Long-term outcome of kidney transplantation in patients with congenital anomalies of the kidney and urinary tract

Background Congenital anomalies of the kidney and urinary tract (CAKUT) are a leading cause of end-stage kidney failure in the young. However, there is limited information on long-term outcomes after kidney transplantation in this group. We explored the outcomes of kidney transplant in patients with the 3 most common severe forms of CAKUT: posterior urethral valves (PUV), reflux nephropathy and renal hypoplasia/dysplasia. Methods Data were extracted from the Australian & New Zealand Dialysis & Transplant Registry on first kidney transplants performed between 1985 and 2015 in recipients with a primary diagnosis of PUV, renal hypoplasia/dysplasia or reflux nephropathy (under the age of 30 years). Using multivariate Cox regression, we compared death-censored graft survival between the three groups. Results One hundred twenty-seven patients with PUV, 245 with hypoplasia/dysplasia and 727 with reflux nephropathy were included. A 10-year graft survival in PUV, hypoplasia/dysplasia and reflux nephropathy was 70%, 76% and 70%, respectively and a 20-year graft survival was 30%, 53% and 49%. After adjusting for age at transplant, graft source and HLA matching, there was evidence for poorer graft survival in PUV (HR, 1.65; 95% CI, 1.15 to 2.38). Conclusions Graft survival of the first transplant in CAKUT is favourable at 10 years; however, recipients with PUV have increased risk of graft loss beyond a 10-year post-transplant, which may be related to bladder dysfunction.