OPSONINS IN TUBERCULOSIS 291 



doubt that in certain cases of local conditions, such as lupus, 

 tubercular joints, glands, and genito-urinary tuberculosis, improve- 

 ment followed its application ; but where febrile conditions 

 indicated that general disturbances were in existence, there was 

 little justification for its being applied, and even in many local 

 conditions the absence of benefit was so marked that by many 

 physicians the method had been abandoned. 



Active Immunisation associated with Opsonic Observations. 

 The credit of rehabilitating the vaccine-therapy of tuberculosis 

 and of defining its scope belongs to Wright, who directed atten- 

 tion to the possibility of controlling the use of the tuberculin by 

 observations of its effect on the opsonic qualities of the serum. 

 Early in his work he showed that tubercle bacilli when sensitised 

 by an appropriate serum, were readily phagocyted by the poly- 

 morpho-nucleate leucocytes, and the relative sensitising capacities 

 of serum from tubercular and non-tubercular cases has been 

 widely studied. According to Wright, in strictly localised tuber- 

 culosis, the opsonic index is persistently low, varying from '1 to '9, 

 while in tuberculosis with general disturbances it fluctuates 

 greatly from day to day, being sometimes below, sometimes 

 above unity. To take the former and simpler case, he holds 

 that if the treatment with injections of tuberculin be controlled 

 by noting the effect produced on the opsonic index, great 

 improvement in the patient's condition may result. Wright's 

 interpretation of what occurs is briefly as follows : For 

 reasons unknown the opsonic qualities of the body fluids 

 may become abnormally low, and the tubercle bacilli, if 

 they gain admission to the body, can multiply locally. This 

 multiplication is associated with a still further local diminution 

 of the opsonins. By the introduction of such a substance 

 as tuberculin, the bodily mechanism, whatever it is, which 

 produces the opsonins is stimulated, and a rise in the general 

 opsonic index occurs. Naturally this is accompanied by a 

 passing to the site of infection of fluids more rich in opsonins 

 than previously, the activity of the phagocytes comes into play, 

 and the tubercle bacilli are destroyed. But any such vaccination 

 process must be controlled by constant observations of the 

 opsonic index, and it is only by this means, not only that good 

 results can be obtained, but that the production of harmful 

 effects can be prevented. The reason of this is that in a great 

 many cases the injection of a bacterial vaccine is followed by a 

 decrease in the opsonic qualities of the serum, the occurrence 

 of a negative phase. During such a period of depression there 

 is probably an increased susceptibility to the action of the 



