Emphysematous Pyelonephritis as a Presentation of Delayed Venous Allograft Thrombosis

Introduction: While transplant allograft thrombosis commonly manifests during the immediate post-transplant period, a delayed onset may occur and lead to allograft loss. We present a case of a kidney transplant (KT) recipient who presented with anuric acute kidney injury and emphysematous pyelonephritis. Case Description: A 45-year-old woman with ESKD who underwent a deceased donor kidney transplant 1 month prior presented with nausea and vomiting for two days. She had been doing well post-KT with a serum creatinine of 1.3 mg/dL 1 week prior. She had anuric AKI over 24 hours prior to admission with a creatinine of 5 mg/dL. An abdomen and pelvic CT scan showed severe emphysematous pyelonephritis of the transplant kidney and a 7 cm air-fluid collection in the abdomen, contiguous with the transplant kidney. Within hours after admission, she progressed to septic shock. Allograft function remained unimproved despite initial management of antibiotics and fluids. Therefore, transplant allograft nephrectomy was performed to eliminate the infection source. Pathology showed liquefactive necrosis and emphysematous changes of the transplant kidney, and thrombosis of the transplant renal vein. Hypercoagulable work-up is pending and she reinitiated hemodialysis and is referred for pretransplant evaluation for the second KT. Discussion: Vascular complication is a major concern during the acute post-transplant period. But a late onset of the venous allograft thrombosis may occur and lead to allograft loss complicated by severe life-threatening infections like emphysematous pyelonephritis. Early diagnosis by imaging and transplant allograft nephrectomy are warranted to reverse immunosuppressed status and avoid mortality.