MODIFICATIONS OF THE WASSERMANN REACTION 485 



accurate quantitative test. (See p. 470.) They claim that with their 

 modified technic the results secured are practically the same with the 

 antiox and antisheep systems, although the human serums contain 

 much less natural antiox amboceptor and, theoretically, therefore this 

 system is better. 



MODIFICATION OF VON DUNGERN 



More recently von Dungern has proposed a modification similar to 

 that of Noguchi. Like Tchernogubou, he uses active serum only, and 

 utilizes the patient's own blood-cells. The blood is defibrinated and 

 used in doses of 0. 1 c.c. Complement in the human blood is disregarded, 

 and is furnished by guinea-pig serum in dried-paper form. Alcoholic 

 extract of syphilitic liver is used as antigen, and this opens up an avenue 

 for false positive or proteotropic reactions to creep in. Antihuman 

 amboceptor is prepared by immunizing goats, but, as Noguchi has shown, 

 this amboceptor gives a much weaker hemolytic reaction than that de- 

 rived from the rabbit. Von Dungern generally omits the important 

 control with known syphilitic serum; there is no direct control on the 

 antigen, and old bloods cannot be used. 



THE WASSERMANN REACTION IN THE VARIOUS STAGES OF SYPHILIS 

 1. In Primary Syphilis. As would be expected, a certain degree of 

 tissue change most occur before syphilis reagin appears in the blood. 

 Even with the best technic there is a limit to the sensitiveness of the 

 Wassermann reaction, so that while the reagin may be produced at the 

 very onset of an infection, time and further tissue changes are required 

 before sufficient reagin is produced to yield a complement-fixation 

 reaction. 



Since, therefore, the results of the Wassermann reaction in primary 

 syphilis are dependent upon the virulence of the infection, the time at 

 which the reaction is made, and the delicacy of the technic, it is not 

 surprising that the results of different investigators vary in the propor- 

 tion of positive reactions obtained. While positive reactions have been 

 said to have been secured before the appearance of the initial lesion, 

 these are rare, and there is always the likelihood that an earlier infection 

 was overlooked. A careful review of our own work and the literature 

 upon this subject establishes the following: 



(a) A positive reaction may be secured during the first week after 

 the appearance of the chancre. Craig has reported a positive reaction 

 occurring five days after the appearance of the initial lesion. Levaditi, 

 Laroche and Yamanouchi, and others have recorded many positive 



