Thymus Transplantation With Immunosuppression, #884

DiGeorge anomaly is a complex of cardiac defects, parathyroid deficiency, and thymus absence, resulting in profound T-cell deficiency. There is a spectrum of disease in DiGeorge anomaly with respect to all three defects. For complete DiGeorge anomaly subjects with severe T cell defect, the PI had shown that thymus transplantation is safe and efficacious without pretransplantation immunosuppression and with pretransplantation Thymoglobulin and cyclosporine.

Some DiGeorge patients have very poor T cell function and are at risk of death from infection or other immune problems; however, these patients have enough T cell function to reject grafts. This protocol was designed for these patients. Atypical phenotype and some typical phenotype DiGeorge subjects were included in this protocol.

Atypical complete DiGeorge anomaly patients have rash, lymphadenopathy, and oligoclonal T cell proliferations. The T cells have no markers of thymic function (they do not co-express CD45RA and CD62L; they do not contain T cell receptor rearrangement excision circles, TRECs).

Typical complete DiGeorge anomaly patients in this protocol are those whose PHA response >20 fold. Although these patients have very low T cell function, it may be enough to reject a transplant, so Thymoglobulin was used.