RESUMO
This study was conducted to compare the capacity of pigeon serum (PS), an antigen (Ag) associated with hypersensitivity pneumonitis (HP), and ovalbumin (OA) in the induction of immunologic lung disease in guinea pigs (gp). Whereas OA was very effective in inducing a severe pneumonitis, PS failed to produce significant disease. A determination of the antibody (Ab) responses in OA- or PS-sensitized GP revealed that total Ab activity, as well as specific IgG1, and IgG2 responses, were not significantly different in the two groups. There was, however, a markedly higher IgE-like Ab response to OA than to PS. Thus, there was a striking correlation between specific IgE synthesis and the production of immunologic lung disease. The disease resembled immune complex disease histologically, and we suggest that the IgE antibody may function as a preceding "anaphylactic trigger" mechanism for the lodging of complement-fixing Ag-Ab complexes in the vasculature of the lung. It is further suggested that PS may be a poor Ag for the induction of IgE synthesis in guinea pigs.
