436 The Philippine Journal of Science 192s 



the complement-binding strength and the duration or extent of 

 lesions, and whether or not such relation proves to be directly- 

 proportional to the duration of treatment necessary to effect a 

 clinical cure. By titrating the sera in this way the test per- 

 formed at intervals during treatment may give, as does the 

 Wassermann reaction in syphilis and yaws, a measure of the 

 patient's response. Finally, we should seek to determine the 

 meaning of a negative reaction induced by treatment with 

 a view of more accurate individualization of treatment and de- 

 tention of patients. At the present time we have no way of 

 determining the state of infection in a leper who has become 

 clinically and bacteriologically negative; that is, we cannot deter- 

 mine whether he is completely cured or how long he must 

 continue under treatment to render him comparatively safe 

 from recurrence. It has been shown in these relatively few 

 observations that there is a wide variation immunologically 

 among the group of clinically cured, bacteriologically negative 

 cases, ranging from a strongly positive test to a negative com- 

 plement-fixation test. Further observations may show that 

 correspondingly important differences in the state of the infec- 

 tion also exist. 



SUMMARY 



1. The Wassermann reaction was found to be positive in 60 

 per cent of untreated nodular and mixed cases of leprosy and in 

 84 per cent of similar cases treated with chaulmoogra oil or its 

 products for a few months but still bacteriologically positive. 



2. In sixteen cases of nodular and mixed leprosy that had 

 become clinically and bacteriologically negative under treatment 

 with chaulmoogra oil the Wassermann reaction was uniformly 

 negative. 



3. One hundred per cent positive complement-fixation tests 

 were obtained in twenty-four cases of nodular, mixed, and 

 anaesthetic lepers, using an antigen composed of a suspension of 

 Bacillus tuberculosis (human). 



4. In twenty cases of nodular and mixed leprosy, clinically and 

 bacteriologically negative after treatment with chaulmoogra oil 

 or its products, two were negative, three gave complete fixation, 

 one was strongly positive, and fourteen weakly positive, with a 

 suspension of B. tuberculosis as antigen. 



5. The complement-fixation test with bacterial antigen prom- 

 ises to be of service as a means of measuring the response of 

 leprous patients to treatment. 



