Immunologic Reconstitution in Severe Combined Immunodeficiency without Bone-Marrow Chromosomal Chimerism

Abstract

An 11-month-old male infant with severe combined immunodeficiency was immunologically reconstituted by bone-marrow transplantation from a female sibling whose cells were HL-A compatible on mixed leukocyte culture. The patient's lymphocytes demonstrated multiple extraneous HL-A antigens (up to 10 at one time), some of which were not present in the parents or the four siblings; this typing anomaly delayed bone-marrow donor selection. These additional antigens were nonstimulatory in mixed leukocyte culture, and since they were found in two similar patients, may represent an anomaly peculiar to combined immunodeficiency. After leukocyte transfer factor was given without benefit on two occasions, bone-marrow transplantation was performed. After a severe graft-versus-host reaction subsided, clinical improvement and chimerism ensued as evidenced by an XX (donor) karyotype of cultured peripheral blood lymphocytes and restoration of immunologic functions. Direct chromosome analysis of bone-marrow cells disclosed only XY cells, despite the presence of plasma cells synthesizing IgG-globulin of the donor's genetic type.