Graft Contrast-Induced Nephropathy Caused by Prerenal Transplant Computed Tomography: A Case Report.

Background: We report a case of posttransplant contrast-induced nephropathy (CIN) that occurred after performing computed tomography (CT) scanning for pretransplant cardiac and vascular evaluation.

Case Presentation: The patient had an 8-year history of hemodialysis and was admitted to the hospital for a kidney transplant from a deceased donor. Cardiac CT imaging and 3-dimensional low-extremity CT angiography were performed to confirm the patient's cardiac and iliac artery function. After successful transplantation surgery, the patient had a urine output of 250 mL and a reduced creatinine level from 8.8 to 2.3 mg/dL on postoperative day 4. However, urine output suddenly decreased to 30 mL and the creatinine level suddenly increased to 7.6 md/dL without any symptoms such as fever or graft tenderness. The patient tested negative for panel-reactive antibodies and donor-specific antibodies, and he was discharged 1 week later with an improvement in symptoms. Results of a graft biopsy indicated CIN, and the contrast-enhanced kidney was observed on noncontrast CT imaging that was performed immediately after transplantation to rule out vascular problems as well as other complications.

Conclusions: There may be residual contrast present from pretransplant CT imaging, which could affect the functional kidney grafts after transplantation and can lead to CIN. This scenario could potentially lead to loss of graft function, suggesting that caution should be observed when ordering CT imaging in this patient population.