Antigens/allergens of Aspergillus fumigatus. Identification of antigenic components reacting with both IgG and IgE antibodies of patients with allergic bronchopulmonary aspergillosis

Evidence that both IgE and IgG antibodies present in the sera of allergic bronchopulmonary aspergillosis patients (ABPA) combine with several of the antigenic components of Aspergillus fumigatus has been obtained using a self-crossed radioimmunoelectrophoresis test. In this test, patient's serum was used to develop its own crossed immunoprecipitation pattern to a reference antigen before proceeding to autoradiography with 125I-anti-human IgE in the usual way. Comparison of autoradiograph with immunoprecipitate showed a varied pattern of reactivity, i.e. precipitin peaks with and without associated radioactivity, as well as some peaks appearing only in the autoradiograph. Control sera, including sera from A. fumigatus skin test positive patients and a skin test negative aspergilloma patient with multiple precipitins showed no such combined activity. The specificity of the test was further demonstrated using an ABPA serum pool, both by absorbing the IgE from the serum before incorporation in the gel and also by heat inactivation (56 degrees C, 4 h) of the serum to destroy the heat labile determinants on IgE molecules, thus preventing the uptake of the anti-IgE specific for these determinants.