Kidney Transplantation in Nephropathic Cystinosis: Outcomes in The 21ST Century.

Abstract

Background: Nephropathic cystinosis (NC) is an autosomal recessive, lysosomal storage disease affecting about 500 individuals in North America. Presenting in infancy with Fanconi syndrome and growth retardation, long term complications include renal failure, myopathy, diabetes, and CNS deterioration. With the advent of cysteamine therapy, life expectancy has improved and the need for renal replacement therapy delayed into adolescence. While prior studies of NC recipients have shown better patient and graft survivals compared to non-NC recipients, these studies were primarily in pediatric recipients, using non-contemporary immunosuppression. The goal of this study was to investigate the impact of older recipient age and current transplant practices on outcomes in NC recipients. Methods: Kidney-only recipients with a primary diagnosis of NC from SRTR 2003-2013 [n=200] were matched to general kidney-only recipients (1:1) based on age, race, gender, pre-emptive transplant status, donor type (living or deceased), and re-transplantation. Death-censored graft survival (DCGS) and patient survival (PS) were estimated using Kaplan-Meier and compared using log-rank and Cox models (Hazard Ratio [HR]). Results: Among recipients with NC, the median age at transplant was 17y (range: 13-27y). 51% were male and 84% Caucasian, reflecting the genetic preponderance of the disease. 56% received living donor transplants, 45.5% were transplanted pre-emptively before dialysis, and 22% underwent re-transplant. Compared to the general recipient population, there was no statistically significant difference in DCGS [10yr NC 64.2% vs. non-NC 46.3%, p=0.71; HR 0.75, 95% CI 0.41-1.38, p=0.36] (A). However, NC recipients demonstrated a trend toward significantly lower PS [10yr NC 83.4% vs. non-NC 92.5%, p=0.076] (B) and a 3-fold increased risk for patient death [HR 3.0; 95% CI 0.97-9.30 p=0.06].Figure: No Caption available.Conclusion: While prior studies have shown improved outcomes in recipients with NC, our data indicate that long term patient survival is worse in NC recipients. This may reflect the later complications of cystinosis, and mandates a transition of care to adult centers that includes a management plan for cystinosis. DISCLOSURES:Mannon, R.: Other, Raptor, Advisory Board Member.