Severe Evans's syndrome secondary to interleukin-2 therapy: treatment withchimeric monoclonal anti-CD20 antibody

Interleukin-2 (IL-2) acts by increasing the efficiency of the immune system to exert a tumoricidal effect. Although it is well known that immune stimu lation with IL-2 plays a role in unmasking autoimmune phenomena such as aut oimmune thyroiditis, hematological effects such as anemia and thrombocytope nia are more frequently due to toxic non-immune mechanisms. We describe a p atient who developed severe Evans's syndrome [autoimmune hemolytic anemia ( AHA) and immune thrombocytopenic purpura (ITP)] secondary to IL-2 therapy. ITP was refractory to multiple treatment modalities including steroids and splenectomy. ITP and AHA were initially managed with intravenous gamma glob ulin therapy and frequent blood transfusions, respectively. Ultimately, imm unosuppressive therapy with cyclophosphamide and chimeric monoclonal anti-C D20 antibody (rituximab) were successful in inducing complete remission of Evans's syndrome.