Abstract Pigeons were immunized with bovine serum albumin and the subsequent antibody responses were characterized by several immunologic techniques. The antibody responses were delayed in onset, and 6 of 17 pigeons failed to produce detectable hemagglutinating antibody until after a second or third injection. Only 4 of 17 birds produced precipitating antibody. Mercaptoethanol-sensitive antibody persisted after the primary stimulus as the hemagglutination titers of some sera collected after the third injection could still be reduced by treatment. Immunoelectrophoresis and autoradiography revealed the presence of antibodies with mobilities similar to human IgG and IgM. A heat labile skin-sensitizing antibody was detected and had a minimum latent period of 24 hr and other characteristics similar to human homocytotropic antibody.

This investigation was carried out to characterize human precipitating antibody against several purified pigeon serum proteins using quantitative and direct isotope precipitin techniques, autoradiographic immunoelectrophoresis and passive cutaneous anaphylaxis. The results indicated that the human sera contained precipitating antibody, presumably only of the IgG class of immunoglobulins, which formed soluble antigen-antibody complexes in the zone of antibody excess. Pigeon γ globulin appeared to be more antigenic in man than pigeon serum albumin.

Fifty-eight poultry farmers were questioned for possible respiratory reactions suggesting a hypersensitivity reaction to chicken antigens. In addition, their sera were tested for the presence of antibodies against chicken antigens by several immunologic techniques. Of the poultry farmers examined, 57% had hemagglutinating antibodies in titers over 1: 80 against chicken antigens in their sera while none of ten controls had antibodies at a level of 1: 80. Furthermore, 27% of the poultry farmers had precipitins against chicken antigens in their sera, but no precipitating antibodies could be demonstrated in the sera from ten controls. No poultry farmer, however, had symptoms characteristic of a hypersensitivity pneumonitis following contact with chickens.