Immunochemical Mechanisms Involved in Penicillin Hypersensitivity in Experimental Animals and in Human Beings.

IN addition to its importance in clinical medicine, the human penicillin allergy system provides a comparatively well defined haptenic system for the study of fundamental immune mechanisms involved in human allergic diseases. Also, the understanding of the mechanisms involved in clinical allergic reactions to penicillin would in turn allow for more rational approaches to the prediction, diagnosis, prevention and management of these diseases. Penicillin allergies are, of course, immune diseases, i.e., they follow antibody/ antigen reactions taking place in relation to tissue. Accordingly, the following kinds of information are important in elucidating their immune mechanisms: (1) the chemical mechanism of antigenicity of penicillin; (2) the antigenic specificities of immune responses to penicillin; (3) the kinds and quantities of antibodies synthesized in response to the administration of penicillin and, (4) the relationship of the nature of the immune responses to the occurrence of clinical allergic reactions. Studies in experimental animals provided a basis for later studies in human beings, and broaden the biological significance of the results obtained. This paper will deal with the chemical mechanisms of antigenicity of penicillin, the antigenic specificities of the immune responses of guinea pigs, rabbits and human beings to administration of penicillin, our early views on the possible immune mechanisms involved in clinical allergic reactions to penicillin, and the clinical implications of these views.