Vaccination Against Urinary Tract Infection After Renal Transplantation

Recurrent urinary tract infections (UTIs) increase mortality and reduce graft survival after renal transplantation. Because current prophylactic strategies such as methionine, cranberry juice, and antibiotics fail to sufficiently prevent recurrent infections in a substantial number of patients, there is a clinical need for alternative approaches. The present work describes first experiences with an immunization strategy against bacterial strains after kidney transplantation.

We performed a retrospective single-center analysis of an immunization approach against 10 strains of inactivated bacteria (StroVac). A total of 14 renal transplant recipients with 3 or more UTI episodes/year underwent immunization with 3 subcutaneous injections of inactivated bacteria (follow-up 12 months before to 12 months after immunization). These patients were compared to 14 renal transplant patients without immunization who were matched for number of UTIs and time after transplantation (24 months follow-up). We compared the UTI incidence and potential side effects, including development of de novo donor-specific antibodies (DSA).

The immunization significantly decreased the incidence of UTIs from 3.4 ± 1.3 to 0.9 ± 1.0 by 74.9%. The incidence did not change from year 1 to year 2 of the observation period in the control group. Immunization was tolerated well, without any clinical complaints. There were no de novo DSAs in the first year after immunization.

Immunization against inactivated bacterial strains substantially reduced the incidence of UTIs without eliciting any safety concerns in this small cohort of renal transplant recipients. This strategy may be a helpful expansion of our preventive measures in patients with recurrent UTIs.