Application of enzyme-linked immunosorbent assay (ELISA) in diagnosis of allergic bronchopulmonary aspergillosis.

IgE and IgG antibodies against Af were measured by ELISA in sera from 15 patients with ABPA and compared with antibody levels in six patients with extrinsic asthma and immediate-type skin reactivity to Af (prick skin test 3+ or 4+) but no other evidence for ABPA. The assay used polyvinyl microhemagglutination plates as a solid phase to adsorb antigens of Af and a double-antibody system of class-specific anti-human globulin and alkaline phosphatase-conjugated goat anti-rabbit globulin. IgE-Af and IgG-Af were significantly greater among patients with ABPA than in patients with asthma, suggesting that this assay may be used as an important diagnostic aid. The advantages of ELISA over radioimmunoassay are discussed in regard to early detection of an indolent pulmonary disease.