Identification of IgE-binding components in occupational asthma caused by corn dust.

Abstract

BACKGROUND: There have been some reports of corn dust-induced occupational asthma that suggest nonimmunologic mechanism. In this paper, we present a case of occupational asthma and rhinitis caused by corn dust where bronchoconstriction was induced by an IgE-mediated reaction.

METHODS AND RESULTS: The patient had positive responses to weed and grass pollens as well as corn dust extracts. The bronchoprovocation test elicited an early asthmatic response to corn dust extracts. Serum-specific IgE and IgG4 antibodies to corn dust extracts were detected by enzyme-linked immunosorbent assay (ELISA). In order to identify further the allergenic component of the extracts, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and electroblotting studies were performed. Ten IgE-binding components (9 to 140 kD) were detected within the corn dust extracts.

CONCLUSION: These results suggest that inhalation of corn dust can cause IgE-mediated bronchoconstriction in an exposed worker.