Acute Graft Pyelonephritis During the First Year After Renal Transplantation

IntroductionUrinary tract infections are the most common infections in renal transplant recipients. Acute graft pyelonephritis (AGPN) is considered a potential risk factor for poorer graft outcomes; however, its clinical impact still remains controversial.MethodsThis study analyzed urine cultures performed within the first 12 months after renal transplantation with reference to clinical data of patients who received a renal transplant at Gdańsk Transplantation Centre between January 2007 and December 2009. Renal function assessed by creatinine concentration and estimated glomerular filtration rate was recorded 24 months after renal transplantation.ResultsThis study examined urine cultures and clinical data from 209 renal transplant recipients, including 59.3% men, with a mean age of 46 ± 14 years. We observed 70 AGPN episodes defined as the presence of significant bacteriuria, fever >38°, and/or graft pain and/or acute graft function impairment, including 13 cases of bacteremia, in 46 patients. This accounted for 22% of all diagnosed urinary tract infections. Over 80% of all AGPN episodes were diagnosed beginning from the second month posttransplantation, and the most frequently isolated uropathogen was Escherichia coli (65.7%, n = 46). Female sex, vesicoureteral reflux, or strictures at the ureterovesical junction and a history of cytomegalovirus infection emerged as independent predictors of AGPN. The evolution of renal graft function measured by serum creatinine concentration and MDRG eGFR rate did not differ significantly between patients with and without AGPN.ConclusionsAGPN may be a marker of an underlying impairment of urine flow, eg, due to vesicoureteral reflux or strictures at the ureterovesical junction, whereas it does not affect graft function in renal transplant recipients.