Matched Unrelated Donor Hematopoietic Stem Cell Transplant as Successful Curative Therapy for IL10RB Mutation‐Associated Very Early Onset IBD.

Background: Inflammatory bowel diseases are complex chronic disorders with a relapsing–remitting course that affect the gut due to dysregulated immune response. The incidence of these disorders is increasing globally along with an increase in the incidence in pediatric population. Very early onset inflammatory bowel diseases are seen in children with age less than 6 years, where monogenic causes predominate. With the advent of next‐generation sequencing methods, these disorders are being diagnosed more. Interleukin‐10 receptor mutation‐associated inflammatory bowel diseases is one such monogenic disorder where immunosuppression shows poor response. Methods: We report the case of an 8‐month‐old child of Indian origin who presented with severe enterocolitis and rectovaginal fistulas. She was evaluated on lines of a very early onset inflammatory bowel disease. She was found to have a mutation in the interleukin‐10 receptor causing severe enterocolitis. She underwent a diversion colostomy. She was admitted at 25 months of age for the hematopoietic‐stem‐cell‐transplant (HSCT). The conditioning regimen used consisted of busulfan, fludarabine, and anti‐thymocyte‐globulin (ATG). The child received a 10/10 human leukocyte antigen (HLA) matched from a matched‐unrelated adult female donor with bone marrow stem cell product at a dose of 5.6 million CD34+ cells per kg. Results: She was treated successfully by a matched unrelated donor HSCT. At present, she is 2 years and 4 months posttransplant and is cured. Conclusions: Early recognition and prompt genetic testing can help in diagnosing and establishing the cause of a very early onset inflammatory bowel disease. Very early onset inflammatory bowel disease caused due to interleukin‐10 receptor mutations can be cured by HSCT. [ABSTRACT FROM AUTHOR]