184 PRACTICAL METHODS IN IMMUNITY 



General Considerations. Cherry thinks anticomplementary bodies are found 

 during chloroform anaesthesia. If the antigen should also have anticomplementary 

 action the total might give a negative result. 



By heating the serum for half an hour at s6C. (inactivation) the positive results 

 reported to have been obtained in certain cases of cancer, nephritis, scarlet fever, 

 leprosy and tuberculosis may be avoided; the syphilitic antibody alone being more 

 thermostable. The thermostability of serum of inherited syphilis is the highest 

 that of primary syphilis the least of luetic sera. 



McDonagh states that in the primary stage the Wassermann is positive in 40% of 

 cases. In secondary cases 97% give positive results when treatment has not been 

 instituted. In tertiary syphilis about 70% are positive. 



In 268 cases at the medical clinic of Johns Hopkins Hospital, Clough 

 failed to obtain a positive reaction in 99 cases which were negative 

 clinically. 



In 45 cases of syphilis he obtained 73% of positive results. Ex- 

 cluding cases which had received thorough treatment 82% were 

 positive. Tabes gave 40% and general paresis 100%. In five cases 

 of primary syphilis four gave positive reactions. Kolmer gives 96% 

 positives for untreated active tertiary syphilis with 75 to 80% for 

 latent tertiary syphilis. In untreated congenital syphilis of children 

 over one year of age, 97 to 100%. Comparing the luetin reaction 

 with the Wassermann, Noguchi gives 80% for tertiary and 70% 

 positive for congenital syphilis. 



Based upon the observation of Bauer, that human serum contains haemolytic 

 amboceptors for sheep corpuscles, and of Hecht, that the complement normally 

 present in human serum would suffice without the addition of guinea-pig serum 

 complement, the following method of Fleming is easy of application, but not 

 recommended. 



For the test we use: 



1. Alcoholic extract of rabbit's heart, made by washing the recently removed 

 heart with salt solution to remove all blood. Cut into small pieces and grind in a 

 mortar with sand and for every gram of heart add 5 c.c. of 95% alcohol. Keep the 

 mixture at a temperature of 6oC. for two hours and filter. This is the stock solu- 

 tion. For use dilute it 10 times with normal salt solution. 



2. A 5% emulsion of washed sheep red cells, prepared as for the Wassermann test. 



3. Suspected and control sera. 



With a capillary bulb pipette take up i part of serum and 4 parts of the heart 

 antigen, mix on a glass slide, again draw up into the capillary pipette and, 

 leaving a separating air space, next draw up i part of 5% emulsion of sheep red 

 cells. Then seal off tip of pipette and incubate at 37C. for one hour. Now file 

 off tip and mix the red cells with the serum and antigen and again draw up into the 

 capillary pipette and incubate a second time for two hours. Haemolysis or the 

 reverse is shown in the fluid overlying the cell sediment. Various controls should 

 be made using normal and known syphilitic sera; also with normal salt instead of 

 serum. 



