
Introduction
Allo-antibodies to factor VIII occur in 10 to 15% of patients with classical haemophilia (usually < 10% FVIII level) and usually within the first 40 treatment-exposure days. Inhibitors do not occur after 200 treatment-exposure days. Factor IX antibodies are extremely rare.
Information Required
- Titre of the factor VIII inhibitor at the time of therapy.
- Less than 5 Bethesda Units (BU) can be treated with neutralising doses of Factor VIII.
- 5 to 20 BU may respond to neutralising doses of Factor VIII.
- More than 20 BU are unresponsive to FVIII concentrate.
- Is the patient known to have an inhibitor of the low or high responder type?
- Majority of patient (> 75%) are high responders.
- A low responder antibody remains < 5 BU/mL.
- Severity and site of bleeding.
Topic Code: 5268