Prophylaxis of Recurrent Urinary Tract Infection After Renal Transplantation by Cranberry Juice and L-Methionine

Abstract Background Recurrent urinary tract infections (UTIs) increase mortality and reduce graft survival after renal transplantation. Strategies to prevent recurrent UTIs include L-methionine, cranberry juice, and antibiotics. Data on the efficacy of cranberry and L-methionine, however, are controversial in the general population; there are few data in renal transplant recipients. Methods We performed a retrospective analysis of 82 transplant recipients with recurrent UTIs, who underwent prophylaxis with cranberry juice (2 × 50 mL/d, n = 39, 47.6%), or L-methionine (3 × 500 mg/d, n = 25, 30.5%), or both modalities ( n = 18, 21.9%). Thirty patients without prophylaxis served as controls. We analyzed symptoms, pyuria/nitrituria, and incidence of UTI events during 1 year before versus after initiation of prophylaxis. Results Prophylaxis highly significantly decreased the annual UTI incidence by 58.3% ( P < .001) in the study population with no change in the control group ( P = .85); in addition, 53.7% of symptomatic patients reported relief of symptoms and pyuria/nitrituria disappeared in 42.4% of the dipstick-positive patients ( P < .001 each). Cranberry reduced the annual number of UTI episodes by 63.9% from 3.6 ± 1.4 to 1.3 ± 1.3/year ( P < .001) and L-methionine by 48.7% from 3.9 ± 1.8 to 2.0 ± 1.3/year ( P < .001). Conclusion Cranberry juice and L-methionine successfully reduced the incidence of UTI after renal transplantation.