A solid-phase radioimmunoassay for the measurement of antibody to Aspergillus in invasive aspergillosis.

A solid-phase radioimmunoassay (SPRIA) to measure antibody responses to Aspergillus fumigatus and Aspergillus flavus antigens in invasive aspergillosis (IA) was developed and compared with immunodiffusion (ID) and counterimmunoelectrophoresis (CIE). SPRIA detected significant elevations in levels of aspergillus antibody in 15 (79)% of 19 patients with IA. Fewer patients with IA were positive by ID (give of 19) or CIE (four of 19). Only seven )8%) of 58 subjects with other fungal or bacterial infections were positive by SPRIA, as was one (5%) of 20 by ID and CIE. Weak cross-reactivity between aspergillus and candida antigens was demonstrated by SPRIA. IgG levels in patients with IA and control subjects were equivalent. Thus, an antibody response to Aspergillus can be detected in a greater percentage of patients with IA by SPRIA than by ID or CIE. Although a few patients without aspergillosis had elevated levels of aspergillus antibody, a rise in antibody level was specific for IA.