CHAPTER XX 



THE WASSERMANN REACTION FOR THE DIAGNOSIS OF 



SYPHILIS 



THIS now popular and fairly reliable method for. assisting in 

 the diagnosis of atypical syphilitic infections was devised by Wasser- 

 mann, Neisser, and Bruck.* It is a method of making the diagnosis 

 of syphilis by demonstrating in the blood (cerebrospinal fluid, milk, 

 or urine) of the patient a complement-fixing substance (antibody?) 

 not present in normal blood. 



The test is twofold: (i) A combination of syphilitic antigen, 

 complement, and suspected serum. (2) A subsequent addition to 

 the mixture of blood-corpuscles and hemolytic amboceptor. If the 

 suspected serum contain the syphilitic antibody the antigen and 

 complement unite with it, and the complement being thus "fixed," 

 no hemolysis can take place upon the subsequent addition of the 

 blood-corpuscles and hemolytic serum. If, on the other hand, the 

 suspected serum contain no antibody, the complement cannot be 

 fixed, and is, therefore, free to act upon the subsequently added 

 blood-corpuscles in the presence of the hemolytic serum, and hemo- 

 lysis results. 



It is thus seen that the first test is made for the purpose of fixing 

 the complement, and the second for the purpose of finding out 

 whether it has been fixed or not. 



It is quite clear that such a test is very delicate, and can only 

 be successful when executed with great precision and with reagents 

 or factors titrated, so that their exact value may be known. 



CONSIDERATION OF THE REAGENTS EMPLOYED 



I. For the first, or fixation, test it is necessary to bring together 



Syphilitic antigen. 



Serum to be tested. 



Complement. 



(i) The Syphilitic Antigen. It was supposed by Wassermann, 

 Neisser, and Bruck, who first devised the test, that the syphilitic 

 antigen must contain the essential micro-organisms of syphilis. No 

 method for the cultivation of Treponema pallidum having at that 

 time been devised, cultures of the specific micro-organism could not 

 be employed. Histologists had, however, shown that greater num- 

 bers of the organisms were to be found in the livers of the congen- 

 itally syphilitic stillborn infants than anywhere else. With the 



* "Deutsch. Med. Wochenschr.," 1906, No. 19. 

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