A case of Di George syndrome treated with thymopoietin pentapeptide (TP-5) demonstrating an adherent suppressor cell of lymphocyte function.

A child with the classical features of Di George syndrome is described. The patient was treated with TP-5 and the number of peripheral blood E-rosette forming cells rose from 11% to 69% but then fell to 33% prior to death. There was poor correlation between the number of T-cells estimated by rosetting with sheep red blood cells and that measured by cytotoxicity to the OKT3 antiserum and complement. Although the total T-cell numbers were reduced, the ratio of inducer/helper cells: suppressor/cytotoxic cells remained normal as assessed by the use of the specific monoclonal antisera OKT4 and OKT8. Lymphocyte proliferation after mitogenic activation and the production of lymphocyte mitogenic factor by PWM stimulated lymphocytes was significantly depressed but was considerably improved by the removal of adherent cells. It appears as though an adherent suppressor cell was partially responsible for the depressed lymphocyte function observed in this patient.