Bacterial allergy and tissue reactions.

Abstract

The bacterial allergies, though they are phenomena of relatively specific hypersusceptibility, differ in certain fundamental respects from true protein anaphylaxis. Our own investigations on this subject have dealt chiefly with the tuberculin reaction in regard to which it seems safe to state that: 1. Tuberculin allergy as manifested by the intracutaneous reaction may occur without general anaphylaxis to tuberculoprotein, and vice versa. 2. The active principle of tuberculin which elicits reactions in the sensitive subject is not a protein. 3. Tuberculin sensitiveness seems inseparably associated with the reactions of the animal tissues to the tubercle bacilli or their constituents; in other words, after prolonged experimentation, we arrive again at the recognition that there is no tuberculin sensitiveness without a tubercle. Here again the fact that the tuberculin reaction is merely the classical example of the bacterial allergies in general is apparent in that our own work with other bacteria as well as especially that of Fleischner and Meyer with bacillus abortus has indicated that bacterial allergy is associated with infection rather than with the type of immunization with soluble bacterial substances which leads to antibody formation without necessarily active focal inflammatory reactions. In the case of the tubercle bacillus Petroff and the writer have shown that the injection of the dead bacilli induces tuberculin allergy quite effeotively, probably because of the insolubility of these organisms, in consequence of which the dead organisms lead to tubercle formation essentially analogous to that induced by the living. This point, apart from its possible practical imterest, is theoretically significant in that it indicates that, in the association of bacterial allergy with infection rather than with irqmunization, it is the tissue reaction which is of importance rather than any differences in the products which pass into the infected animal from dead and living bacteria respectively.