Polyuria and proteinuria in cystinosis have no impact on renal transplantation - A report of the North American Pediatric Renal Transplant Cooperative Study

Because cystinotic patients are polyuric and may have severe proteinuria, e ach of which is a potential risk factor for graft thrombosis, preemptive tr ansplantation for them is questionable. The objectives of this study were t o characterize the changes in urine volume and protein excretion at various stages of cystinosis, determine whether there is serologic evidence of hyp ercoagulability, and review the clinical experience in renal transplantatio n in cystinotic children. The records of cystinotic patients followed at th e Montreal Children's Hospital between 1992 and 1998 were reviewed. Urinary volume, protein excretion, and coagulation markers were collected to deter mine the glomerular filtration rate (GFR) >50 ml/min/1.73 m(2), <20 ml/min/ 1.73 m(2), before and after starting dialysis. In addition, graft failure a nd graft thrombosis rates were obtained from the North American Pediatric R enal Transplant Cooperative Study (NAPRTCS) database. Urinary volume and pr otein excretion remained elevated throughout different phases of the diseas e. Coagulation factors were within normal limits for all patients. In the N APRTCS database there were four thromboses among the 114 patients transplan ted cystinotic patients. All these occurred in cadaveric grafts and only on e occurred after preemptive transplantation. Despite polyuria and severe pr oteinuria, children with cystinosis do not appear to be at an increased ris k of graft failure or graft thrombosis.