Outcomes and risk factors of hemorrhagic cystitis in pediatric allogeneic hematopoietic stem cell transplantation recipients using different graft source and condition with severe aplastic anemia

Background: Hemorrhagic cystitis (HC) is a severe complication of allo-HSCT, characterized by irritative symptoms of the urinary tract and a higher morbidity rate. The risk factors and prognosis of HC are still unclear. Objective: The objective of this study is to identify risk factors and outcomes to improve treatment in pediatric SAA patients undergoing HSCTs in the Children's Hospital of Soochow University. Methods: A total of 97 SAA patients as a cohort were enrolled from 2010 to 2019 in the Children's Hospital of Soochow University and a number of factors related to HC and outcomes were analysed. In all transplants (except UCBT), patients received a combination of G-CSF stimulated bone marrow (BM) and peripheral blood stem cell (PBSC). The minimum number of CD34 + cells is 5 x 10(6) cells/kg. Results: Mononuclear cells dose (MNC, cut off: 8.53 x 10(8)/kg) and grade II-1V acute graft versus host disease (aGVHD) were identified as independent risk factors for HC. Patients without HC had better overall survival (OS) than with HC (No HC: 98.6%+/- 1.4% vs HC: 87.4% +/- 6.8%, p = 0.03). Conclusion: We concluded that aGVHD and MNC dose in graft might play an important role in the development of HC in pediatric SAA patients undergoing allo-HSCT. HC is also a key complication affecting the prognosis of children with SAA after alto-HSCT.