Nonspecific suppressor cell function in atopic subjects

The status of concanavalin A (Con A)-nonspecific suppressor cell function and histamine-receptor-carrying mononuclear cells in 19 allergic and 27 nonallergic individuals was investigated. No differences were detected between the two groups with respect to suppression by Con A-activated suppressor cells of polyvalent IgG biosynthesis, IgG secretion, or mitogen-induced proliferative responses. Histamine-receptor-carrying cells of the allergic subjects were numerically equal to those of the nonallergic subjects. Mononuclear cells from the allergic group, however, required a higher dose of histamine than did those for the nonallergic group to induce suppression in vitro (p < 0.02 for 10 −4 M histamine and p < 0.05 for 10 −3 M histamine). Plasma from the allergic group contained higher levels of histamine activity (p < 0.05). Plasma from either allergic or normal groups did not affect histamine activity in vitro. There are no apparent functional abnormalities of antigen-nonspecific mononuclear cells in the allergic patients with respect to non-IgE-mediated in vitro parameters. The demonstrated dysfunction of histamine-receptor-carrying cells could be attributed to high levels of circulating histamine that could result in receptor modulation in vivo. More work is needed to clarify the status of antigen-nonspecific and antigen-specific suppressor cells that regulate IgE biosynthesis in allergic states.