Transplantation Immunology Practice Test

A 35-year-old man has fever and rising creatinine 2 weeks after kidney transplant while on tacrolimus, mycophenolate, and prednisone; biopsy shows interstitial lymphocytes with tubulitis. Which of the following is the best initial treatment for this patient?

A 60-year-old woman has slowly worsening cholestatic labs 5 years after liver transplant; biopsy shows fibrosis and narrowed bile ducts; she takes tacrolimus. Which of the following is the most likely cause of the observed symptoms?