Lack of Impact of Acute Pyelonephritis on Kidney Graft Survival

Urinary tract infection is the most common bacterial infection after kidney transplant. Some studies suggested that urinary tract infection could impair graft survival, but this issue remains debated. The objective of this study was to analyze the association between acute pyelonephritis (APN) and the risk of kidney graft failure.

We performed a retrospective cohort study including patients who received a kidney transplant from 2001 to 2009 at a university hospital in Rio de Janeiro, Brazil. They were followed until December 2015. The primary outcome was graft failure. Follow-up of patients who died with a functioning graft was censored on the date of death. Cox proportional hazards method was used in multivariable analysis to assess risk factors for graft failure. The occurrence of the first episode of APN and acute rejection were modeled as time-dependent variables.

A total of 587 patients were included. Of these, 112 recipients (19%) developed 173 episodes of APN. Graft failure occurred in 150 patients (25%) after a median follow-up of 79 months. The factors associated with graft failure in the multivariate analyses were age of the transplant recipient (hazard ratio [HR], 0.97 per year; 95% confidence interval [CI], 0.96-0.99; P < .01), occurrence of delayed graft function (HR, 2.42; 95% CI, 1.72-3.40; P < .01), and acute rejection (HR, 2.71; 95% CI, 1.92-3.82; P < .01). There was no association between APN and graft failure (HR, 1.05; 95% CI, 0.65-1.68; P = .85).

Our results suggest that the occurrence of APN is not associated with a significant reduction in graft survival after kidney transplant.