Abstract
Studies of sera from patients with bronchopulmonary allergic aspergillosis (BPAA) confirm a previous report that serum IgE concentrations are elevated. Both IgE and IgG antibodies against Aspergillus fumigatus antigen (AF Ag) can be detected in vitro using a solid phase radioimmunoadsorbent technique. Sera were studied by several techniques to determine if the elevated serum IgE concentrations in BPAA were composed primarily of IgE antibodies directed against AF Ag. The results indicated that the opposite is more likely: that most of the IgE in the sera obtained from patients with BPAA and used in these studies is not directed against AE Ag.