LAUSR

While emerging therapies such as gene therapy are being explored, allogenic hematopoietic stem cell transplantation (HSCT) remains the most established curative treatment for sickle cell anemia (SCA). Yet its application is limited by toxicity risks, donor availability, and socio-economic factors. In pediatric cases, myeloablative HSCT from an HLA-matched related donor (HLA-MRD), following either Busulfan or Treosulfan-based conditioning regimen yields SCA-free survival rates surpassing 90%, along with minimal occurrences of graft-versus-host disease (GVHD). 1 – 4 However, the optimal timing of transplantation remains debated due to concerns about fertility impairment, incidence of GVHD and transplant-related mortality at older ages. 2 While current literature suggests that outcomes generally improve with younger age (10 – 16 years), extensive toxicities associated with HSCT in SCA are not well-characterized. This analysis, aims to address this gap by providing a comprehensive assessment of acute toxicities associated with pediatric HSCT from HLA-MRD in the treatment of SCA, with a comparison between two age groups. This study included 97 SCA patients under 18 years of age who underwent HLA-MRD transplantation following myeloablative conditioning (MAC) regimen with antithymocyte globulin (ATG) between January 2005 and December 2019. Of these, 78 patients were under 13 years old, while 19 were aged 13 – 18 years. Median age at transplantation was 9 years [6; 12]. Patient and transplant characteristics are detailed in Table 1. The primary indications for HSCT were recurrent vaso-occlusive events, acute chest syndrome, and cerebral vasculopathy. Before transplantation, patients aged 13 – 18 years exhibited higher incidence of bacterial infections (68% vs. 35%, p = .01)