THERAPEUTIC IMMUNIZATION IN MAN 509 



respect to that existing in syphilis. Similar conditions have been 

 shown to prevail in Texas fever and Schilling believes that they may 

 be regarded as also existing to a certain extent in Malaria and Sleep- 

 ing Sickness. In both of these conditions complete spontaneous 

 sterilization of the body (without medicinal aid) is probably rare, 

 possibly does not occur at all, and the apparent immunity to rein- 

 fection is, as in syphilis, an evidence of persistence of the disease in a 

 latent form. 



In weighing the analogy of syphilis to such protozoan diseases, 

 one is inclined to wonder whether syphilis in man may be regarded 

 as at all spontaneously curable. So few are the cases left untreated 

 and so rarely does the reinfection occur even in the face of specific 

 remedies, that it seems to us more than likely that in syphilis, as in 

 Sleeping Sickness, a spontaneous "sterilizing" immunity does not 

 occur. This is a point, however, regarding which it is impossible 

 to gather data. 



In order to distinguish the conditions outlined above tersely from 

 the ordinary conception of immunity, Neisser 148 speaks of the altera- 

 tions which govern the reactions of the luetic body to freshly intro- 

 duced virus as "Anergie;" and "Umstimmung" or "Allergie" By 

 "Anergie" (a term first used by v. Pirqu'et and subsequently intro- 

 duced by Siebert in working out the analogy between pigeon-epitheli- 

 oma and syphilis), Neisser designates a condition of inability to 

 react by cellular change to contact with the virus. As he uses it, it 

 implies a passivity on the part of the invaded tissues (in which "die 

 Zellen auf die Spirochaeten schwer oder garnicht reagiren), by 

 which there is not necessarily a destruction of the invading trepone- 

 mata, and which, therefore, cannot in any sense be interpreted as a 

 "Schutz wirkung." By the "Umstimmung" of Neisser, the "change- 

 ment dans la mode de reaction" of Levaditi, is meant the changed 

 reaction capacity of the syphilized tissues which determines the char- 

 acters of the lesions at various stages of the disease. Thus it is 

 obvious that cellular reactions which result in the primary induration 

 are quite different from those which produce the tertiary gumma, 

 and that the histological changes of the roseola are distinct from 

 those of the serpiginous syphilide of the late stages. And since, as 

 we shall see, there is no valid reason to assume that the incitant has 

 been modified in virulence or vitality, we are forced to believe that 

 the reaction capacity of the body cells has been altered. 



Since it is a fact, then, that syphilitic infection so changes the 

 body tissues of man and monkeys that, during its course, resistance 

 to reinfection is produced, it should be possible to analyze this re- 

 sistance into its responsible factors and perhaps utilize the knowledge 

 so gained for practical therapeutic purposes. Before we proceed 



148 Neisser. Baermann u. Halberstaedfer d. med. Wchnschr., 1906, Nos. 

 1 and 3. 



