HUMORAL IMMUNE-RESPONSES OF WORKERS OCCUPATIONALLY EXPOSED TO WHEAT-FLOUR

Wheat flour is a complex organic dust likely to induce immune response s when inhaled in work environment conditions. We compared the humoral status of 159 exposed workers from 11 flour mills and one industrial bakery with that of 41 workers from a salt factory. IgG, IgA, and IgM levels of antibodies to whole flour and to gliadin were assayed using ELISA tests in serum and saliva samples. Serum levels of IgG and IgA t o both antigens were significantly higher (p < 0.0001) in occupational ly exposed workers. Exposed workers had significantly higher levels of salivary IgG (p = 0.005) and IgA (p < 0.0001) to whole flour and of s alivary IgG (p = 0.0005) to gliadin. In both groups, similar levels of anti-gliadin salivary IgA antibodies were observed. These data sugges t that occupational exposure to wheat flour triggers specific immune r esponses, most likely through stimulation of the mucosal immune system . The presence of significant levels of serum antibodies, however, ind icates that a systemic immunologic response is also present among expo sed individuals. (C) 1994 Wiley-Liss, Inc.