Cadaver renal transplantation in children with cystinosis

Five children with end-stage renal disease resulting from cystinosis received seven cadaver renal allografts. Four recipients have functioning grafts eight to 55 months after receiving the transplant and one recipient lost two grafts at 17 and 26 months after the transplant. There was no florid recurrence of the Fanconi syndrome although proximal renal tubular dysfunction developed in two patients, in one in association with chronic rejection and in one without apparent etiology. Free cystine content of white blood cells, cultured skin fibroblasts and allograft tissue was significantly increased. Cystine crystals were observed in the mesangium of two grafts and in the interstitial tissue of all grafts; however, no cystine crystals were found in the tubules. The location of the cystine crystals, as well as the fact that the highest free level of cystine of allograft tissue was observed in the graft undergoing chronic rejection, led to the hypothesis that recipient cells infiltrating the graft were the source of cystine deposition. The data indicate that successful cadaveric transplantation does not correct the primary metabolic defect in cystinosis, thereby explaining the persistence of the extrarenal clinical manifestations, such as photophobia and hypothyroidism, after renal transplantation in cystinosis.