Do urinary tract infections trigger chronic kidney transplant rejection in man?

Urinary tract infections are frequent after kidney transplantation but little is known about the impact on long-term survival. As chronic rejection is the major cause of graft loss in the long term, we retrospectively analyzed the role of urinary tract infections in this process.

We included in the study all adult patients who received kidney transplants at our unit between 1972 and 1991, which ensured followup of at least 5 years, and we focused on the relationship between urinary tract infections and the incidence of chronic rejection episodes. To analyze the influence of urinary tract infections on chronic rejection patients were separated into those in whom biopsy proved chronic rejection developed within the first 5 years after transplantation (chronic rejection group 225) and those without apparent signs of chronic rejection during that period (control group 351). The correlation between urinary tract infections per year and the incidence of chronic rejection was analyzed.

Patients with chronic rejection had more urinary tract infections per year than controls. In the first year after transplantation both groups had the highest incidence of urinary tract infections but thereafter the rate of urinary tract infections per year declined. However, the incidence consistently remained higher in the chronic rejection group. This difference reached significance by year 3 after transplantation. Furthermore, a high rate of urinary tract infections correlated with an early onset of chronic rejection.

Urinary tract infections are an important risk factor for the onset of chronic rejection, and early and intense treatment is critical.