i66 



METHOD OF COMPLEMENT FIXATION 



There is no doubt, however, that this exceptional view is incorrect. It is true that 

 the real syphilitic antigen is unknown, but most probably it is neither the pure spiro- 

 chaetes nor a pure lipoid substance. The author has expressed the hypothesis that the 

 antibody producing antigen is a toxolipoid. This explains the fact that pure lipoids 

 cannot stimulate any antibodies, but can react nevertheless with luetic antibodies in 

 vitro. 



The accompanying diagram (Fig. 17) explains this hypothesis. In 

 order to answer the objections raised against such a theory, the author has 

 proposed the indifferent term of "Lueseargine" for the luetic antibodies, as 

 long as their biological structure is unknown. 



Experiments by Citron and Munk 

 prove without any doubt that the 



Lues-Antigen { ^ luesreagine is a true antibody of an an- 



tigen contained only within the aqueous 

 syphilitic extract. Aqueous and alco- 

 holic extracts of normal organs do not 

 contain this antigen. Rabbits were im-' 

 munized with various antigens. Only 

 those injected with watery syphilitic 

 extracts developed antibodies similar 

 to the luesreagines of human syphilis 

 in that they reacted with alcoholic 

 normal extracts. Blumenthal and 

 Meyer corroborated these findings and further showed that even the alco- 

 holic syphilitic extracts do not contain this antigen. 



Since the cultivation of the spirochetes in pure culture has been 

 simplified by Noguchi, extracts of such cultures have been made and 

 employed as antigens for the Wassermann reaction. It was hoped that 

 if such a specific and efficient antigen could be obtained, the basis of 

 a^true antigen antibody reaction would be more certain. While fixation 

 occurs with the pallida culture antigen, the results cannot be depended 

 upon for clinical purposes; some cases of undoubted syphilis giving a 

 strongly positive reaction with the syphilitic liver antigen, give abso- 

 lutely negative results with the culture antigen (Craig and Nichols). 



Independent of the question of " biological specificity," the Wasser- 

 mann reaction must also be considered in the light of " clinical specificity." 

 From this standpoint it fulfills its demands. With only few exceptions, it 

 can be regarded as absolutely specific for lues. 



The well established exceptions are, frambcesis, trypanosomiasis, leprosy, malaria, 

 scarlet fever, febris recurrens. The reactions obtained here are similar, but not the 

 same as those obtained in syphilis. In leprosy the difference is that the reac- 

 tion can also be performed with tuberculin as antigen; in scarlet fever the reaction 

 appears only in a small percentage of cases and not with all luetic extracts. Further- 



