Incidence of and Risk Factors for Recurrent Urinary Tract Infections in Renal Transplant Recipients

BACKGROUND: Recurrent urinary tract infections (rUTIs) are common after renal transplantation (RTx), and the impact on graft and patient survival remains controversial. OBJECTIVE: In this study, we investigate the incidence and risk factors for rUTIs in a cohort of RTx recipients and evaluate the effect on graft and patient survival. DESIGN, SETTING, AND PARTICIPANTS: A retrospective cohort of adult patients who underwent RTx at Rigshospitalet, Denmark, between 2014 and 2021 was evaluated in this study. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Risk factors for rUTIs were explored with a multivariable cause-specific Cox proportional hazard analysis. The Kaplan-Meier estimate was used to assess overall survival. RESULTS AND LIMITATIONS: A total of 571 RTx recipients were included. The median age was 52 yr (interquartile range: 42–62 yr). Of the cases, 62% were deceased donor RTx. A total of 103 recipients experienced rUTIs. We found increasing age (hazard ratio [HR]: 1.02 per year increase, 95% confidence interval [95% CI]: 1.00–1.04, p = 0.02), female gender (HR: 2.1, 95% CI: 1.4–3.3, p < 0.001), history of lower urinary tract symptoms (HR: 2.3, 95% CI: 1.4–3.5, p = 0.001), and a UTI within 30 d of surgery (HR: 3.5, 95% CI: 2.1–5.9, p < 0.001) were associated with rUTIs. No influence of rUTIs on overall or graft survival was observed. CONCLUSIONS: One in six patients experience rUTIs after RTx. Pre- and postoperative variables affect the risk of rUTIs, but none are easily modifiable. In this cohort, rUTIs did not affect the graft function or survival. The etiology of rUTIs remains poorly understood, and there is a continuous need to study how rUTIs can be reduced and treated optimally. PATIENT SUMMARY: In this study, we looked at the risk factors for recurrent urinary tract infections in patients after kidney transplantation. We conclude that 21.5% of patients experience recurrent urinary tract infections 5 years after kidney transplantation. Multiple risk factors were found and should be taken into consideration by clinicians.