Antibodies

ANTIBODIES, according to Ehrlich's theory—substances that appear in serum upon penetration of an antigen (see) into the organism, i.e., during infectious diseases, during immunization with microbes and their toxins, during parenteral introduction into the organism of enzymes, proteins, as well as lipoids. With antigens, antibodies enter into a reaction that eliminates the effect of antigens on the organism or makes them accessible for further processing and detoxification. Ehrlich introduced the concept of the multiplicity of A.; since then, among them are distinguished antitoxins, agglutinins, precipitins, bacteriolysins, and others. According to the view of representatives of the physicochemical direction in the doctrine of immunity, however, immunobiological reactions (agglutination, precipitation, complement deviation reaction, etc.) are caused by one A., and the A. themselves represent not special substances in the sense of Ehrlich and Nicolle, but only a function or property associated with a change in the physicochemical state of the serum under the influence of immunization. Antibodies are specific; their combination with an antigen, according to Ehrlich, has a chemical, according to Bordet—a physicochemical, adsorption character.