Infection and Allergy

Abstract

I. The modes of interactions between infection and allergy. Almost every infection is accompanied by allergy. The relationlhips between infection and allergy may be summerized as follows. A) Specific immunological processes accompanying infections. 1) Infectious agents or their products act as specific antigens. 2) Interactions between infectious agents and tissue components will probably produce some autoimmune lesions. For example, infectious agents may act as haptens or carriers to tissue components, or may have some cross reacting antigens with the latter. B) Non-specific effects of infections. 1) Adjuvant effects. Potentiation of the immunogenicity of antigens, alteration of the modes of sensitization (e.g. production of the delayed hypersitivity by protein antigens in tuberculous animals), liberation of the chemical mediators, increase of the sensitivity of target organs. 2) Modification of the immune response by way of antigenic competition. 3) Promoting the leakage of exogenous antigens into the body, or damage the segregation of autoantigens. II. Types of allergy related to infections. Though it was previously believed that infectious allergy was confined to the delayed allergy, now we can draw examples of any type of allergy from the consequenses of infections. Concerning our studies, we have shown that in bronchial asthma infectious agents could act as antigens producing immediate and sometimes Arthus type of allergy, and that the experimental hypersensitivity pneumonitis produced in sensitized animals by inhalation of bacterial antigens could have lesions of III or IV type of allergy according to the states or phases of sensitization. It was also found that long term bacterial sensitization (1.5-2 years) was necessary for the production of the lesions such as chronic glomerulonephritis, eventually it was suggested that some persistent infections or long term sensitizations might be the prerequisite conditions for the occurence of lesions like immune collagen disorders.