Objective: Aristolochic acid nephropathy (AAN) is a progressive renal interstitial fibrosis disease that was initially reported among a Belgian cohort of about 50 patients after the intake of diet pills containing the Chinese herb Aristolochia fangchi. In addition to renal disease, foci of AAN show increased incidences of urothelial carcinomas (UC). Immunosuppression is associated with an increased risk for the development of different malignancies. Our aim was to examine the outcomes of UC among patients with AAN after transplantation in China, the cradle of this traditional medicine.
Patients and methods: We performed a retrospective evaluation of the charts and pathology reports of 1612 renal transplant recipients treated at our 2 institutions.
Results: From January 1998 to December 2006, we performed cadaveric kidney transplantations in 17 patients with AAN, all of whom were treated with cyclosporine plus azathioprine or mycophenolate mofetil plus prednisone. One-year graft survival was 100%. During the mean follow-up of 57 months (range, 21-108 months), 9 recipients (52.9%) developed UC, compared with a 0.46% prevalence of urinary tract tumors among other Chinese kidney transplant recipients. The age at which the diagnosis was made ranged from 39 to 66 years (mean, 53.6 +/- 6.8 years). Among the 9 patients with UC, 8 cases (88.9%) involved the upper urinary tract: bilateral, 3 cases, 37.5%; unilateral, 5 cases, 62.5%. In 1 patient only a bladder tumor was detected. Two patients showed the bladder, synchronous bilateral ureter, and pelvis to be involved. All patients with UC underwent surgical treatment, recovering uneventfully with functioning grafts after tumor excision, except 1 patient who underwent nephrectomy of the transplanted kidney. Six patients (75%) experienced recurrences during the follow-up period. Three patients died within a mean of 20 months (range, 1-42 months) after tumor excision.
Conclusions: The risk for UC is increased among patients with AAN after transplantation. Regular screening for early detection of malignancy is mandatory. Longer follow-up and results from other transplant centers are needed to further investigate the relationship between AAN and UC among renal transplant patients.