Fig. 1
The schematic diagram of conditioning regimen and prophylaxis and management of GVHD. Conditioning included 1 of 2 regimens: for patients with SAA-I (a), intravenous administration of fludarabine (Flu) 30 mg/(m2 day) and cyclophosphamide (Cy) 500–800 mg/(m2 day) from day − 5 to − 2, anti-human T-lymphocyte immunoglobulin (ATG) 5 μg/(kg day) from day − 4 to − 1; or for SAA-II (b), the same treatment of ATG and Cy with busulfan (Bu) 0.6 mg/(kg 6 h) from day − 7 to − 6. Prophylaxis and management of GVHD included: intravenous administration of cyclosporine A (CSA) 3 mg/kg from day − 5, followed by gradual decrease in concentration after reaching a target trough blood concentration of 250–450 ng/mL and then withdrawal in the next 2–3 months, oral mycophenolate mofetil (MMF) administration (20 mg/kg/day) from day − 1 to + 100, and intravenous anti-CD25 antibody (CD25Ab) monoclonal antibody (0.5 mg/kg/day) on day + 4 after HSCT. SAA-I: acute severe aplastic anemia, SAA-II: chronic severe aplastic anemia