CHAPTER XIX. 



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 Wassermann, 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 nor- 

 mal blood. 



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

 antigen, complement, and suspected serum. (2) A subse- 

 quent addition to the mixture of blood-corpuscles and hemo- 

 lytic 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-cor- 

 puscles and hemolytic serum. If, on the other hand, the sus- 

 pected 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 hemolysis 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. 



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



