Immunological evaluation of patients with beta-thalassemia major

Abnormalities in the immune system and zi nc homeostasis in patients with P -thalassemia major (TM) have been reported. Since zinc ion is essential for the efficiency of the immune system and is required to induce biological a ctivity to thymulin (Zn-FTS), a biochemically defined thymic hormone, we in vestigated the plasma levels of zinc and both active thymulin (Zn-FTS) and total zinc saturable thymulin (Zn-FTS+FTS) in 18 patients with TM aged betw een 2 and 31 years and 22 normal controls of the same age, Inhibitory molec ules anti-thymulin and the distribution of lymphocyte subsets were also ana lyzed. Patients with TM presented significantly lowered plasma zinc and thy mulin levels when compared to normal subjects, The significant enhancement of the active form of the hormone after zinc addition in vitro suggests tha t low thymulin values found in TM are due not to a thymic failure in synthe sizing and secreting the thymic hormone, but a defect in zinc saturation of the hormone. An impairment of cell subset distribution was also demonstrat ed. This study shows that zinc and thymulin deficiency contribute to the co mplex mechanisms underlying immune dysfunction in TM. Copyright (C) 2001 S. Karger AG,Basel.