Thalidomide as treatment of crohn‐like disease occurred after allogeneic hematopoietic stem cell transplantation in a pediatric patient

BACKGROUND Autoimmune diseases may occur after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and inflammatory bowel disease (IBD or Crohn disease) is rarely described. We describe a child who developed CD after allo-HSCT, successfully treated with thalidomide. CASE REPORT A child affected by mucopolysaccharidosis type I received two allogeneic HSCTs for rejection after the first one. After cutaneous and intestinal chronic GvHD and 6 months after HSCT, the patients developed a trilinear autoimmune cytopenia successfully treated with rituximab and sirolimus. Due to persisting intestinal symptoms, colonoscopies were performed and histological findings demonstrated a picture of CD. Based on this observation and according to the recommendations for the treatment of CD, thalidomide was started. A complete stable clinical response was obtained 8 weeks after start of thalidomide. Colonoscopy performed 4.8 years later demonstrated a complete endoscopic and histological remission of CD. DISCUSSION In this case, the diagnosis of CD after HSCT was based on histological findings. Indeed, repeated colonscopies were necessary for diagnosis, since both clinical and endoscopic features are often common to chronic GvHD and CD. Thalidomide was started at the dose of 1.7 mg/Kg/day, and it was well tolerated. Mild peripheral neurotoxicity occurred 5 years later but disappeared completely with the dose reduction. Currently, the patient is in complete remission from CD, despite the discontinuation of all the immunosuppressive therapies. CONCLUSIONS Thalidomide could represent a therapeutic option to treat CD as autoimmune disease after allogeneic HSCT.