Impact of the pretransplant dialysis modality and duration on pediatric kidney transplant outcomes: a comparison between hemodialysis and peritoneal dialysis.

AIMS/PURPOSE Kidney transplantation is the treatment of choice for pediatric patients with end-stage kidney disease; however, pre-emptive transplantation remains limited due to donor shortage. Consequently, most children require renal replacement therapy while awaiting transplantation, either peritoneal dialysis or hemodialysis. The impact of dialysis modality on transplant outcomes remains unclear, with limited and conflicting pediatric data. This study aimed to evaluate differences in post-transplant outcomes according to dialysis modality (renal function, rejection episodes, development of donor-specific antibodies and graft failure). Furthermore, as a secondary outcome, the study will evaluate and compare the impact on quality of life between the two dialysis modalities and kidney transplantation. METHODS This single-center retrospective observational study included 187 pediatric patients who underwent kidney transplantation at the Hospital of Padova between 2007 and 2023. All patients received dialysis prior to transplantation: 85 peritoneal dialysis, 68 hemodialysis, and 33 both modalities. Post-transplant outcomes were evaluated using clinical, laboratory, immunological, and histological data collected at 6, 12, and 24 months and at last follow-up. Protocol biopsies were performed and classified according to Banff 2015 criteria, and anti-HLA antibodies (DSA and non-DSA) were assessed For the quality-of-life assessment, a questionnaire has been developed and will be administered to a subgroup of patients in the coming months. RESULTS The study population included 187 pediatric kidney transplant recipients (67 females, 119 males), median age at transplantation of 11.5 years (IQR 4.9 -16.4). Age and body weight at transplantation differed significantly among groups (p<0.0001), with higher values in HD patients, who also showed a higher rate of retransplantation (p<0.05), while other baseline characteristics were comparable. At univariate analysis, dialysis modality was not associated with eGFR at 6, 12, or 24 months post-transplant (p=0.29, p=0.41, and p=0.17, respectively). Similarly, no significant differences were observed in histological findings based on Banff classification at any time point (p=0.98, p=0.17, and p=0.37). Consistently, at multivariate analysis, dialysis modality was not independently associated with eGFR at 6, 12, or 24 months. In contrast, transplant type was significantly associated with eGFR at 12 and 24 months, while ATG use and number of transplants emerged as additional predictors at 24 month. CONCLUSIONS In conclusion, our study suggests that pre-transplant dialysis modality does not significantly influence early and mid-term post-transplant outcomes in pediatric kidney transplant recipients. Instead, transplant-related and immunological factors remain the main determinants of graft function, supporting a patient-centered approach in the selection of dialysis modality prior to transplantation.