Thymus Transplantation in DiGeorge Syndrome #668

Cultured thymus tissue for implantation (CTTI) (previously described as transplantation) is done using allogeneic cultured postnatal tissue from unrelated thymus donors. Thymus tissue, the thymus donor, \& thymus donor's birth mother were screened for safety. Approximately 2-3 weeks post-harvest thymus slices were implanted into the recipient's quadriceps. Dose was number of grams of cultured thymus tissue divided by the recipient's weight in kilograms. Minimum dose was 4 g/m2. Maximum dose 18g/m2. At time of CTTI, a skin biopsy was obtained to look for preexisting T cells. 2-3 months post-CTTI allograft biopsy to evaluate for thymopoiesis \& graft rejection. At time of biopsy, skin biopsy done to look for T cell clonal populations. Post-CTTI, subjects followed by routine research immune evaluations, using blood samples for approximately 2 years.