Thymopoietin pentapeptide treatment of primary immunodeficiencies

26 patients with primary immunodeficiencies (3 infants with severe combined immunodeficiency [SCID] 3 with DiGeorge syndrome, 6 with T-cell defect or SCID with B cells, 4 with common variable hypogammaglobulinaemia and associated T-cell defect, 5 with ataxia-telangiectasia, and 5 with hyper-IgE syndrome) were treated with thymopoietin pentapeptide (TP-5) at a dose of 0 . 5 mg/kg daily for 2 weeks and then 3 times a week at 0 . 5 mg/kg for 10 weeks, 3 patients with DiGeorge syndrome and 3 with primary T-cell defect demonstrated pronounced clinical and immunological improvement during treatment. None of the patients with SCID and 3 of 6 patients with SCID with B cells or primary T-cell defect showed any clinical or immunological changes during therapy. In 5 patients with ataxia-telangiectasia clinical manifestations and immunological tests were unchanged by TP-5. Abnormality of T cells in cases of hyper-IgE syndrome was not corrected by TP-5 treatment.