Reconstitution of cell-mediated immunity in severe combined immunodeficiency following fetal liver transplantation.

A male infant X-linked, adenosine deaminase-positive severe combined immunodeficiency underwent partial immunological reconstitution by fetal liver transplantation at twenty months of age. Reconstitution of T lymphocytes was observed from sixteen weeks after transplantation, in the increase of T lymphocytes, positive delayed-type skin reaction and in vitro responsiveness to mitogens and allogeneic cells, sequentially. Chimerism was defined by chromosomal analysis and HLA typing, in which one haplotype seemed to be shared between the donor and the host by chance. However, defective immunoglobulin production has not yet been corrected. The assay on T-B lymphocyte interaction in vitro suggested that the failure might be attributed to an intrinsic defect of B lymphocytes, which were cells of donor origin after transplantation. Three years following transplantation, the patient is free of severe infections, although he requires regular injections of gamma globulin.