Selenium and immune functions in humans

Abstract

Volunteers (40) from a population with low serum Se concentrations were supplemented with Se or placebo for 11 wk. Blood samples were drawn at intervals for analysis of Se status and immune function. At the end of the supplementation period, plasma Se levels were 74 ng/ml in the placebo group and 169 ng/ml in the supplemented group. The improvement in Se status was associated with a 57% increase in the activity of platelet glutathione peroxidase; there was no increase in the activity of this enzyme in the placebo-treated subjects. Immune function was measured in vitro by tests of lymphocyte and granulocyte activity. Intracellular killing of Staphylococcus aureus by granulocytes was slightly lower in the placebo group than in the Se group at the end of the supplementation period (77.2 cf 85.2%; P < 0.05). No significant changes were observed in phagocytosis, chemotactic factor generation, antibody or leukocyte migration inhibitory factor production by lymphocytes, or in proliferative responses to phytohemagglutinin or concanavalin A. Evidently, Se deficiency of the order found in Finland and some other areas of the world has little, if any, influence on the immune functions measured in this study.