Methyldopa Inhibition of Suppressor-Lymphocyte Function

Publisher Website
Google Scholar
Abstract
To test the hypothesis that methyldopa induces red-cell autoantibodies by inhibiting the activity of suppressor lymphocytes, we studied its effect on several immune functions. Methyldopa inhibited T-lymphocyte suppression of IgG production by peripheral-blood mononuclear cells stimulated by pokeweed mitogens. This effect occurred in isolated T cells incubated with methyldopa and in T cells obtained from patients taking methyldopa. In addition, the drug caused a 30 to 80 per cent reduction in the proliferative response of peripheral-blood mononuclear cells to mitogens in vitro, and this reduction primarily involved the activation of T lymphocytes. Methyldopa also caused a persistent elevation of intracellular lymphocyte cyclic AMP in vitro and in vivo. We postulate that methyldopa alters the immune system by causing a persistent increase in lymphocyte cyclic AMP, which inhibits suppressor T-cell function. These effects may lead to unregulated autoantibody production by B cells in some patients. (N Engl J Med. 1980; 302:825–32.)