Refractory Autoimmune Hemolytic Anemia Following Unrelated Cord Blood Transplantation for Acute Lymphoblastic Leukaemia: A Case Report and Review of the Literature.

Autoimmune haemolytic anaemia (AIHA) after hematopoietic stem cell transplantation(HSCT) is a rare severe complication particularly in the paediatric population who underwent umbilical cord blood transplantation(UCBT).The pathogenesis of the post-HSCT AIHA is poorly understood, which frequently difficult to treat and overall prognosis is often poor. We present a case of a 13-year-old boy who developed AIHA 6 months after UCBT with a minor ABO blood group incompatiblity, 5/6 HLA matching umbilical cord blood unit from an unrelated donor was used for high risk acute lymphocyte leukemia in third remmision. Following conditioning with busulfan, cyclophosphamide, and antithymocyte globulin (ATG), the patient underwent transplantation and attained sustained hemopoietic reconstitution without severe graft-versus-host disease. At 6 months following UCBT,he developed severe acute autoimmune hemolytic anemia associated with a “warm” IgG antibody. He was being treated with packed RBC transfusions, cyclosporine, steroids and immunoglobulins, His AIHA was partly resolved. Hemolysis recurred after steroid tapering and partially responded to rituximab (375 mg/m(2) once weekly ×4 and plasma exchange.Despite a range of complex treatment regimen, the unstable hemolytic anemia was present and repeated severe infectious episodes occurred.We reduced suppression,strengthened antibiotic therapy,Pulmonary infection and hemolysis could not be controlled, the patient died of respiratory failure and circulatory collapse finally. This case report highlights the difficulty in managing posttransplant AIHA,Further studies about the pathogenesis of AIHA associated in HSCT recipients are needed.