OPTIMIZED PREPARATION OF ASPERGILLUS-FUMIGATUS EXTRACTS FOR ALLERGY DIAGNOSIS

Extracts of Aspergillus fumigatus are required for the measurement of specific antibodies that are important indices in the diagnosis of all ergic bronchopulmonary aspergillosis (ABPA). This study investigated t he effect of different culture conditions on the production and releas e of antigenic and allergenic proteins of A. fumigatus. Increasing the incubation temperature from 25-degrees-C to 37-degrees-C altered the production of proteins by the mycelium which resulted in the release o f a greater number of proteins that reacted with precipitating antibod ies. Static sporulating cultures produced a much wider antigenic spect rum than shake cultures although the number of precipitating proteins (5 and 3 respectively) and major IgE binding proteins (5 and 3 respect ively) was not greatly altered. The widest range of proteins bound by precipitating antibody or IgE from ABPA serum were released into the c ulture filtrate during 28 day static incubation at 37-degrees-C. The r esultant extract proved useful for screening patients for specific IgE and will provide a starting material for the identification of indivi dual antigens or allergens.