Full hematopoietic engraftment after allogeneic bone marrow transplantation without cytoreduction in a child with severe combined immunodeficiency

Bone marrow transplantation (BMT) for severe combined immunodeficiency (SCI D) with human leukocyte antigen (HLA)-identical sibling donors but no pretr ansplantation cytoreduction results in T-lymphocyte engraftment and correct ion of immune dysfunction but not in full hematopoietic engraftment. A case of a 17-month-old girl with adenosine deaminase (ADA) deficiency SCID in w hom full hematopoietic engraftment developed after BMT from her HLA-identic al sister is reported. No myeloablative or immunosuppressive therapy or gra ft-versus-host disease (GVHD) prophylaxis was given. Mild acute and chronic GVHD developed, her B- and T-cell functions became reconstituted, and she is well almost 11 years after BMT. After BMT, repeated studies demonstrated : (1) Loss of a recipient-specific chromosomal marker in peripheral blood l eukocytes (PBLs) and bone marrow, (2) conversion of recipient red brood cel l antigens to donor type, (3) conversion of recipient T-cell, B-cell, and g ranulocyte lineages to donor origin by DNA analysis, and (4) increased ADA activity and metabolic correction in red blood cells and PBLs. (C) 2001 by The American Society of Hematology.