Mechanism of Allergy in Tuberculosis.

Abstract

These experiments are part of an investigation into the mechanism of allergy in tuberculosis and its relation to immunity. This report is concerned with the problem of individual cell sensitiveness in the allergic animal.

The tuberculin reaction and the allergic lesions occurring in the body during the progress of infection are generally regarded as being, most probably, the result of an antigen-antibody reaction, in which bacillary products react with an antibody formed during the course of the infection. Rich and McCordock have been unsuccessful in attempts to demonstrate satisfactorily, in vivo, the presence of such an antibody in the plasma of allergic animals, and this has been the experience of others who have recently made similar attempts. The surmise has therefore arisen that if an antibody-antigen reaction is indeed responsible for the allergic inflammation and necrosis, this reaction probably takes place in or on the cells themselves, to which the antibody may be bound.

It has never been proven, however, that the isolated cells of the allergic body are really changed in a manner which renders them more sensitive than normal cells to the effects of the products of the tubercle bacillus. Studies in vivo are complicated by the presence of the body fluids, by circulatory changes, by uncontrollable variations in antigen concentration which result from the local fixation of the antigen in allergic animals, and by other factors. The purpose of the present experiments was, therefore, to test the sensitiveness of isolated cells to tuberculin in vitro, in a manner which might give us information as to whether or not the individual cells of the allergic body become altered in such a way that, regardless of the medium by which they are surrounded, they will be damaged by a given amount of tuberculin more readily than normal cells.