I030 TUBERCULIN AND THE TUBERCULIN REACTION 



bacillus was rushed into publishing a premature announcement of the curative virtue 

 of a substance which immediately received almost hysterical reception under the name 

 "Koch's lymph." In the profound disappointment which followed its failure to 

 achieve the cures expected and its actual injury of large numbers of patients, tubercu- 

 lin was for a time given up and even banned as a poison. 



However, in the succeeding years cautious retrials established to the satisfaction 

 of the majority of physicians that, while falling far short of original expectations, 

 tuberculin was of distinct value in cases of tuberculosis of a certain variety. It is 

 usually accepted today that localized tuberculosis of chronic, obstinate type, slug- 

 gishly progressive, as seen in bones, lymph nodes, and skin, may be stimulated to 

 scarification and fibrous investment by the proper use of tuberculin. Many ophthal- 

 mologists consider it the best treatment for eye tuberculosis. 



The technique of its usage is outside the scope of this chapter, and may be read in 

 the standard texts. A rational basis for its administration, which is all that can be 

 touched here, is known today. In the time of Koch the observation leading to its 

 introduction as a cure was empiric. Tuberculin, without effect on the uninfected ani- 

 mal, causes local, focal, and general reactions in the patient with tuberculosis. The 

 local reaction at the site of injection is probably without significance in treatment, 

 except as an index of the patient's sensitiveness. The focal reaction occurring at the 

 site of disease, on the other hand, is of the utmost importance. Mild focal reactions 

 are beneficial, and severe ones detrimental. Marked focal reactions lead to general 

 reactions, presumably from undue absorption of the degenerated tissue at the focus, 

 as Krause' points out, an event leading to toxemia, fever, loss of weight, and general 

 harm to the patient. 



The probable explanation for the focal reaction is exceptional sensitiveness of the 

 cells in the immediate region of tuberculous tissue, surpassing that of all other tissues 

 of the generally sensitized body. Minute amounts of tuberculin, too small to stimu- 

 late response from the remote tissues, cause inflammation around tubercles, and if 

 kept within bounds promote walling in of the lesion by phagocytic cells and fibrous 

 tissue. 



This condition is illustrated in Figures 4 and 5, showing pulmonary tubercles in 

 tuberculous guinea pigs, one of which received a large dose of tuberculin, the other 

 not being treated. In the non-treated animal all tubercles were in the condition shown 

 in Figure 4, discrete, sharply marked off from the surrounding lung tissue. The tuber- 

 cle shown in Figure 5, on the other hand, is poorly defined, the cells of an exudative 

 reaction appearing in the surrounding alveoli. This animal, a mate to the one shown 

 in Figure 4, was killed the day after administration of a heavy dose of tuberculin. 



If tuberculin has this effect on artificial administration, it is reasonable to suppose 

 that tuberculin suddenly eliminated into the system from the flaring up of one focus 

 of disease due to any cause might result in a focal reaction around tuberculous regions 

 elsewhere. F. M. Pottenger has shown me Rontgen ray plates indicating that this 

 occurs, and believes such spontaneous tuberculin reactions are important in the 

 natural cure of tuberculosis. 



' Krausc, A. K.: New York Med. J., April 19, 1922. 



