Third salvage haematopoietic stem cell transplantation in a child with very early-onset IBD due to interleukin-10 receptor deficiency.

A girl with very early-onset inflammatory bowel disease due to a loss-of-function IL10RA mutation (c.611G>A p.Trp204*) presented in infancy with severe Crohn's disease-like colitis requiring colectomy. Two matched-sibling allogeneic haematopoietic stem cell transplantations using treosulfan-based conditioning engrafted transiently but ultimately failed with autologous recovery and immune cytopenias. A third transplant from the same donor with busulfan/fludarabine/melphalan plus serotherapy and peripheral blood stem cells achieved durable engraftment. Acute skin and gut graft-versus-host disease responded to corticosteroids and etanercept. On long-term follow-up, the patient remained off immunosuppression with stable donor chimerism, normal immunoglobulins, nutritional catch-up (weight), preserved puberty and regular menses though short stature persisted.