Effect of immunoglobulins on mineral dust-induced production of reactive oxygen metabolites by human macrophages.

Mineral dust-induced production of reactive oxygen metabolites (ROMs) by human monocyte-derived macrophages was investigated using lucigenin-dependent chemiluminescence. Chrysotile asbestos alone caused only weak ROM production by macrophages, but the addition of polyclonal immunoglobulin enhanced the reaction strongly. The phenomenon was seen with 1-, 4-, and 7-day-old cell cultures. Polyclonal immunoglobulin also slightly enhanced the ROM responses induced by amosite, crocidolite, and quartz dust. The enhancing effect could be achieved with several monoclonal immunoglobulins (isolated from the sera of myeloma patients), but IgA and IgG had the strongest effects. We suggest that immunoglobulins may interact with mineral dusts in a "nonimmunological," antigen-independent way and that the so-formed dust-immunoglobulin complexes may amplify the production of ROMs by inflammatory cells. This may explain a number of in vivo phenomena in which immune responses (for instance hypergammaglobulinemia and the presence of autoantibodies) have been shown to relate to the progression of mineral dust-induced pulmonary disease.