Polyuria and proteinuria in cystinosis have no impact on renal transplantation

Abstract

Because cystinotic patients are polyuric and may have severe proteinuria, each of which is a potential risk factor for graft thrombosis, preemptive transplantation for them is questionable. The objectives of this study were to characterize the changes in urine volume and protein excretion at various stages of cystinosis, determine whether there is serologic evidence of hypercoagulability, and review the clinical experience in renal transplantation in cystinotic children. The records of cystinotic patients followed at the Montreal Children's Hospital between 1992 and 1998 were reviewed. Urinary volume, protein excretion, and coagulation markers were collected to determine the glomerular filtration rate (GFR) >50 ml/min/1.73 m2, <20 ml/min/1.73 m2, before and after starting dialysis. In addition, graft failure and graft thrombosis rates were obtained from the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) database. Urinary volume and protein excretion remained elevated throughout different phases of the disease. Coagulation factors were within normal limits for all patients. In the NAPRTCS database there were four thromboses among the 114 patients transplanted cystinotic patients. All these occurred in cadaveric grafts and only one occurred after preemptive transplantation. Despite polyuria and severe proteinuria, children with cystinosis do not appear to be at an increased risk of graft failure or graft thrombosis.

The History of Cystinosis: Lessons for Clinical Management

“…In untreated cystinotics, multinucleated podocytes are seen in glomeruli [12, 13], and tubular proteinuria is overshadowed by progressive focal segmental glomerulosclerosis associated with nephrotic-range proteinuria and progressive renal insufficiency [14]. By 1974, this prognosis had not changed much, leading Royer to remark in his textbook of Pediatric Nephrology that children with cystinosis usually survive until the age of about 10–12 years, when they succumb to end-stage renal failure [15].…”

“…As cystinotics develop end-stage renal disease, they may have heavy proteinuria and high urine volumes. However, the incidence of graft thrombosis is not different than that in the general population, and children are accustomed to drinking large volumes prior to transplantation [14]. Thus, it is not entirely evident that they need pretransplant nephrectomise, and this decision should be approached carefully.…”

Staged Hand-Assisted Bilateral Native Nephrectomy for Management of Posttransplant Polyuria in an Adult with Dent’s Disease

“…Severely polyuric patients may also be at increased risk of transplant renal artery and/or vein thrombosis [ 3 ]. However, there may be additional contributory factors beyond polyuria itself, as patients with polyuria secondary to cystinosis do not have worse graft outcomes [ 4 ] nor have worse graft outcomes been previously reported in patients with Dent's disease. Persistent polyuria in this patient led to significant difficulty maintaining fluid balance following transplantation, resulting in accelerated loss of his first allograft and threatening his second allograft.…”