Iodide enhances IgG synthesis by human peripheral blood lymphocytes in vitro

Several studies have suggested that iodide may increase thyroiditis and autoantibody synthesis. We have investigated the effect of iodide in vitro at physiologically relevant concentrations on immunoglobulin synthesis by normal human peripheral blood lymphocytes stimulated with pokeweed mitogen. Both the number of cells which synthesised IgG and the amount of IgG released into the culture supernatant increased significantly after culture in a medium with added iodide compared to a medium with added chloride. No effect of increasing concentrations of the added iodide from 10(-3) mM to 10 mM was observed. These findings suggest that iodides may have a role in enhancing antibody synthesis which may be important when programmes of iodide supplementation are introduced into areas which are deficient.