Long-Term Outcomes of Renal Transplantation in Patients with Cystinosis.

Abstract

Background and aims: Cystinosis is a rare autosomal recessive lysosomal storage disorder caused by mutations in the CTNS gene, leading to cystine accumulation and progressive multisystem involvement. Renal failure is the clinical outcome, and renal transplantation markedly improves survival. However, long-term post-transplant outcomes remain limited. This study aimed to evaluate long-term graft and patient outcomes in cystinosis patients undergoing renal transplantation.

Methods and results: This single-center retrospective case series included 6 male patients with cystinosis who underwent renal transplantation during childhood. The mean age at diagnosis was 3.9 years, and the mean follow-up period after transplantation was 12.3 years. Five patients received kidneys from living donors and one from a deceased donor. All patients were treated with cysteamine. No graft loss was observed during follow-up, and renal function remained stable in all patients. One patient developed antibody-mediated rejection while on cyclosporine, whereas no rejection episodes occurred in patients receiving tacrolimus-based regimens. Extrarenal involvement was predominantly ocular, with occasional thyroid, skeletal, and cardiac manifestations. Growth retardation was evident in all patients despite treatment.

Conclusion: Renal transplantation provides excellent long-term graft and patient outcomes in cystinosis. Favorable graft survival, even in the presence of HLA mismatch, suggests a potentially protective disease-related effect. Early diagnosis, timely transplantation, and continued cysteamine therapy are essential for optimal long-term outcomes.