Acute graft pyelonephritis following renal transplantation

Urinary tract infection is the most common form of bacterial infection encountered in a renal transplant recipient. Studies explaining the long-term consequences of acute graft pyelonephritis (AGPN) are few.

A total of 1022 consecutive renal allograft recipients were studied retrospectively over a period of 10 years for evidence of AGPN. These patients were classified into two groups according to the presence or absence of at least one AGPN episode. Only culture-proven infections were included in the study.

Of the 1022 renal transplant recipients, 169 patients (16.5%) developed AGPN. In the multivariate analysis with stepwise logistic regression, significant associations were observed between AGPN and placement of ureteric stent (odds ratio [OR]=4.6), urological malformations of native kidney (OR=2.1), cytomegalovirus (CMV) disease (OR=2.0), mycophenolate mofetil (MMF)-based regimen (OR=1.9), and acute rejection episodes (OR=1.5). However, age>40 years, female gender, induction therapy, anti-CD3 treatment, and hyperglycemia did not show such an association. In comparison with the non-AGPN group, these patients had a lower graft and patient survival (though it did not attain statistical significance). In the multivariate analysis using the Cox model for the entire study population, AGPN did not independently contribute to poor graft or patient survival.

AGPN in the renal transplant setting is an ominous event, as these patients are also more prone to develop bacteremia, acute rejection, and CMV disease, which could then lead to poor graft and patient survival. Its association with MMF needs further clarification.