Post-Transplant UTI Risk Factors Identified
Female kidney recipients have a nearly 7-fold higher risk of UTI than their male counterparts.
The observational, cross-sectional study, by Alparslan Ersoy, MD, of Uludag University Medical School in Bursa, Turkey, and colleagues, included 213 patients who underwent renal transplantation. Of these, 106 were diagnosed with 171 episodes of UTI, with recurrent UTI in 39 cases (36.8%). First UTIs occurred at a mean of 13.7 months after transplantation. The UTI group had a significantly greater proportion of female recipients than the non-UTI group (60.4% vs. 21.5%).
The rate and duration of ureteral catheterization were significantly greater in the UTI than non-UTI group (48.1% vs. 28% and 66.1 vs. 55.9 days, respectively), as was the proportion of patients with comorbidities (43.4% vs. 27.1%).
In regression analysis, female gender, ureteral catheterization, and co-morbid diseases were independently associated with a significant 6.8, 2.8, and 2.3 times increased risk of UTI, respectively. The risk of recurrent UTIs was 4.2 times higher among diabetic than non-diabetic recipients. Among patients with recurrent UTI, 1 had 5 episodes, 4 had 4 episodes, 15 had 3 episodes, and 19 had 2 episodes.
The UTI and non-UTI groups were similar with respect to donor type, primary disease, diabetes mellitus, acute rejection, and surgical complications, according to the investigators.
In a separate study of 1,019 transplant recipients presented at the meeting, researchers in Kuwait identified age, female gender, thymoglobulin induction, pretransplant urologic problems, and hepatitis C as risk factors for recurrent UTI in renal transplant recipients. The investigators divided patients into 2 groups: patients who had recurrent UTI (group 1) and those who had no or non-recurrent UTI) (group 2). Group 1 was significantly younger than group 2 (34.9 vs. 42.8 years); they also had a significantly higher proportion of female patients. Recurrent UTI did not adversely impact graft or patient survival.
These new studies add to a growing body of literature on UTI risk factors after kidney transplantation. In a recently published study in Medicine (2015;94:e594), researchers demonstrated that vitamin D deficiency is an independent risk factor for post-transplant UTI. A study published in Transplantation Proceedings (2014;46:3455-3458) found that the only risk factor for UTI after renal transplantation was gender, with female recipients at higher risk than male recipients.
Also in Transplantation Proceedings (2014;46:1757-1759), investigators reported on a study that identified older age (independent of gender), biopsy-proven acute rejection episodes, and receipt of kidneys from deceased donors as UTI risk factors. For female recipients, an additional risk factor was the number of pretransplant pregnancies. Researchers reported in Transplantation (2013;96:732-738) that their study of 1,166 kidney transplant recipients showed that post-transplant UTI risk factors included female gender, prolonged use of Foley catheters, ureteral stents, age, and delayed graft function.