622 ANAPHYLAXIS IN RELATION TO INFECTION AND IMMUNITY 



reaction increases with progressive disease; is diminished with healing 

 and increased by reinfection. 



The clinical significance and practical value of skin reactions are 

 largely of a diagnostic nature for the detection of hypersensitiveness 

 to a protein or proteins, which may, when introduced into the organism, 

 produce various acute or chronic lesions and symptoms of disease. 



Anaphylactic Skin Reactions as Indices of Immunity. Of further 

 importance is the question of the clinical significance of a local anaphy- 

 lactic reaction as an index of immunity, that is, resistance to an infection 

 or reinfection. Is the anaphylactic antibody capable of attacking 

 and destroying the antigenic protein in a living state? Are protective 

 and curative antibodies produced by the defensive mechanism of the 

 body while the cells are being sensitized and the anaphylactic antibody 

 is being produced? In other words, is hypersensitiveness to be regarded 

 as an index of resistance? 



Romer 1 and Sata, 2 in experiments among cattle with Bacillus tuber- 

 culosis, reached the conclusion that a state of hypersensitiveness meant 

 a certain degree of resistance, while Krause 3 and Austrian 4 have ex- 

 pressed the opinion, based upon experiments, that sensitization of non- 

 tuberculous animals with tubercle protein does not raise their resistance 

 to experimental tuberculosis infection, and, indeed, may lower it. 



More recently Gay and Force 5 have greatly renewed interest in this 

 subject by advocating the skin test as a means of determining defensive 

 activity following typhoid fever or active immunization by means of 

 vaccines. Their first work was conducted with a "typhoidin" prepared 

 in the same manner as Koch's old tuberculin by cutaneous inoculation. 

 Later Gay and Claypole 6 prepared typhoidin by precipitating the so- 

 lution with alcohol, washing the precipitate with alcohol and ether, 

 drying in a vacuum, and suspending the resulting powder in phenolized 

 normal salt solution, which was injected intracutaneously and applied 

 cutaneously, a control powder being prepared from broth and used in 

 the same manner. With this skin test Gay and his associates have 

 studied the relative value of various vaccines and regard the anaphy- 

 lactic reaction as indicative of a state of immunity. Nichols 7 has 

 questioned the value of the anaphylactic skin test as an index of im- 

 munity and regards the typhoidin reaction as indicating nothing more 



1 Beitr. z. Klinik. d. Tuberk., 1908, xi, 79. 2 Ztsch. f. Tuberk., 1911, xviii, 1. 



3 Jour. Med. Research, 1911, xxiv, 361; find., 1916, 35, 1; 35. 



4 Bull. Johns Hopkins Hosp., 1913, xxiv, 11. 



6 Archiv. Int. Med., 1914, xiii, 471. 6 Archiv. Inter. Med., 1914, xiv, 671. 



7 Jour. Exper. Med,. 1915 ; xxii, 780. 



