532 IMMUNOLOGY 



that transplants of bone marrow and spleen from tuberculous 

 animals are killed by dilutions of tuberculin that have no effect up- 

 on similar culturas from normal animals. Furthermore Dorset, 

 Henley and Moskey (1927) obtained a fraction of tuberculin which 

 produces severe and fatal systemic reactions in tuberculous guinea 

 pigs but is inert when administered intracutaneously. In the 

 systemic reaction the tissues immediately adjacent to the lesions 

 give the greatest allergic response. 



Studies of Corper and Cohn. — These authors compare tuberculo- 

 anaphylaxis and tul)erculo-allergy. The former was produced by 

 injection of tubercle protein wliile the latter was produced by 

 infection. The differences they found between the two are: 



1. Tuberculo-anaphylaxis symptoms could be elicited only when 

 the shocking dose was given intravenously, whereas tuberculo- 

 allergic intoxication could be induced by intravenous, subcuta- 

 neous, or intraperitoneal injections. 



2. The symptoms of tuberculo-anaphylaxis were the typical 

 ones of all protein anaphylaxis, whereas in tuberculo-allergic in- 

 toxication the symptoms were slow to develop, coming on in from 

 a few hours to seventy-two hours, and did not resemble those of 

 anaphylaxis. 



Corper and Cohn also report that histaminase had no retarding 

 or neutralizing effect on either tuberculo-anaphylaxis or tuberculo- 

 allergy. 



From the preceding discussion of tuberculin and other bacterial 

 allergies, the following general conclusions can be drawn : 



1. That tuberculin allergy develops from infection or vaccina- 

 tion with the tubercle bacillus or with an antigenic tuberculin. 



2. The allergic state apparently results from the effect upon 

 the tissues of some diffusible substance formed within a tubercle, 

 presumably by the action of certain cellular enzymes within the 

 lesion, upon the tubercle bacilli present. 



3. The safest method of detecting tuberculin allergy is by the 

 intracutaneous administration of small doses of tuberculin. It has 

 been demonstrated that relatively large doses may give nonspecific 

 reactions. 



4. Allergy does not persist long after recovery. 



