Effect of urinary tract infection on the outcome of the allograft in patients with kidney transplantation.

Background: Urinary tract infections (UTIs) are the second most common cause of graft dysfunction, accounting for significant morbidity, and are associated with poor graft and patient survival. This study aimed to assess the association between post-renal transplant UTI and graft outcomes.

Methods: We examined the effect of UTIs on graft outcomes in patients who underwent renal transplantation surgery between January 2010 and December 2022. The study population included 349 renal transplantations, of which 74 experienced 140 UTI events. Based on the number of UTI episodes, patients were categorized into three groups.

Results: Of the 349 recipients, 275 (74.4%) had no UTI, 47 (18.8%) had non-recurrent UTIs (NR-UTIs), and 27 (6.8%) had recurrent UTIs (R-UTIs). Kaplan-Meier survival analysis showed that post-KT UTI status was a significant factor in graft survival, death-censored graft survival, and patient survival after a follow up of 5 years (log rank, P < 0.001). R-UTIs were associated with very poor graft survival and patient survival when compared with no UTI after a follow up of 5 years (hazard ratio [HR], 1.506; 95% confidence interval [CI], 1.233-1.840; P < 0.001 & HR, 1.529; 95% CI, 1.227-1.905; P = 0.001). R-UTIs were more likely to be associated with multi-drug resistant Gram-negative organisms (Klebsiella pneumonia or Escherichia coli) with resistance to nitrofurantoin (RR, 2.753; 95% CI, 1.257-6.032; P = 0.01) and carbapenem (RR, 2.064; 95% CI, 0.988-4.314; P = 0.05).

Conclusion: Compared to no UTI, R-UTIs were associated to worse graft and patient outcomes after a follow-up of 5 years, whereas NR-UTIs were associated with poor graft and patient outcomes in the long term.