Studies were made by
enzyme linked
immunosorbent assay (ELISA) and indirect fluorescent antibody (IFA) tests on the reactivities and specificities of 13
antigens prepared from four species of Aspergillus against
antisera from immunized rabbits and 64 sera from patients with
aspergillosis, other systemic
mycoses and
nocardiosis. Although reactions in both serological tests were invariably strongest with homologous
antigen: antibody systems,
antisera from rabbits immunized with A. fumigatus, Blastomyces dermatitidis, Candida albicans and Paracoccidioides brasiliensis reacted in the ELISA test with all of the Aspergillus
antigens. In contrast, cross-reactivity was virtually non-existent with antiserum to Histoplasma capsulatum. Of five
antigens prepared from A fumigatus tested by ELISA against human sera from patients with
aspergillosis and other nocardial and systemic
fungal infections, sensitivities varied from 81 to 100% for sera from 32 patients with
aspergillosis, and specificities from 20 to 97% for sera from 30 patients with
nocardiosis and other systemic
mycoses. Purified A. fumigatus C
antigen reacted weakly with sera from eight of these 30 patients, but the reactions were readily distinguishable from those obtained with sera from patients with
aspergillosis. At optimal serum dilutions, cross-reactivities of A. fumigatus in the IFA studies were non-existent in the sera from 28 patients with candidosis,
coccidioidomycosis,
cryptococcosis,
histoplasmosis,
paracoccidioidomycosis and
nocardiosis. Sensitivities of IFA were 94% for patients with aspergilloma and 83% for patients with
allergic bronchopulmonary aspergillosis.