Suppressor Cell Activity in a Male Infant with T‐ and B‐Lymphocyte Dysfunction Treated with Thymosin

Abstract

A male infant with bilateral iris coloboma who previously had repeated infections and malabsorption was studied. The levels of total lymphocytes and of T [thymus-derived] and B [bone marrow-derived] cells were normal or high, but IgA [immunoglobulin A] became undetectable and IgG low; IgM was normal. His lymphocytes did not respond to phytohemagglutinin (PHA), concanavalin A, pokeweed mitogen (PWM) or in mixed lymphocyte reactions (MLR), nor did they respond in vitro when thymosin was included in the test systems. He was skin-test-negative, even to dinitrochlorobenzene. His crudely isolated T lymphocytes and the supernatant of his PHA-stimulated lymphocytes inhibited the response of normal lymphocytes to PHA, PWM and in MLR. During thymosin treatment, skin tests and lymphocyte reactivity to mitogen remained negative. He became faintly positive to MLR, and the suppressor activity in the supernatant of his PHA-stimulated lymphocytes no longer inhibited the response of normal lymphocytes to PHA, PWM or in MLR. In parallel with thymosin treatment, he showed quite marked clinical improvement.