Published online Feb 24, 2017. doi: 10.5500/wjt.v7.i1.98
Peer-review started: November 29, 2016
First decision: December 15, 2016
Revised: December 21, 2016
Accepted: January 11, 2017
Article in press: January 13, 2017
Published online: February 24, 2017
Mycophenolate mofetil (MMF) is an important medication used for maintenance immunosuppression in solid organ transplants. A common gastrointestinal (GI) side effect of MMF is enterocolitis, which has been associated with multiple histological features. There is little data in the literature describing the histological effects of MMF in small intestinal transplant (SIT) recipients. We present a case of MMF toxicity in a SIT recipient, with histological changes in the donor ileum mimicking persistent acute cellular rejection (ACR). Concurrent biopsies of the patient’s native colon showed similar changes to those from the donor small bowel, suggesting a non-graft specific process, raising suspicion for MMF toxicity. The MMF was discontinued and complete resolution of these changes occurred over three weeks. MMF toxicity should therefore be considered as a differential diagnosis for ACR and graft-versus-host disease in SITs.
Core tip: Mycophenolate mofetil (MMF) is a commonly used medication for maintenance immunosuppression in small intestine transplant (SIT) recipients. Enterocolitis is a known side effect of MMF therapy, but there is little literature describing its histological manifestations in SIT recipients. Our case shows that MMF enterocolitis can mimic acute cellular rejection (ACR) and highlights the importance of attempting to biopsy the native gastrointestinal tract in SIT recipients if possible. If the native biopsy is abnormal, drug toxicity should be considered as a differential diagnosis as it may show overlapping features with ACR.