title: Endoscopic and histological features of mycophenolate mofetil colitis in patients after solid organ transplantation.
abstract: BACKGROUND
  Mycophenolate mofetil (MMF) is an immunosuppressive agent commonly used after organ transplantation. Gastrointestinal side effects occur in approximately 45% of patients. The spectrum of histologic features associated with MMF colitis has been well described, but data on the endoscopic features is lacking. The aim of the study was to describe the endoscopic features of MMF colitis in solid organ transplant recipients (SOTRs) as well as the frequency of histologic features and identify associated risk factors.
  
  
  METHODS
  A retrospective review of all SOTRs taking MMF and who underwent colonoscopy between 2000 and 2010 was performed. 36 cases of MMF colitis were identified and 361 patients served as controls. Descriptive statistics and data analysis looking for associated risk factors were performed.
  
  
  RESULTS
  Among SOTRs taking MMF who underwent colonoscopy, MMF colitis was diagnosed in 9%. Endoscopic findings ranged from erythema (33%) to erosions/ulcers (19%). 47% of patients had a normal colonoscopy and everyone had rectal sparing. Histological findings included acute colitis-like findings (50%), inflammatory bowel disease-like characteristics (36%), ischemia-like findings (5.6%), and graft-versus-host disease-like features (8.3%). Diarrhea occurred in 83%. Kidney transplantation was associated with a higher risk of MMF colitis (OR 5.8 [2.86-11.86], P<0.0001) whereas liver transplantation was associated with a lower risk (OR 0.06 [0.03-0.16], P<0.0001).
  
  
  CONCLUSIONS
  MMF colitis is fairly prevalent in SOTRs taking MMF who undergo colonoscopy. Diarrhea is the most common reason for colonoscopy referral (83%) and up to 47% of patients have normal colonoscopy, suggesting the need for routine biopsies to help confirm the diagnosis.
authors.affiliation: Division of Gastroenterology, Department of Medicine, University of Miami Miller School of Medicine (Fernando H. Calmet, Andres J. Yarur), USA.
authors.forename: Fernando H
authors.initials: FH
authors.lastname: Calmet
authors.affiliation: Division of Gastroenterology, Department of Medicine, University of Miami Miller School of Medicine (Fernando H. Calmet, Andres J. Yarur), USA.
authors.forename: Andres J
authors.initials: AJ
authors.lastname: Yarur
authors.affiliation: Jackson Memorial Hospital, Miami (Geetha Pukazhendhil), USA.
authors.forename: Geetha
authors.initials: G
authors.lastname: Pukazhendhi
authors.affiliation: Division of Liver Diseases, Mount Sinai School of Medicine, New York (Jawad Ahmad), USA.
authors.forename: Jawad
authors.initials: J
authors.lastname: Ahmad
authors.affiliation: Division of Hepatology, Department of Medicine, University of Miami Miller School of Medicine, Miami (Kalyan R. Bhamidimarri), USA.
authors.forename: Kalyan R
authors.initials: KR
authors.lastname: Bhamidimarri
keywords: Colitis; colonoscopy; mycophenolate mofetil; mycophenolic acid; transplant recipients