Bone marrow transplantation and thymopoietin pentapeptide treatment in two infants with immunodeficiency with predominant T-cell defects.

Two infants with immunodeficiency with predominant T-cell defects received transplants of HLA-identical bone marrow cells along with thymopoietin pentapeptide (TP-5) treatment and no prior immunosuppressive therapy. Both patients achieved durable engraftment with early reconstitution of cell-mediated immunity. The study of cell surface antigens with monoclonal antibodies (MoAb) revealed that the early appearance of T-cell subsets defined by OKT4 and OKT8 MoAb occurred. Neither of the patients showed any signs or symptoms of graft versus host disease over a 1-year period. This experience suggests that patients with T-cell deficiency who do not benefit from thymic hormones alone can be successfully treated by bone marrow transplantation. The association of TP-5 with bone marrow transplantation seems to induce an early and stable reconstitution and to protect against fatal post-transplant infection.