Clinical Case Scenario
A 56-year-old female has a recent history of undergoing a heart transplant. She is admitted to the intensive care unit with new-onset oliguria. Her baseline serum creatinine prior to her heart transplant was 0.8 mg/dL. She had a stable post-transplant serum creatinine at 1.2 mg/dL on her maintenance immunosuppression regimen of cyclosporine and mycophenolate mofetil. However, over the past 48 hours, her serum creatinine has increased to 2.8 mg/dL, and her urine output has decreased to less than 20 mL/hour. Her BUN/serum creatinine ratio is noted to be 10. She is hemodynamically stable, and a renal ultrasound shows no evidence of obstruction. Her most recent cyclosporine trough level was 200 ng/mL.
Which of the following is the MOST likely cause of this patient's acute kidney injury?
