296 TUBERCULOSIS 



quiescent lung affection a tuberculin injection causes increased 

 cough, increase of expectoration, or slight rise of temperature, the 

 dose given has been too large, and the same is true if in a 

 tuberculosis about the bladder symptoms of urinary irritation 

 supervene. While undoubtedly in many cases good results have 

 been obtained, every administration must be looked upon as of 

 the nature of an experiment, and the treatment should only be 

 in the hands of those who have had great experience of the 

 subject. 



The fact that in so many cases tubercular infections tend to 

 disappear under ordinary treatment makes it at present extremely 

 difficult to estimate truly the therapeutic effects of vaccine 

 therapy. 



Wright holds that the opsonic qualities of the serum constitute the 

 means by which the body frees itself of the invading bacilli. A natural 

 cure results when the absorption into the circulation of the products of 

 the local disintegration of the tubercle bacilli so stimulates some reactive 

 mechanism in the body that sufficient opsonin is produced to cause a 

 phagocytosis of all the tubercle bacilli present. The occurrence of a low 

 opsonic index in chronic local tuberculosis is due to the using up of 

 the opsonins in the focus of infection, and in such a case the general 

 mechanism has not been stimulated to produce a conquering amount of 

 opsonin. The object of a vaccination is thus to supply this deficiency. 

 If it is successful, the focus is flooded with lymph rich in opsonin and the 

 bacilli are consequently phagocyted and destroyed. The reaction of the 

 opsonin-producing mechanism is, however, not a simple one, and as in 

 the introduction of other antigens, the injection of tuberculin is followed 

 by a period, normally lasting a day or two, when the amount of opsonin 

 is actually lower than it previously was (occurrence of negative phase). 

 This, in a successful vaccination, is followed by a rise in opsonic content 

 of the serum to a point above the level existent at the time of injection 

 (production of positive phase). In certain cases a positive phase is easily 

 obtained ; in other cases there is a tendency to a prolonged persistence of 

 the negative phase, and if during such an occurrence a fresh tuberculin 

 injection be produced, a still greater fall in opsonic content may occur, 

 usually accompanied b clinical exacerbation of the tubercular symptoms. 

 Immunisation is further complicated by the fact that there is a variable 

 and often uncontrollable absorption into the body from the focus of infec- 

 tion of what is really tuberculin derived from the disintegration of the 

 infecting bacilli. 



Antifrubercular Sera. — From what has been said regarding immunity 

 reactions in tuberculosis it will be gathered that it is questionable whether 

 the use of passive immunity in the treatment of tuberculosis has a rational 

 b&sis. Several investigators, however, have introduced the sera of animals 

 treated with the products of tubercle bacilli for therapeutic purposes. 

 Amongst these are Maragliano, who has treated dogs, asses, and horses 

 with materials derived from the tnbercle bacillus, and administers their 

 serum in doses of 2 c.c. every two days in human tuberculosis. An anti- 

 tubercular sera has also been introduced by Marmorek, who grows the 

 bacilli in media unfavourable to their vitality and employs such growths 



