Successful related umbilical cord blood transplantation for graft failure following T cell-depleted non-identical bone marrow transplantation in a child with major histocompatibility complex class II deficiency

Major histocompatibility complex (MHC) class II deficiency is a rare form o f primary combined immunodeficiency that can only be corrected by stem cell transplantation. We report a 4 1/2-year-old girl with MHC class Il deficie ncy who underwent a related CBT due to graft failure following T cell-deple ted non-identical BRIT. The patient is alive and well 2 years after the sec ond transplant. A sustained hematopoietic engraftment and a progressive imm une recovery have been detected. We conclude that cord blood may be an effe ctive source of hematopoietic stem cells for patients with immunodeficiency disorders including diseases with a high rate of graft failure.