Buchbinder D, Younes B, Sassoon A, Soni A, Hsieh L, Puthenveetil G, Stites J, Ness-Jorden T, Neudorf S, Nugent D. Inflammatory polyps following successful HLA-matched cord blood transplantation in a patient with X-linked lymphoproliferative syndrome. Abstract: Gastrointestinal complications following HSCT are numerous and include a variety of issues resulting in hepatic, biliary, pancreatic, and intestinal compromise. In the context of an underlying state of immune dysregulation, novel complications may arise including autoimmunity. To our knowledge, this is the first report of a patient with XLP who was successfully treated with HSCT using an HLA-matched unrelated cord blood unit that was complicated by the development of inflammatory polyps of the colon. Given the underlying diagnosis of XLP and its associated immune dysregulation, the challenge of understanding unique gastrointestinal manifestations of autoimmunity following HSCT is discussed.