Inflammatory bowel disease (IBD) that develops after solid organ transplantation has often reported after liver transplantation, but not in kidney transplantation.
We report two cases of IBD that developed or relapsed after living kidney transplantation at our hospital and Kindai University Hospital.
Case 1.
A 53-year-old man, diagnosed with ulcerative colitis at age 20 and underwent living kidney transplantation at age 36, with his mother as donor. His gastrointestinal symptoms were in remission, but 7 years after kidney transplantation, he developed fever and diarrhea and he was diagnosed with relapse of ulcerative colitis. The patient had intractable hematochezia. Despite reduction of immunosuppressive drugs, he did not improve. He was treated with steroid pulse therapy and once went into remission. The same process was repeated 3 times in 8 years. 16 years after kidney transplantation, he had a relapse again, so we initiated vedolizumab and maintained remission for 2 years.
Case 2
A 54-year-old woman who underwent living kidney transplantation at age 32, with his father as donor. 22 years after kidney transplantation, her renal function was stable, but she developed fever and diarrhea and was diagnosed with Crohn's disease by colonoscopy. She was treated with fasting, but her symptoms did not improve. Althought we initiated vedolizumab, diarrhea did not improve. Therefore, we initiated infliximab, and symptoms improved and maintain remission for 6 months.
Calcineurin inhibitors (CNIs) suppress IL-2 secretion from CD4⁺ T cells, which is involved in the differentiation and proliferation of regulatory T cells (Tregs) that exert suppressive effects on immune responses. The inhibition of IL-2 may disrupt the balance of mucosal immune regulatory mechanisms, potentially contributing to the onset of IBD. Regarding the treatment of IBD after kidney transplantation, there is no established standard therapy due to concerns about interactions between IBD medications an immunosuppressants. Generally, 5-ASA is the first-line therapy for IBD, with oral steroids considered for patients who do not respond sufficiently to 5-ASA. For steroid-dependent patients, treatment options include azathioprine, 6-mercaptopurine, TNF inhibitors, or vedolizumab.
The safety of infliximab for post-kidney transplant IBD patients has not been established, but in this case, remission was achieved without causing renal dysfunction.