Abstract 17: IL10R Deficiency and Hemopoietic Cell Transplantation (HCT): Outcome of 2 Patients Treated in a Single Center with CBU HCT

Abstract Introduction IL10R deficiency is a congenital cause of very-early onset inflammatory bowel disease (VEO-IBD). Therapeutic strategie immunosuppressive agents, surgery and hemopoietic cell transplantation (HCT). Objectives We report on two patients (one male and one female) affected with IL10R deficiency successfully treated with HCT. Methods We report on two patients (one male and one female) affected with IL10R deficiency successfully treated with HCT. Results The first patient is a Moroccan male that presented with failure to thrive and diarrhea few weeks after birth. Histologic assessment showed signs of diffuse ulcerative colitis and CD8+ lymphocytes infiltration. Genetic studies revealed a homozygous variant c.[T569C];[T569C] in the IL10RA gene, classified as pathogenetic by functional studies. The patient was first managed with immunosuppressive agents with partial response. Therefore, at the age of 2 years he was transplanted with an Unrelated Cord Blood Unit (CBU) after myeloablative conditioning with Busulfan and Fludarabine and Graft-versus host (GVHD) prophylaxis with Anti-Thymocyte globulin (ATG), Cylcosporine (CSA) and Mofetil Mycophenolate (MMF). The patient is now completely asymptomatic with no sign of GVHD at 42 months after HCT and presents a full donor chimerism and complete immune reconstitution. The second patient is an Italian female that presented at few months of age with failure to thrive, recurrent infections and severe enterocolitis. Histologic studies showed features of severe ulcerative colitis associated with immunodeficiency. Genetic studies revealed a compound heterozygosity in IL10RA c.[C1080A];[G1082A]. Because of failure of other pharmacological therapies, the patient was successfully transplanted with an Unrelated CBU at two years of age after myeloablative conditioning with Treosulfan, Fludarabine and Thiotepa and GVHD prophylaxis with ATG, CSA and MMF. She is currently at 5 years post-HCT, completely asymptomatic without signs of GVHD. She shows a full donor chimerism and complete immune reconstitution. Discussion VEO-IBD may present an extremely severe clinical course with high risk of morbidity and complications. HCT can offer a possibility of cure for these patients with CBU being a reliable source for stem cells, given its unique properties. Moreover patients with VEO-IBD usually receive HCT very early and with low weight, thus increasing the feasibility and possibility of success of this procedure.