Factor VIII Inhibitor (Porcine)
Description:
Inhibitors to coagulation Factor VIII (FVIII) are antibodies that may occur in 10-15% of patients with congenital Haemophilia A. An autoimmune response to endogenous FVIII may rarely occur leading to acquired Haemophilia A. The use of non-human FVIII replacement therapy may be clinically indicated in this instance. The Nijmegen Bethesda assay has been modified to measure porcine FVIII recovery values following incubation of test plasma with porcine reference standand. One unit of inhibitor is defined as the amount that will neutralise 50% of the reference plasma containing 100% porcine FVIII after a 2 hour incubation.
This test is not currently included in the laboratory's UKAS scope of accreditation to ISO15189:2012.
This test is not currently included in the laboratory's UKAS scope of accreditation to ISO15189:2012.
Clinical details:
Recombinant porcine Factor VIII may be used to treat patients with inhibitors, particularly in acquired Haemophilia A. The use of a porcine FVIII reference standard in the Bethesda assay allows the detection of inhibitory activity specific to the porcine FVIII protein.
Reference range:
Not detected
Synonyms or keywords:
Obizur
Units:
NBU/mL
Department:
Location:
Sample type and Volume required:
External requests: Citrated platelet poor plasma (1mL x 1 aliquot) or 3.5mL whole blood citrate Internal requests: please refer to EPR label
Turnaround time:
7-12 days
Special sample instructions:
The sample should be analysed or processed & stored within 4 hours of venepuncture. Please ensure sample tubes are filled exactly to the fill-line as underfilling or overfilling creates a dilution error and leads to inaccurate results.
Storage and transport:
It is advised that citrated plasma is frozen prior to transport and sent to the laboratory on dry ice to maintain sample quality and integrity. Whole blood can be sent at room temperature, but must be received within 4 hours of venepuncture. Suggest laboratory is contacted in advance of sample dispatch.
Contacts:
Diagnostic Haemostasis and Thrombosis Department
St Thomas': 020 7188 2797; Guy's: 020 7188 7188 ext. 53860
St Thomas' Hospital
North Wing - 4th and 5th Floors
Westminster Bridge Road
London SE1 7EH
Laboratory opening times
24/7
Guy's Hospital
Southwark Wing - 4th Floor
Great Maze Pond
London SE1 9RT
Outside core hours, contact Duty Haemostasis Biomedical Scientist
North Wing - 4th and 5th Floors
Westminster Bridge Road
London SE1 7EH
Laboratory opening times
24/7
Guy's Hospital
Southwark Wing - 4th Floor
Great Maze Pond
London SE1 9RT
Outside core hours, contact Duty Haemostasis Biomedical Scientist
Last updated: 05/11/2021
