Succesful Treatment with Sirolimus in a Refractory Case of Pure Red Cell Aplasia (PRCA).

A patient with severe anemia since her birth was established a diagnosis of PRCA. Bone marrow aspirate showed an absence of red cell lineage, with lymphocyte hyperplasia. She was initiated with high dose of steroids without response. Two cycles of antithymocyte globulin (ATG) was administered, the first ATG 30mg/kg/5d with short response mainly evidenced by reticulocyte count, the second was established as ATG 15mg/kg/5d plus cyclosphosphamide 120mg/kg with a very transitory response. In November 2002 a Cord Blood Transplant was done, with a conditioning regimen based in Busulphan plus Cyclophosphamide and a prophylaxis for GVHD based on Cyclosporine plus Methylprednisolone. After a very rapid hematopoyesis recovery was discharged, but with no evidence of engraftment and autologous hematopoietic recovery, she received red cell transfusions monthly for about 36 months until December 2004 with desferroxamine as chelating drug. In December 2004 she started with Sirolimus 1mg a day orally with a very impressive response, red cells, hemoglobin levels, hematocrit, reticulocyte count improvement until normal levels. Red Cell transfusions were discontinued and two years later Sirolimus was also discontinued. She is in a very good Health Condition without any treatment in the last 8 months. We report this case in order to inform this successful treatment and in the order to use the same therapy in other cases.