THE FOCAL REACTION 79 



the other is a mistake that it should rather be the examination of 

 specificity and nonspecificity, i.e., that both factors enter into the 

 reaction and it should be determined how far each factor is involved." 

 Our concept has been that while the systemic reaction was largely 

 nonspecific in that the means used to elicit it need not be specific, the 

 focal reaction itself, once initiated, brings in its wake a truly specific 

 stimulation because the inflammatory reaction may lead to the libera- 

 tion of disintegrating bacterial material and possibly even living 

 bacteria. These substances would secondarily lead to a specific 

 response on the part of the body.* 



At least three factors must be considered in the mechanism of 

 the focal reaction in tuberculosis, apart from the anatomical pecu- 

 liarities of the tubercle as contrasted with other inflammatory proc- 

 esses. 



Specific. These concern primarily a tissue sensitization against 

 tuberculoprotein, strictly specific in character, cellular in its localiza- 

 tion and not necessarily associated with the older conception that was 

 built up about the humoral antibodies. Indeed I am of the opinion 

 that the latter may very well be relegated to a subordinate position 

 in the field of tuberculosis. Inasmuch as this subject of tissue sensi- 

 tization has been extensively discussed by a number of workers, par- 

 ticularly by Krause in this country, it will be unnecessary to enter 

 into this phase here. 



General Hyper sensitiveness of the Tuberculous. Granted that 

 the tuberculous focus responds to smaller doses of tuberculin than does 

 a focus of nontuberculous origin, how are we to account for the fact 

 in view of the* practical avascularity of the tubercle? That the speci- 

 ficity concept of the immunologist will no longer explain the accumu- 

 lated evidence is to-day acknowledged, and Wolff-Eisner accepts the 

 change in our viewpoint in a recent paper. I can but very briefly 

 enter into the more lengthy theoretical discussion that he presents. 

 He first emphasizes the relation that exists between the diet and 

 exudative diathesis,, defining this latter condition as due to the ab- 



* It is this factor that Klemperer in his recent criticism of Schmidt's claims 

 has ignored. Klemperer found that following milk injections in tuberculous 

 patients they did not become resistant to following injections of tuberculin and 

 vice versa. Injections of milk bring about a febrile reaction in a large per- 

 centage of individuals; they bring about a focal reaction in only a limited 

 number of tuberculous patients, just as tuberculin injections are followed by 

 focal reactions in an irregular number. If the injection of milk brings about 

 (in the tuberculous individual) a systemic reaction without focal activation, a 

 following injection of tuberculin may still give rise to a typical general reaction. 

 If, on the other hand, a focal reaction results, either by specific or nonspecific 

 means, local tuberculin reactions are suppressed for some time following the 

 general reaction. Klemperer is, however, quite justified both in his criticism of 

 the local reactions reported by Schmidt following milk injections in tuberculous 

 patients and in his views concerning the possible harm from activation of tuber- 

 culous foci following milk injections. 



