In a baby with DiGeorge syndrome, giving thymosin‑alpha‑1 to her blood cells in the lab did not increase T‑cell numbers, but a bone‑marrow transplant from her brother did improve her immune system and raised a thymic hormone in her blood. This suggests thymosin‑alpha‑1 alone may not boost T‑cells in severe thymic deficiency, while a transplant can help.

A Hispanic infant girl with DiGeorge syndrome underwent successful bone marrow transplantation (BMT) at age 28 1/2 weeks. She had typical facies, a cardiac defect, hypoparathyroidism, severe T and B cell immunodeficiency, and low levels of facteur thymique serique (FTS). In vitro incubation of the peripheral blood lymphocytes with thymosin alpha 1 showed no increase in the number of T cells on two occasions. A fetal thymus for transplantation was not available, and further review of past experience with thymic cells or factors revealed inconsistent and incomplete responses. Because of the patient's worsening clinical and immunologic status, BMT was performed, with her histocompatible brother as donor. The patient has had a good clinical and immunologic response to BMT, with evidence of T cell engraftment, improved B cell function, and increased levels of serum FTS. This experience indicates that minimal thymic influence is necessary for successful BMT and that patients with DiGeorge syndrome with significant T cell deficiency may benefit from this treatment.