PRACTICAL GASTROENTEROLOGY • NOVEMBER 2006 70 Flare of Crohn’s Disease in a Patient Receiving Chronic Tacrolimus Therapy: A Case Report and Literature Review INTRODUCTION T he current treatments of choice for active CD include 5-ASA compounds, immunomodulators, corticosteroids, and antibiotics. Steroid therapy, however, can be ineffective at times and resistance to this treatment has been documented (1,2). Conven- tional immunosuppressive therapies, such as azathio- prine (AZA) and 6-mercaptopurine (6MP) have a slow onset of action and therefore, are initially used in com- bination with other treatment modalities (1,3). Treat- ment with anti-tumor necrosis factor (TNF-α) is costly and requires intravenous infusions and is ineffective in a subset of patients. Tacrolimus and cyclosporine A (CsA) are drugs currently used to prevent allograft rejection following organ transplantation. Small uncontrolled studies of these agents have shown favor- able results in the treatment of CD and ulcerative col- itis (UC) (1–5). In addition, a recent placebo-con- trolled trial of tacrolimus in fistulizing CD demon- strated fistula response but little fistula closure (6). We report here a case of new-onset CD while the patient was receiving tacrolimus for prevention of renal allo- graft rejection. A CASE TO REMEMBER Robin B. Forman, D.O., Petros Benias, M.D., Tamer N. Sargios, M.D., Brett B. Bernstein, M.D. and Henry C. Bodenheimer, Jr., M.D., all from the Division of Digestive Diseases, Beth Israel Medical Center, Albert Einstein College of Medicine, New York, NY. by Robin B. Forman, Petros Benias, Tamer N. Sargios, Brett B. Bernstein and Henry C. Bodenheimer, Jr. We report a case of Crohn’s disease (CD) of new onset in a patient being treated with tacrolimus for the prevention of renal allograft rejection. Tacrolimus is a calcineurin inhibitor used as a first-line immunosuppressive drug in organ transplant recipients to prevent allograft rejection. Recent reports also suggest a role for the drug in the treatment of CD. This case reports the onset of CD in a patient already on a potent immunosuppressive regimen. Such cases of new onset CD and CD refractory to immunosuppressive therapy support the idea that the pathogenicity of this disease is multifactorial involving multiple arms of the immune response.