Evaluation of allergenicity of egg yolk immunoglobulin Y and other egg proteins by passive cutaneous anaphylaxis

The allergenicity of egg yolk immunoglobulin (IgY) was studied using passiv e cutaneous anaphylaxis. It was observed that the intact yolk, water solubl e fraction of the yolk, whole IgY molecule or its antigen binding (Fab') an d crystallizable (pFc') fragments produced by pepsin digestion, elicited lo w IgE antibody response in mice when compared to egg white, a known allerge n. The pFc' fragment of IgY was more antigenic than the Fab' fragment as de termined by ELISA. Low cross-reactivity was also observed between the egg y olk proteins and egg white antibodies. The low IgE antibody response to the egg yolk proteins was associated with a higher suppressor T-lymphocytes or lower helper T-lymphocytes, or both, in comparison to egg white derived ly mphocytes.