Fig. 1

Study design. Hematopoietic stem cell transplantation comprises two phases. In phase I, patients that fulfill the inclusion criteria for transplantation are thoroughly evaluated for organ involvement, eligibility and exclusion criteria (baseline evaluation). Then, progenitor hematopoietic cells (CD34+) are mobilized from the bone marrow to the peripheral blood by a regimen of cyclophosphamide plus granulocyte-colony stimulating factor (G-CSF). Circulating CD34+ cells are harvested from the peripheral blood through apheresis and cryopreserved, without further manipulation. In phase 2, which begins at least 2 weeks after phase 1, patients are treated with a conditioning regimen consisting of combined high-dose chemotherapy and immunotherapy agents, usually cyclophosphamide 200 mg/kg plus anti-thymocyte globulin (ATG). Subsequently, the previously harvested autologous progenitor cells are thawed at bedside and administered to the patient, intravenously. A period of bone marrow aplasia follows, lasting approximately 7 days, ended by hematological and immunological recovery. Patients are followed-up periodically for hematological and immunological reconstitution and clinical outcomes, until 5-years of follow-up