Identification and partial characterization of diagnostically relevant antigens of Aspergillus fumigatus

Metabolic antigens of Aspergillus fumigatus, soil strain 2605 and sputum isolate, were evaluated for their diagnostic applicability using hyperimmune sera and sera of adults and pediatric patients of allergic bronchopulmonary aspergillosis. An indirect ELISA was standardised by using 2-10 micrograms/ml of coating antigen for detection of specific IgG and IgE antibodies in the sera of patients. The ratios of absorbance for specific IgE and IgG antibodies by ELISA (normal to patients) were observed to be in the range of 1:2 to 1:3 to 1:8 respectively. These antigenic preparations were further analyzed to identify and characterize the individual components by immunoblotting. This analysis indicated the presence of allergenic and antigenic determinants in the antigens of molecular weights 70, 34, and 28 Kd. The utility of the antigens of soil strain for diagnostic purpose is suggested.