[Moderate aplastic anemia associated with Crohn's disease during antithymocyte globulin treatment]

A 53-year-old woman with moderate aplastic anemia (AA) was treated with antithymocyte globulin (ATG). However, on the 4th day of treatment, ATG was discontinued because of bloody vomiting and melena. The patient improved with conservative treatment but complained of abdominal pain when the prednisolone (PSL) dose was decreased. Crohn's disease was finally diagnosed on the basis of upper and lower gastrointestinal X-ray studies. The patient responded well to ATG with hematologic improvement, and maintained remission with low-dose PSL and nutritional support. Drug-induced AA may occur during treatment for Crohn's diseases. The association of AA and Crohn's disease is rare, and to our knowledge, has not yet been reported in the literature. We discussed the pathogenesis of Crohn's disease during immunotherapy for AA.