Bacillus Calmette-Guérin (BCG) and immunoglobulins synergistically enhance mineral dust-induced production of reactive oxygen metabolites by human monocytes.

The modulating effect of BCG and polyclonal immunoglobulin on mineral dust-induced production of reactive oxygen metabolites (ROM) by human monocytes was studied using luminol-dependent chemiluminescence. BCG and immunoglobulin synergistically amplified the ROM production induced by chrysotile asbestos and quartz particles, and BCG caused a sharper dose response for poly-immunoglobulin added to the mineral dusts. Immunoglobulins did not affect zymosan yeast-induced ROM production, which was enhanced strongly by BCG. As there is evidence that phagocyte-derived ROM are of importance in mineral dust-induced lung injury, we suggest that the observed synergism between host response inflammatory mediators (poly-immunoglobulin) and exogenic irritants (BCG) may contribute to the outcome of exposure of mineral dusts, and thus in part explain the individual variations in susceptibility to mineral dust-induced diseases.