A new treatment for infants with congenital nephrotic syndrome: pre-emptive kidney transplantation along with simultaneous bilateral nephrectomy

Backgrounds: For infants with end stage renal disease (ESRD), kidney transplantation is generally recommended upon a body weight of ≥10 kg. However, infants with congenital nephrotic syndrome (CNS) presenting with severe proteinuria and hypoproteinemia but have not yet progressed to ESRD are placed at higher risks of malnutrition, infection, thrombosis, and even mortality while awaiting transplantation. This study aimed to evaluate the safety and analyze the outcomes of pre-emptive kidney transplantation combined with simultaneous bilateral nephrectomy for CNS infants.
Methods: The cohort included 27 infants who underwent kidney transplantation at an age <2 years at Tongji Hospital from June 2017 to February 2025. Thirteen of them were CNS infants with an eGFR >35mL/min/1.73m2 at the time of transplantation (the early transplant group); the remaining 14 infants had progressed to ESRD with eGFR <15 mL/min/1.73m2 (the late transplant group). Outcomes were compared between the two groups.
Results: Median follow-up time was 43 and 47.5 months for the early transplant group and the late transplant group, respectively. Despite significantly lower body weight (6.4±2.4 vs 8.4±1.5 kg, p<0.05) and younger age (0.7±0.4 vs1.3±0.3 years, p=0.002) at transplantation compared to the late transplant group, the early transplant group achieved comparable excellent mid-term outcomes. The 3-year graft survival (84.6% vs. 85.7%) and patient survival (91.6% vs. 100%) rates were comparable between the groups. A higher eGFR was observed in the early transplant group (93.8 mL/min/1.73m² vs. 84.8mL/min/1.73m²) by 3 years post-transplant. Meanwhile, a significant catch-up growth was also observed in the early transplant group, whose mean height SDS was lower than that in the late transplant group before transplantation (-3.44 vs -1.93), and then caught up to level comparable to the late transplant group (-0.49 vs -0.58). Same trend was observed in weight SDS. In addition, serum total protein and albumin levels before transplantation were significantly lower in the early transplant group than in the late transplant group (p < 0.0005), the difference was rapidly eliminated by 6 months post-transplant. Besides, except for CMV viremia which was more common in the early transplant group (p = 0.05), the incidence rates of other infection episodes showed no significant differences between the two groups. Acute rejection was more frequently observed in the late transplant group. More importantly, the incidence of surgical complications showed no significant differences between the two groups.
Conclusions: For infants with CNS, an early pre-emptive kidney transplantation with nephrectomy can achieve comparable mid-term outcomes with better graft function and catch-up growth compared to the infants with late transplantation.