Effect of donor-recipient size mismatch on long-term graft survival in pediatric kidney transplantation: a multicenter cohort study

Background: Donor-recipient size mismatching is commonly occurs in pediatric kidney transplantation (KT). However, its effect on graft survival remains unknown. This study aimed to determine the effect of donor-recipient size mismatch on the long-term survival rate of transplant kidneys in pediatric KT. Methods: A total of 241 pediatric patients who received KT were enrolled. The medical records of all patients were retrospectively re-viewed, and the correlation between donor-recipient size mismatch and graft function and long-term graft outcome was analyzed ac-cording to donor-recipient size mismatch. Results: Recipients and donors' mean body weight at the time of KT were 34.31 +/- 16.85 and 56.53 +/- 16.73 kg, respectively. The mean follow-up duration was 96.49 +/- 52.98 months. A significant positive correlation was observed between donor-recipient body weight ratio (DRBWR) or donor-recipient body surface area ratio (DRBSR) and graft function until 1 year after KT. However, this cor-relation could not be confirmed at the last follow-up. The results of long-term survival analysis using Fine and Gray's subdistribution hazard model showed no significant difference of the survival rate of the transplant kidney according to DRBWR or DRBSR. Conclusion: Donor-recipient size mismatch in pediatric KT is not an important factor in determining the long-term prognosis of trans-plant kidneys.