A Comparison of the Immunologic Responses of Normal and Atopic Individuals to Parenterally Injected, Alum Precipitated Protein Antigen

Abstract

Twelve normal and 12 atopic individuals were immunized with an alum precipitated purified protein antigen followed by one or more "booster" injections or inhalations of the antigen in saline solution. They were observed for appearance of immediate wheal and erythema skin reactivity, occurrence of symptoms, and development of skin sensitizing and hema-gglutinating activity plusprecipitating antibody in the serum. No differences between the groups were noted in respect to immediate skin reactivity or symptoms after repeated exposure to this antigen. After several injections the sera of four highly sensitive individuals demonstrated a low titer of skin sensitizing antibody as determined by the Prausnitz-Kustner technique. One demonstrated a low titer of hemag-glutinating activity, and none revealed detectable circulating antibody by double diffusion precipitin tests in agar. These results suggest that the immunologic response of normal and atopic individuals to a parenterally injected protein antigen is similar. In the light of previous studies showing that only atopic individuals develop immediate skin reactivity after intranasal immunization with this antigen (crist-alline ribonuclease) these results further suggest that an essential difference between atopic and normal individuals lies in the mode with which protein antigen coming in contact with mucosal tissue is handled.