590 ANAPHYLAXIS 



evidence of the role played by the protein split products in the produc- 

 tion of acute anaphylaxis has apparently been furnished. These results 

 however, cannot at the present time be regarded as final. Pearce and 

 Williams, 1 in a similar study with horse serum, employing the dialysis 

 technic and using ninhydrin as the indicator, were unable to demonstrate 

 the presence of the ferments after sensitization, although by using large 

 amounts of serum secured after anaphylactic shock had occurred they 

 observed positive reactions, which may have been due, in part at least, 

 to the presence of cleavage products. Zunz 8 found that the protein- 

 splitting properties of blood-serum, as tested on the sensitizing protein, 

 increased in the anaphylactic state from the fifth to the twentieth and 

 sixtieth day, and were not recognizable in blood-serum taken during 

 or soon after anaphylactic shock occurred. Pfeiffer and Mita and 

 Vaughan have observed the apparent disappearance of the ferment from 

 the blood, even though the animal is sensitized, and the last-named 

 observer explains this on the assumption that the ferment comes from 

 the fixed cells, which are stimulated to elaborate the ferment only when 

 the specific protein is brought into contact with them. 



One of the older theories of anaphylaxis regards the process as a 

 precipitin reaction. It is apparent that, in the serum of an animal 

 immunized with a soluble protein, such as a serum, a precipitin and com- 

 plement-fixing body, presumably an albuminolysin or so-called " fer- 

 ment, " are produced, and exist together in the immune serum. While 

 the role of precipitins themselves appear to have been excluded as directly 

 participating in the production of anaphylactic shock, recent experi- 

 ments of Zinsser and others would tend to show that a precipitin 

 possesses the nature of a protein sensitizer or antibody that sensitizes 

 its antigen, just as a hemolytic amboceptor sensitizes its corpuscles, 

 precipitation being a secondary phenomenon due to the colloidal nature 

 of the reacting bodies under conditions of quantitative proportions and 

 environment that favor precipitation. This would assign to the pre- 

 cipitins and agglutinins an active though secondary role in the processes 

 of anaphylaxis and immunity. 



At the present time, therefore, we may tentatively assume that the 

 anaphylactin or allergin is of the nature of a specific lytic amboceptor 

 or albuminolysin, which, in conjunction with non-specific complement, 

 constitutes what is called a "ferment," and is capable of splitting a 

 protein molecule with the liberation or formation of a toxic moiety re- 

 sponsible for the lesions and symptoms of anaphylaxis. Just as other 



1 Jour. Infect. Dis., 1914, 14, 351. 2 Zeitschr. f. Immunitatsf., 1913, 17, 241. 



