Rituximab in the treatment of autoimmune haematological disorders

Current treatment regimens for haematological autoimmune diseases are relatively non-selective and are often associated with considerable toxicity. Recently, it has become clear that B cells play a key role in both the development and perpetuation of autoimmunity, suggesting that B-cell depletion could be a valuable treatment approach for patients with autoimmune diseases. This article reviews data supporting the use of rituximab - an anti-CD20 monoclonal antibody that specifically depletes B cells - in four key autoimmune haematological disorders: idiopathic thrombocytopenic purpura (ITP); autoimmune haemolytic anaemia (AIHA); acquired haemophilia; and thrombotic thrombocytopenic purpura (TTP). Although treatment of ITP, AIHA, acquired haemophilia and TTP with rituximab is still relatively uncommon, results from case series and small phase II trials indicate that patients of all ages can respond to rituximab, irrespective of the number or type of prior treatments that they have received. Moreover, patients with these diseases receiving rituximab experienced predominantly mild adverse events, with only a few serious adverse events reported. These data suggest that rituximab provides an effective and well-tolerated alternative treatment option for patients with ITP, AIHA, acquired haemophilia and TTP, many of whom have limited treatment choices.