282 IMMUNOLOGICAL METHODS OF DIAGNOSIS 



As regards the relation of the Wassermann reaction to the treat- 

 ment of syphilis with salvarsan or salvarsan in combination with 

 mercury, the majority of syphilographers are in accord in demanding 

 that the treatment be continued until a permanently negative Wasser- 

 mann is obtained and maintained (see section on Salvarsan). This 

 standpoint is in accord with the view that the Wassermann reaction 

 is a reaction of infection and not of immunity, and that the existence 

 of infection may be inferred so long as the reaction is demonstrable. 



The rapidity with which the reaction disappears under treatment 

 is quite variable. I have thus obtained a persistingly negative result 

 already after a single injection of salvarsan, while in other cases the 

 salvarsan in itself, though given repeatedly, was not able to cause 

 the reaction to disappear, whereas this promptly occurred, if mer- 

 curial treatment was instituted in addition. For further details of 

 this order, however, I must refer the reader to special works. 



In this connection it is interesting to note that Noguchi has 

 recently compared the findings obtained with the Wassermann 

 technique, i. e., with the use of lipoid antigen, with the results 

 which were obtained, when a pure culture of spirochetes was used 

 as antigen. I append some of the more important conclusions to 

 which these investigations gave rise: (1) The Wassermann reaction 

 is caused by the lipotropic substances, but not by the antibodies 

 which combine specifically with the pallida antigen; (2) the fixation 

 produced by the culture pallida antigen with certain syphilitic sera 

 is caused by the specific antibodies contained in the latter and may 

 constitute a specific diagnostic method for syphilis; (3) the fixation 

 caused by the syphilitic testicular extracts behaves like the culture 

 pallida extract in the majority of cases, but when the sera (syphilitic 

 or leprous) contain abundant lipotropic substances, it may give a 

 Wassermann reaction as well, which is not the case with the culture 

 pallida antigen; and, finally, (4) in the serum of rabbits with active 

 syphilitic orchitis there is no indication of the presence of a suffi- 

 cient amount of the antibodies for the pallida antigen, although 

 it gives a strong Wassermann reaction. It remains to be seen when 

 and under what conditions the specific antibodies for the pallida 

 will most abundantly be formed in syphilitic patients. At all events 

 it is rather remarkable that the amount of the antibodies detectable 

 by the pallida antigen in these cases was so small as compared with 

 certain other infectious diseases, in this respect. It is not improb- 



