Backgrounds: Timing of kidney transplantation (KTx) for infants with congenital nephrotic syndrome (CNS) is an important issue. KTx is rarely performed in CNS infants < 1 y of age due to their limited abdominal space for an adult-sized kidney. They have to wait for some months or years to reach a bigger size before a KTx. However, long-term dialysis in these young infants with severe hypoalbuminemia remains challenging, with increased mortality, higher risk of infection, and poor growth.
Methods: From June 2017 to July 2019, a total of 4 infants with CNS (Finnish type) received single KTx before the initiation of dialysis. The smallest recipient was at the age of 2 months and 26 days (weighting 3.5 kg), while the oldest patient was 7-month old with a body weight of 5.5 kg (Table 1). All renal grafts were donated from deceased infant donors (2.7 to 5 kg in weight). A single kidney was implanted intraperitoneally with anastomosis to the recipient’s aorta/vena cava after the procedure of bilateral nephrectomy. The immunosuppressive regimen was as follows: induction therapy with rATG except for the first infant; maintenance therapy with cyclosporine (i.v. pump) for 1-2 weeks, followed by oral tacrolimus and MMF; steroids tapering and weaning.
Results: DGF occurred in 3 of the 4 recipients, 2 of whom recovered respectively after 5 and 16 times of CRRT, and 1 lost the transplanted kidney due to biopsy-proved acute mixed rejection during the period of DGF (Table 1). The infant with graft failure received a second renal graft which was implanted in the left ilium fossa with anastomosis to the external iliac vessels, and the graft function recovered smoothly. None of these patients had urine leakage, acute rejection and proteinuria during the follow-up of 6 to 31 months. The eGFR at the last follow-up was 55-110 ml/min/m2. In addition, the recipient infants were growing very well.
Discussions: In a small group of young CNS infants with severe proteinuria, we have demonstrated, for the first time that it is feasible to perform preemptive KTx with simultaneous bilateral nephrectomy by using size-matched small infant donors. Long-term results will need further follow-up observation.
Conclusions: Good clinical outcome can be achieved without the need to postpone KTx for infants with CNS.