Renal Transplants Due to Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) Have Better Graft Survival Than Non-CAKUT Controls: Analysis of Over 10,000 Patients

Objective: To determine whether graft survival for patients with congenital anomalies of the kidney and urinary tract (CAKUT) is impaired compared to non-CAKUT counterparts.

Methods: The United States Renal Data System (USRDS) is a national data system that has collected information about end stage renal disease (ESRD) and renal transplantation since 1995. We identified 10,635 first-time renal transplant patients with ESRD attributed to a CAKUT diagnosis transplanted between 1995 and 2018, with follow-up of 7.9 ± 5.8 years. We matched 1:1 with non-CAKUT transplant recipients, using age at transplant, sex, race, year of transplant, and donor-type. We compared renal transplant death-censored graft survival between CAKUT vs non-CAKUT controls, with further stratification for age at transplant and lower urinary tract malformations (LUTM) vs upper urinary tract malformations (UUTM).

Results: Graft survival was better in CAKUT patients with a 5-year survival of 83.3% vs 79.3% (P< .001), and CAKUT status infers a hazard ratio of 0.878 for graft failure on multivariable analysis with Cox regression. Favorability of CAKUT status persisted when stratifying for both pediatric (80.3 vs 77.6% P< .001) and adult (84.5 vs 81.4% P< .001) age groups. Looking within the CAKUT population: comparison of LUTM to UUTM yielded no difference, implying that LUTM is not a risk factor for graft failure. Examining pediatric LUTM alone, graft survival was not better than matched non-CAKUT counterparts with 5-year graft survival of 69%-75% for LUTM adolescents.

Conclusion: Renal transplant graft survival is better overall in CAKUT patients as opposed to non-CAKUT counterparts. Pediatric LUTM patients have similar graft survival to controls.