Early Post-Transplant Urinary Tract Infections; Impact on Graft and Patient Survival

Abstract

Introduction: Sepsis is the commonest cause of morbidity and mortality following solid organ transplantation. Urinary Tract Infections (UTI) including graft pyelonephritis is the commonest cause for sepsis related graft and patient loss following renal transplantation. Significant pyuria (pus cells >10 per high power field in a standard urinanalysis) is a common finding in End Stage Renal Disease (ESRD). The causative factors include low urine volumes, bladder stasis, underlying renal parenchymal disease, chronic haemodialysis, and latent or overt UTI. Its presence often confounds the decision and timing of renal transplantation. In this study we looked at the possible association of pre-operative pyuria with the incidence of post-transplant UTI, other identifiable risk factors for post-transplant UTI and their overall impact on graft and patient survival. Methodology: Three hundred and four (304) consecutive kidney transplants performed by the Colombo University Transplant Unit, Sri Lanka between January 2007 and March 2011 were prospectively analysed. All were living donor transplants and the mean follow up was 12(2-36) months. All those with significant pyuria were investigated extensively prior to transplantation to exclude a treatable cause (UTI, stones, tuberculosis etc.). If a treatable cause was identified, it was treated completely before proceeding to transplantation. All transplant ureters were routinely stented and routine standardized antibiotic prophylaxis was given perioperatively. Results: A total of 62 (62/304, 20%) early UTI were encountered in this cohort which included 15(5%) cases of graft pyelonephritis. In a multivariate analysis, diabetes mellitus in the recipient (p=0.9), female gender (p=0.7), acute rejection in the first month (p=0.3) and pre-operative pyuria (p=0.6) were not significantly associated with early UTI. 49/62 (79%) of the UTIs were successfully treated with complete resolution while 6 (10%) were associated with Primary Graft Failure (PGF) and 5 (8%) with sepsis related deaths. One with PGF also died during follow up while 1 was re-transplanted after complete resolution of the UTI. Four patients with PGF remain on haemodialysis awaiting re-transplantation. Conclusion: The incidence of post-transplant UTI is high in our experience. Likewise, the incidence of significant pyuria in the local population awaiting renal transplantation in this resource limited setting has also been shown to be high. However, this study showed that once a treatable cause was excluded or treated, pre-operative pyuria did not have any significant correlation with post-transplant UTI. The quest for minimizing UTI and thereby the related graft and patient loss continues.