Compatible bone marrow transplantation and immunologic reconstitution of combined immunodeficiency disease.

To date, bone marrow transplantation affords the only successful means of achieving full immunologic reconstitution of patients with severe combined immunodeficiency disease (SCID). We have achieved immunologic reconstitution in 6 of 7 SCID patients using marrow transplants from compatible sib donors. One child died of Pneumocystis carinii pneumonia following early immunologic reconstitution. A second child died of sepsis without evidence of engraftment, despite 3 marrow grafts, and a third died unexpectedly from massive aspiration pneumonia following complete immunologic reconstititon. Thus, in 4 of 7 children with SCID full and long-lasting immunologic reconstitution has been achieved by transplantation of marrow from matched sib donors. From these initial efforts, much has been learned, and it is clear that several factors, some of which remain poorly understood, may influence the outcome of marrow grafting. However, despite the difficulties encountered, bone marrow transplantation continues to hold real promise for correction of this otherwise fatal disease.