Allergenic components of Aspergillus fumigatus determined by radioimmunoprecipitation.

The allergenic components of Aspergillus fumigatus were identified using radioimmunoprecipitation (RIP) assay. Sera from 20 asthmatic children with positive skin tests to A. fumigatus were used for assay. Immune complexes formed between iodinated A. fumigatus and IgE antibodies in patients' sera were precipitated by immobilized anti-IgE monoclonal antibodies (MAbs). The precipitates were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and analyzed by autoradiography. It was found that IgE antibodies in the sera of allergic individuals reacted with several allergenic components of A. fumigatus ranging from 10 to 125 kD. Proteins of 38, 33, and 68 kD were recognized by IgEs from the allergic sera with frequencies of 85%, 65%, and 40%, respectively. It appears that these are the major allergenic components of A. fumigatus.