesda Assay
Evaluation of increased bleeding problems in patients with hemophilia or abrupt-onset bleeding distress in postpartum women, patient with collagen vascular disorders, or elderly individuals. Assay is suitable for both treated and untreated patients.
The Factor VIII inhibitor level in a normal individual is less than 0.5 Bethesda unit. 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.
Specimen Requirements
The Factor VIII level is included in the order for the Factor VIII Inhibitor Assay. The inhibitor level will not be performed if the Factor VIII activity level is greater than 50%. Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. 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.
MLabs recommends performing or ordering a Factor VIII Assay activity level prior to ordering the Factor VIII Inhibitor Assay because the Inhibitor Assay will not be performed if the Factor VIII level is greater than 50%. A Factor VIII level is included in the order for the Factor VIII Inhibitor Assay. Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a plastic vial, 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.
