In-utero transplantation of parental CD34 haematopoietic progenitor cells in a patient with X-linked severe combined immunodeficiency (SCIDXI)

Background. X-linked severe combined immunodeficiency (SCIDXI) is an inherited immune effect which leads to death in infancy from severe infections. The defect is caused by mutations of the IL-2RG gene that encodes for the common γ chain shared by several cytokine receptors. The disease is characterised by lack of T and NK cells with normal numbers of B cells. SCIDXI can be cured by bone marrow transplantation (BMT) or prevented by abortion after prenatal diagnosis. Methods. A male fetus was diagnosed as having SCIDXI by molecular, immunophenotypic, and functional analyses. The fetus was injected intraperitoneally under ultrasound guidance with CD34 haematopoietic progenitor cells purified from paternal bone marrow and T-cell depleted by E rosetting. Chimerism analysis was by HLA-DQα typing and γ-chain staining on cord blood. Findings. A healthy 3.6 kg boy was delivered by caesarean section at 38 weeks of gestation with no clinical or laboratory signs of graft-versus-host disease. Engraftment of donor-derived CD2 cells was found at birth. At 3.5 months of age the infant is well and his T-cell counts and function are normal. Interpretation. In-utero transplantation of haematopoietic progenitor cells allowed immune resonstitution of a fetus with SCIDXI and may be an alternative to elective abortion. Our report should encourage applications of this method to other inherited disorders curable by BMT.