The management of inhibitors in haemophilia A: introduction and systematic review of current practice

Summary.  Haemophilia is the commonest bleeding disorder in the UK, affecting approximately 5400 people, almost all of them male. In haemophiliacs, reduced levels, or absence, of factor VIII (FVIII) cause bleeding episodes, typically into joint spaces or muscles. Haemophilia is generally treated with exogenous FVIII. However, in some haemophiliacs, therapeutically administered FVIII comes to be recognized as a foreign protein, stimulating the production of antibodies (inhibitors), which react with FVIII to render it ineffective. Alternative treatment strategies then have to be used to manage bleeding episodes. In addition, strategies have been developed to attempt to abolish inhibitor production through the induction of immune tolerance. A systematic review was undertaken of current international practice for the clinical management of haemophilia A patients with inhibitors to FVIII, concentrating on literature published from 1995 onwards. Although it can be difficult to determine what constitutes current practice, current guidelines indicate that immune tolerance induction is seen as desirable, with the choice of regimen dependent on patient characteristics, familiarity with regimens and cost. Various approaches, based on similar factors, are used to control bleeding episodes.