ANAPHYLACTIC OR ALLERGIC REACTIONS 619 



may be ascribed to the protein poison liberated, also to the liberated 

 endotoxins, if we consider these as separate from the protein poison. 



In antibacterial immunity, therefore, we recognize lysis or digestion 

 of the infecting bacteria by an antibody as the chief means of defense. 

 This antibody is produced by previous injection of the bacterial protein 

 in the form of a vaccine, or as the result of a previous infection. This 

 is true also of serum anaphylaxis, or of egg, milk, pollen, or any other 

 form of anaphylaxis, and in this way anaphylaxis is brought into rela- 

 tion with immunity. 



With the antibody in our body-fluids, the^ corresponding bacterium 

 is destroyed soon after it comes into contact with the antibody, but since 

 the amounts of protein poison and endotoxin released are small and 

 highly diluted, we experience none or but slight effects. If, however, 

 the infection or entrance of bacterial protein is strictly localized to a 

 small area, so that the liberated poisons are concentrated, a local reac- 

 tion is produced, such as is seen, for example, in the cutaneous tubercu- 

 lin, luetin, mallein, and similar reactions. 



The question may now arise as to the manner in which the body 

 cells dispose of, or become accustomed to, or are protected from the 

 protein poison and endotoxin. There is no satisfactory answer to this 

 question. We have seen that repeated injections of the same protein 

 lead to a condition of decreased sensitiveness. The method by which 

 endotoxins and the protein poison are neutralized, and whether anti- 

 bodies for these are produced, are points that require further investiga- 

 tion. This subject has been discussed in the preceding chapter, under 

 the head of Anti-anaphylaxis. It is true that our body-fluids may con- 

 tain large amounts of the antibody; that protein, bacterial or other, 

 may be vigorously split, but still we do not suffer from the effects of the 

 protein poison or endotoxins. Whatever the mechanism, it in some 

 manner concerns a neutralization or depression of the susceptibility or 

 hypersensitiveness of the body-cells; either the protein antigen is stored 

 in the cells and in some manner depresses cellular activity, as Weil 

 suggested, or else the protein is split beyond the toxic moiety by the 

 free amboceptor in the body-fluids, and in this manner prevents the 

 protein poison from reaching the sessile receptors (those amboceptors 

 still attached to the body-cells). This reasoning is based upon the 

 assumption that symptoms are produced only in case the poison be- 

 comes attached to the cells, according to the cellular theory of anaphy- 

 laxis (see the preceding chapter). 



