The impact of donor-recipient sex matching on transplant-related complications in children after allogeneic haematopoietic stem cell transplantation – a single-centre, retrospective study

Introduction
Allogeneic haematopoietic stem cell transplantation (HSCT) is a well-established therapeutic option used in the treatment of malignant and non-malignant disorders. According to numerous studies, there is a correlation between donor sex or sex mismatching between donor and recipient and increased risk of graft-versus-host diseases.

Aim of the study
The aim of this study was to assess the impact of donor-recipient sex mismatching on the incidence of transplant-related complications in children undergoing allogeneic HSCT.

Material and methods
We conducted a retrospective study comparing the prevalence of transplant-related adverse events between female donor – female recipient, female donor – male recipient, male donor – male recipient, and male donor – female recipient groups. The study population included 198 patients from the department’s database, who underwent allogeneic HSCT between 2001 and 2018 in the Department of Paediatric Haematology, Oncology, and Transplantology in Lublin.

Results
No statistically significant differences in prevalence of transplant-related complications between the four groups were found in this study: acute graft-versus-host disease (p = 0.53), chronic graft-versus-host disease (p = 0.69), hepatic veno-occlusive disease (p = 0.41), renal failure (p = 0.81), bleeding (p = 0.51), cytomegaly virus infection (p = 0.41), Epstein-Barr infection (p = 0.29), and fungal infection (p = 0.31).

Conclusions
The study showed no correlation between sex mismatching and HSCT complication frequency in children. The results of this study suggest that the donor’s gender might not be a crucial factor in screening for potential donors in the paediatric population. Rising evidence of the lack of a direct impact of a donor’s gender on overall HSCT transplant outcomes and adverse events in the paediatric population might in future change the criteria we follow when looking for potential donors. In conclusion, there is a need for prospective observational studies, which could investigate the mechanisms of adverse events and multicentre retrospective studies, which would allow larger homogeneous populations to be gathered to further research the impact of donor’s demographics on allogeneic HSCT outcomes and complications.