ANAPHYLAXIS 401 



has been referred by Zinsser and Young 47 as possibly due to the 

 action of a protective colloid which prevents the union of the two. 



THE MECHANISM OF ANTI-ANAPHYLAXIS 



The conditions under which animals, previously anaphylactic, 

 may be rendered refractory or "anti-anaphy lactic" have been 

 discussed in another place. This condition is not entirely comparable 

 with immunity since it is a purely temporary state, lasting possibly a 

 few weeks, but after this the animals do not return to the normal 

 condition, but gradually become again moderately hypersusceptible. 

 (Rosenau and Anderson, Otto and others.) Thus a guinea pig 

 which has been sensitized, then rendered anti-anaphylactic by a mas- 

 sive injection of antigen, may react with mild symptoms to an in- 

 jection made 20 to 30 days later. Such returning sensitiveness, 

 according to Eosenau and Anderson, 48 is usually mild, fatal reac- 

 tions rarely occurring. 



An entirely satisfactory theory of anti-anaphylaxis has not yet 

 been advanced. 



Besredka, 49 as we have seen, believes that the anaphylactic reac- 

 tion takes place by the union of the toxic factor in the serum (anti- 

 sensibilisin) with a specific antibody sessile upon the cells of the 

 central nervous system. If the antigen is injected slowly or in small 

 amount these sessile receptors are gradually united to antigen with- 

 out fatal shock, and the animal is thereby rendered insensitive. 



In his own words, this "desensitization" amounts to a return of 

 the cells to their normal preanaphylactic or naturally insensitive 

 condition. With the refutation of his theory of anaphylaxis, his 

 theory of anti-anaphylaxis also falls to the ground, and neither of the 

 two can be accepted as valid at present. 



If we look upon anaphylaxis as a reaction taking place entirely in 

 the circulation we may accept, with Rosenau and Anderson, 50 Fried- 

 berger, and others the explanation that anti-anaphylaxis is due to a 

 saturation of the anaphylactic antibody with antigen. Hypersus- 

 ceptibility is then subsequently reestablished because a gradual 

 formation of circulating antibody continues, and eventually free 

 antibody will again be present in the blood. This view is only in 

 part satisfactory, as Friedemann 51 points out. For it does not 



47 Zinsser and Young. Jour. Exp. Med., Vol. 17, 1913. 



48 Rosenau and Anderson. U. S. Pub. Health and M. H. S. Hyg. Lab. 

 Bull. 36, 1907. 



49 See Besredka, "Kraus u. Levaditi Handbuch, etc.," Erganzungsband 1, 

 p. 246. 



50 Rosenau and Anderson. U. S. Pub. Health and M. H. S. Hyg. Lab. 

 Bull. 64, 1910. 



51 Friedemann. "Frei Vereinigung f. Mikrobiol.," Berlin, 1910. Ref. 

 Centralbl. Bakt. I, Vol. 47; Beiheft, p. 1, 1910. 



