How Early Postoperative Urinary Tract Infections Affect Renal Graft Function at 1-Year Follow-up

Background: Urinary tract infection (UTI) occurs in 21% of kidney recipients within the first 3 months after transplantation (KTx). It is associated with impaired graft function. Ureteral stent placement increases the occurrence of UTIs. The aim of this study was to assess the correlation between double-J placement, UTI incidence, and graft function.

Material And Methods: We conducted an observational study in 753 patients transplanted between 2010 and 2017 in compliance with the Helsinki Congress and the Istanbul Declaration. Recipients with preserved graft function at the 1-year follow-up were included. Medical records were searched for intraoperative double-J placement, UTI incidence, and estimated glomerular filtration rate (eGFR) on the 30th and 360th days post-transplant. Pretransplant hypothetical estimated GFR (heGFR) of each donor was calculated from donors' age and physiological age-dependent loss of functional nephrons. Spearman's correlation and linear regression analyses were applied. P < .05 was considered significant.

Results: UTIs occurred in 239 (31.8%) patients. On the 30th day after KTx, eGFR was significantly lower in the UTI group (median, 39.5 vs 43.2; P < .01). A similar pattern was seen 1 year after KTx (47.5 vs 54.2; P < .01). Urinary stents were placed in 213 (28.3%) patients. UTIs occurred in 92 (43.2%) of them and in 147 (27.2%) of nonstented patients (odds ratio: 2; 95% confidence interval [CI], 1.5-2.8; P < .01). Median donor heGFR was 105.8 mL/min/1.73 m, whereas median donor Modification of Diet in Renal Disease (MDRD) GFR was 64.2 mL/min/1.73 m. A moderate correlation between age-adjusted heGFR and 1-year transplant function (r = .47) was noted.

Conclusions: UTIs in the early post-transplant period decreased 1-year eGFR by 4 to 5 mL/min/1.73 m. UTIs occurred twice as often when a urinary stent was placed.