Complete DiGeorge anomaly is a congenital disorder characterized by athymia. Without successful treatment, children remain immunodeficient and usually die by age 2 years. In infants with complete DiGeorge anomaly and no T cells, cultured thymus tissue implantation (CTTI) without immunosuppression resulted in diverse T cell development and good T cell function. Some infants with no thymus have some T cells that presumably developed extrathymically; these T cells can reject a thymus graft.~The purpose of this study is to tailor immunosuppression use for complete DiGeorge anomaly subjects who have some T cells and different T cell function levels. This protocol includes tailored immunosuppression regimens to allow subjects with different T cell function levels to be suppressed adequately.~Patients with complete DiGeorge often have hypoparathyroidism, a life threatening condition. Successful CTTI does not result in improvement of the hypoparathyroidism. The patients must go to the clinic for frequent calcium levels and to the hospital for calcium infusions. These infants are at risk for seizures from low calcium. This study had a parental parathyroid transplant arm for subjects with hypoparathyroidism who require calcium replacement.~Whether or not a subject was enrolled in the parathyroid arm, the immunosuppression regimen the subject received was dependent on the immune findings as stated in the clinical protocol.
The study purpose is to determine if cultured thymus tissue implantation (CTTI) (previously described as transplantation) with tailored immunosuppression based on the recipient's pre-implantation T cell population is a safe and effective treatment for complete DiGeorge anomaly. This study will also evaluate whether cultured thymus tissue implantation and parathyroid transplantation with immunosuppression is a safe and effective treatment for complete DiGeorge anomaly and hypoparathyroidism.