ARTHUR F. COCA loii 



the date of onset of symptoms, it seems necessary to conclude that some persons are 

 destined, by inheritance only, to become sensitive to a certain substance on about a 

 certain date. 



It seems reasonable to suppose that the actual state of hypersensitiveness de- 

 velops only after sufficient contact with the excitant; of course, the exhibition of 

 symptoms is dependent upon such contact. 



ANAPHYLACTIC ANTIBODIES IN HUMAN BEINGS 



The similarity between anaphylactic and atopic hypersensitiveness has naturally 

 led many writers to look upon these conditions as identical. The chief similarity be- 

 tween these two forms is the existence of the specific mechanism in both, and the 

 identification of the two on this ground could be considered reasonable if reagins were 

 the only specific sensitizing bodies produced by the human being. However, it is 

 known, especially through the valuable researches of Anderson and Schloss,' that ana- 

 phylactic antibodies also are produced by normal human beings, precipitating anti- 

 bodies having been previously demonstrated in human beings by numerous investi- 

 gators. 



The human being actually is capable of producing the anaphylactic mechanism; 

 yet this mechanism has not been shown to be capable of mediating any physiological 

 reaction in the human being, although it is of course able to sensitize the guinea pig. 

 The normal babies in whose blood Schloss and his co-workers could demonstrate ana- 

 phylactic antibodies were not themselves hypersensitive to the respective foreign 

 proteins (milk or egg). Anaphylactic antibodies can sometimes be found in the blood 

 of human beings subject to serum disease. This association is, however, too irregular 

 to permit one to consider the etiological relationship proved, 



DANGERS ATTENDING THE INJECTION OF FOREIGN SERUM 



The demonstration of the strict hereditary control of atopic hypersensitiveness 

 carried with it the corollary that, in persons not subject to the atopic hereditary in- 

 fluence, atopy cannot be induced. This conclusion is of course important in connec- 

 tion with the question of the reinjection of a foreign protein such as horse serum. 

 Atopic hypersensitiveness (hay fever or asthma) cannot be induced in a normal hu- 

 man being by injection of horse serum. However, the reinjection of horse serum after 

 the incubation period of serum disease is sometimes followed by an accelerated or im- 

 mediate reaction of serum disease, which is so severe that it may even endanger life 

 or actually end it. It seems, in some instances of this kind, that the intravenous re- 

 injection is more dangerous than the subcutaneous or intramuscular, although, even 

 after subcutaneous reinjection, symptoms may rarely develop within two or three 

 minutes. 



It will be useful to formulate, out of our knowledge of the dangers attending the 

 injection of foreign sera, a reasonable attitude in which the exigencies of the condition 

 requiring serum treatment are weighed properly against the probable risk of serious 

 reaction. 



Experience with the injection of the various excitants into atopic persons indicates 

 that the greatest tolerance induced by this means is usually reached only after a pe- 



' Anderson, A. F., and Schloss, O. M.: /. Dh. Child., 26, 451. 1Q23. 



