Background: For infants with end stage renal disease or congenital nephrotic syndrome (CNS), kidney transplantation (KTx) can be challenging due to surgical technique and incidence of post-transplant complications. The aim of our study was to evaluate the outcomes of infant recipients aged <2 years at KTx, when using size-matched kidney grafts from deceased infant donors.
Methods: A retrospective cohort study was conducted on infants who underwent KTx at an age <2 y, compared to a control group with an age of 2-5 y at the time of KTx, during June 2017 and August 2024. Both groups received KTx from deceased pediatric donors at similar body weights.
Results: A total of 49 cases of renal transplantation were performed in 45 patients at 0-5 years of age during the study period in our center, including 30 cases were recipients aged <2 y. Mean body weight at KTx was 7.3±2.1 kg in <2 y group and 11.4±1.9 kg in 2-5 y group, respectively. Mean age was 1.04±0.49 y and 2.64±0.34 in the two groups. CNS was the most common native kidney disease, consisting of 70% and 47.4% of all causes in <2 y group and 2-5 y group, respectively. Genetic mutation was found in 86.7% of <2 y group and 84.2% of 2-5 y group. Small infant recipients were more likely to receive a pre-emptive transplant (41.4% vs 21.1%, p=0.21) and simultaneous bilateral native kidney nephrectomy during transplantation (60% vs 31.6%, p=0.07). Grafts were implanted intraperitoneally in 18 cases (60%) in <2 y group and 5 (26.3%) in 2-5 y group. Median donor age was slightly higher in 2-5 y group (1 y vs 0.79 y, p=0.18), similar to the difference in median donor weight (8.2 kg vs 7 kg, p=0.21). Median follow-up time was 36.5 (8-92) months in <2 y group and 38 (4-87) months in 2-5 y group. The overall incidences of surgical complications (<2 y group 23.3% vs 2-5 y group 15.7%, p=0.72) and acute rejection episodes (<2 y group 23.3% vs 2-5y group 21.1%, p=1.0) were not significantly different between the groups (Table 1). Besides, recipients in <2 y group were more prone to urinary tract infection than 2-5 y group (33.3% vs 5.3%, p=0.03). Median estimated glomerular filtration rate (eGFR) at 1-year and 3-year post-transplantation were excellent in both groups and showed no significant difference (<2 y group 96.8 ml/min/1.73m2 vs 2-5 y group 89.5 ml/min/1.73m2 at 1 year, p=0.33; 85.0 ml/min/1.73m2 vs 93.9 ml/min/1.73m2 at 3-year, p=0.31). Graft survival rates at 1-year and 3-year for <2 y group and 2-5 y group were 86.7% and 94.7% respectively (p=0.38). Same patient survival rates of 94.7% were observed in two groups at 3-year post-transplantation.
Conclusions: Kidney transplantation for small infants aged <2 y from deceased pediatric donor is a feasible option, with satisfying graft and patient survival, without significantly elevated incidence of surgical complications.