Thymus Transplantation

Abstract

Successful reconstitution of cell-mediated immunity was achieved in a four-week-old infant with sex-linked severe combined immunodeficiency by intraperitoneal transplantation of a 14-week gestational-age fetal thymus. Ten days after transplantation, a new HL-A antigen was detected in the infant that was present in the mother of the thymus donor. Two months after transplantation, the patient's total lymphocyte count was normal. At four months, three of the pre-transplant HL-A antigens were not detectable, and three antigens of the mother of the thymus donor were present. Nine months after transplantation, the patient's in vitro phytohemagglutinin response and pokeweed mitogen response were normal. Immunologic reconstitution in this patient was probably achieved by lymphocyte repopulation, as evidenced by the length of time required for normal cell-mediated immune responses to develop, and by the development of lymphocyte HL-A chimerism. (N Engl J Med 289:5–9, 1973)