[Treatment strategy for acquired aplastic anemia].

"The guidelines for the diagnosis and treatment of aplastic anemia (AA) in Japan" have recently been revised. Former stage 2 has been divided into stage 2a, which does not require red blood cell (RBC) transfusions, and stage 2b, which requires <2 units of RBC transfusions per month. In addition, the guidelines recommend treating stage 2b similar to stages 3 or higher severity. The standard immunosuppressive therapy for transfusion-dependent AA has been changed from ATG plus cyclosporine (CsA) to ATG+CsA+eltrombopag. For patients with stage 1 and stage 2b AA, initiating CsA as early as possible after the diagnosis is recommended. Notably, high-dose (200 mg/kg) cyclophosphamide (CY), which has been used as the standard conditioning regimen for allogeneic stem cell transplantation (SCT), is less frequently used than a reduced-dose CY regimen that contains fludarabine for avoiding cardiotoxicity. Among transplant regimens from alternative donors, HLA-haploidentical SCT from related donors using post-transplant CY is presently garnering recognition because of its low transplant-related mortality and the low incidence of chronic GVHD.