De novo IBD after solid organ transplant: case series and risk factor analysis.

Abstract

Background: Diarrhea is a frequent complication of solid organ transplant (SOT) with significant morbidity. Potential causes include infections and medications, but there is increasing recognition of de novo inflammatory bowel disease (IBD) as a cause in this population. The aim of this study was to evaluate the incidence of de novo IBD in SOT recipients and identify any potential risk factors for its development. Methods: We conducted a retrospective, single center study of all patients receiving a solid organ transplant between 1988 and 2007. A diagnosis of de novo IBD was made based on clinical symptoms, exclusion of all other causes, and endoscopic and histologic criteria. Risk factor analysis was performed using a case-control design for liver transplant recipients. Results: During this time period 23 cases of de novo IBD were identified among 6270 transplant recipients: liver (16), kidney (5), lung (1) and pancreas (1). Of the 16 liver transplants, 8 were performed for PSC or AIH. De novo IBD type was UC in 12, Crohn’s disease in 9 and indeterminate in 2.The mean lag time between transplant and IBD diagnosis was 63.7 (10.4-240.5) months. The annual incidence for this cohort was 18.5 per 100,000. Among liver recipients, the annual incidence was much higher at 100 per 100,000 vs. 5.8 per 100,000 in the non-liver organ recipients. Neither CMV mismatch OR 1.55 (0.43-5.58), acute CMV infection OR 0.87 (0.25-3.07) nor tacrolimus exposure OR 5.26(0.55-50.022) could be confirmed as modifiable risk factors for developing IBD. Novel risk factors of personal or family history of autoimmunity, lymphopenia, and rejection episodes were not statistically significant. Conclusion: De novo IBD occurs in liver transplant recipients at a rate 5x higher than the general population and over 17x higher than other SOT recipients. Previously identified risk factors could not be confirmed. Since patients diagnosed with de novo IBD require additional medications beyond their transplant immunosuppression for treatment, recognition of this entity has important clinical implications.