SPECIFICITY OF ANAPHYLAXIS 563 



prefers the rectal injection, or, better still, the subcutaneous injection 

 of less than a fatal dose. 



The subject of anti-anaphylaxis is of great importance from its rela- 

 tion to serum therapy. No satisfactory method for producing this 

 state in a sensitized person has as yet been devised, owing, probably, to 

 the important quantitative factors shown, by the studies of Weil, to exist. 

 This subject will be discussed again in the following chapter, under the 

 head of Serum Sickness. 



The Mechanism of Anti-anaphylaxis. A true explanation of this 

 phenomenon cannot as yet be given. In the first place, the term anti- 

 anaphylaxis cannot be considered a proper one, as the animal is not 

 entirely and permanently anti-anaphylactic, but subsequently becomes 

 sensitive. The blood-serum of a refractory or anti-anaphylactic animal 

 does not confer a similar condition on a second sensitized animal. 



As previously stated, Friedberger believes that the refractory state 

 is due to neutralization or absorption of the anaphylactic antibody by 

 the antigen, but this explanation does not fit in with the facts, first, 

 because the serum of an anti-anaphylactic animal will still passively 

 sensitize a normal animal, and, secondly, as shown by Weil, passive 

 anaphylaxis of a guinea-pig, such as that induced by the injection of a 

 rabbit antihorse serum, may be prevented for at least eight days by a 

 previous injection of normal rabbit or sheep serum. In other words, 

 it would appear that normal rabbit and sheep serum may protect the 

 body-cells of the guinea-pig against the anaphylatoxin produced by 

 horse protein and horse anaphylactin or antibody. In explanation of 

 this paradoxic and non-specific reaction Weil, 1 who believes in the cel- 

 lular theory of anaphylaxis, has tentatively advanced the hypothesis 

 that the indifferent serum persists in the body-cells and markedly lowers 

 the reactivity of the cellular antibodies. 



SPECIFICITY OF ANAPHYLAXIS 



The anaphylactin, or so-called anaphylaxis antibody, displays quite 

 the same characteristics of specificity as do the other immune anti- 

 bodies, in that proteins of closely related species tend to interact, whereas 

 proteins of very distinct biologic or chemical nature are easily distin- 

 guished. In other words, the anaphylactic reaction is highly specific, and 

 of considerable value in the study and identification of different proteins. 

 For example, Dale has recommended the use of the graphic method in 



1 Jour. Med. Research, 1914, 30, No. 3, 299. 



