Definitions
OS was measured from the first day of IST until death or the date last known alive. Relapse was defined as reduced blood counts that warranted the reintroduction of full-dose CSA. Clonal evolution was defined as progression to myelodysplastic syndrome and acute myeloid leukemia. A PNH clone was considered present if glycophosphatidylinositol hemocytes exceeded 5% according to flow cytometry data. EFS was measured from the start of IST until an event (death, relapse, clone evolution or start of a second therapy for aplastic anemia, either hematopoietic stem cell transplantation or a second course of IST). CR was defined with a bone marrow sample showing <5% myeloblasts with normal maturation of all cell lines and no dysplasia, peripheral blood neutrophil count ≥1×109/L, hemoglobin ≥10 g/dL, and platelet count ≥100×109/L. Partial response (PR) was reflected by transfusion independence and G-CSF with ANC ≥0.5×109/L, hemoglobin ≥8g/dL, and platelet count ≥20×109/L. OR was defined as at least a PR (PR+CR). No response (NR) was defined as failure in any lineage. These definitions have been previously reported [17]. Response time referred to the time from IST to the first objective response.