Treatment of autoimmune hemolytic anemias

Abstract

Autoimmune hemolytic anemia (AIHA) is a relatively uncommon disorder caused by autoantibodies directed against self red blood cells. It can be idiopathic or secondary, and classified as warm, cold (cold hemagglutinin disease (CAD) and paroxysmal cold hemoglobinuria) or mixed, according to the thermal range of the autoantibody. AIHA may develop gradually, or have a fulminant onset with life-threatening anemia. The treatment of AIHA is still not evidence-based. The first-line therapy for warm AIHA are corticosteroids, which are effective in 70-85% of patients and should be slowly tapered over a time period of 6-12 months. For refractory/relapsed cases, the current sequence of second-line therapy is splenectomy (effective approx. in 2 out of 3 cases but with a presumed cure rate of up to 20%), rituximab (effective in approx. 80-90% of cases), and thereafter any of the immunosuppressive drugs (azathioprine, cyclophosphamide, cyclosporin, mycophenolate mofetil). Additional therapies are intravenous immunoglobulins, danazol, plasma-exchange, and alemtuzumab and high-dose cyclophosphamide as last resort option. As the experience with rituximab evolves, it is likely that this drug will be located at an earlier point in therapy of warm AIHA, before more toxic immunosuppressants, and in place of splenectomy in some cases. In CAD, rituximab is now recommended as first-line treatment.

Figure 1.

Treatment algorithm for warm AIHA in adults. SR: sustained response defined as maintenance of Hb values >10 g/dL over time; NR: no response; d: day; w: week; AZA: azathioprine; CyA: cyclosporine A; CTX: cyclophosphamide; MMF: mycophenolate mofetil; PEX: plasma exchange; IVIG: intravenous immunoglobulin.