Successful HLA-haploidentical peripheral blood stem cell transplantation with posttransplant cyclophosphamide for refractory pediatric acute myeloid leuekmia after repeated Viridans streptococcal sepsis

Abstract

 We herein describe a 7-year-old male with refractory acute myeloid leukemia who relapsed 9 months after bone marrow transplantation from human leukocyte antigen (HLA) -identical sibling. He received 2 cycles of FLAG chemotherapy, however, complete remission was not obtained. In addition, sepsis due to viridans group streptococci occurred in 2 of 2 courses of chemotherapy. He underwent haploidentical peripheral blood stem cell transplantation (haploPBSCT) from his father. The conditioning regimen consisted of fractionated total body irradiation (9.9 Gy) and fludarabine (120 mg/m²). Tacrolimus, mycophenolate mofetil, and posttransplant cyclophosphamide (PTCy) (50 mg/kg×2) were administered for the prophylaxis of graft versus host disease (GVHD). The patient developed a fever on day 1, which was promptly resolved with PTCy. On day 18, myeloid engraftment was achieved. The patient developed grade I acute GVHD and mucositis. A fourth CR was obtained for 1 month after haploPBSCT. On day 180, he has been in continuous remission while maintaining his quality of life (QOL). Although the use of haploPBSCT with PTCy has been limited in children, this strategy may be potentially less toxic and helpful to maintain or improve the QOL of patients.