Early Urinary Complications in Renal Transplantation: A Potential Risk Factor for Allograft Rejection

Abstract

Objective: A recently debated and poorly understood mechanism involving immunologic activation by bacterial infection among recipients of abdominal allografts has been proposed. Specific to the topic of renal transplantation are the contributions of urinary tract infections (UTIs) and acute graft pyelonephritis (AGPN) to this hypothesis. We sought to further investigate the contribution of early urinary complications on renal transplant allograft failure. Methods: A single institution retrospective analysis of primary renal transplants was conducted to identify the incidence of early urinary complications (within one year post-transplant) and determine their effects on allograft survival. All identified urinary strictures/stenoses as well as leaks not requiring surgical or endourologic intervention were excluded from our study. Immunologic risk factors (CMV/BK polyoma viremia,induction/maintenance immunosuppression, HLA data, peak PRA) were reviewed and analyzed. A time-varying covariate was constructed using the presence of a urologic complication(s) post-transplantation to investigate its effect on renal allograft survival. Results: 3902 primary renal transplants were performed from January 1995 to December 2010. Of those organs transplanted, 59.4% were from cadaveric donors. 125 (3.2%) patients had a urinary stricture while 62 (1.6%) had a urinary leak. 1253 patients had > 2 UTIs during the overall cohort study period of which 32.1% occured within the first year. Presence of Cytomegalovirus (CMV) Viremia (HR 1.66, P < 0.0001), BK polyoma Viremia (HR 1.62, P < 0.0001) and > 2 UTIs (HR 1.85, P < 0.0001) within the first year post-transplant were identified as significant risk factors associated with decreased allograft survival. Urinary strictures (HR 1.26, p 0.085) trended toward but were not found to be statistically significant.Table: [Postoperative Urinary Complication Data]Table: [Urologic Disease/Risk Factors]