Progressive ischemic chronic renal allograft injury in an infant with an adult-sized kidney transplant : observations over one decade

[SUMMARY] Kidney transplantation（KTx）in infants（body weight［BW］ ＜10 kg and/or body surface area［BSA］ ＜0.5 m2）is an accepted treatment option for chronic kidney disease in children and has demonstrated excellent short-term graft survival. However, follow-up studies longer than five years are still lacking. We experienced a case of an infant（BW 9.2 kg, BSA 0.44 m2）with an adult-sized kidney（ASK）transplant（donor-recipient height ratio : 2.24）which resulted in graft loss at 9.7 years after the transplant secondary to biopsy-proven chronic allograft ischemia（CAI）. Intensive maintenance fluid supplementation failed to prevent ongoing and long-standing graft hypoperfusion. While the decrease in the estimated glomerular filtration rate（eGFR）was irregular, the progression of chronic changes seen in the graft biopsies was linear, both in early- and late-phase KTx. CAI in significantly size-mismatched ASKs transplanted into infants can promote late graft failure within ten years. Since serial evaluations of renal histology were shown to be a better indicator of renal graft outcomes throughout the post-transplant course, transplant surveillance biopsies beyond the early phase of KTx may assist in elucidating the natural course of CAI in ASKs transplanted into infant recipients.