High incidence of urinary tract malignancy among patients with haematuria following kidney transplantation in Taiwan.

Haematuria is a common complication following kidney transplantation, but few studies describing post-transplant haematuria have been published. Herein, we investigated the incidence and etiologies of persistent hematuria with kidney transplant patients in Taiwan. The medical records of 189 kidney transplant recipients with functioning grafts were retrospectively reviewed. Any episode of haematuria during routine follow-up was recorded and evaluated. The patient characteristics, possible causes of haematuria and consequent managements were reviewed. Among the 189 patients, 44 patients (23.3%) experienced 45 episodes of persistent haematuria during routine monthly follow-up at our transplant clinic. Thirty-two episodes (71%) were microscopic haematuria and 13 (29%) were gross haematuria. The most prevalent etiology explained for the persistent haematuria in our series was urologic malignancy (19 patients, 42.2%), followed by urinary tract infections (24.5%) and unexplained reasons (17.8%). Furthermore, those patients with persistent haematuria caused by urologic malignancy were also associated with significantly longer duration following transplantation and worse graft function. Haematuria is frequently seen in kidney transplant recipients and the most prevalent cause in our series is urologic malignancy. Those patients were also associated with significantly poorer graft function; however, the mechanism is still unclear.