IMMUNITY 



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known as idiosyncrasy, it has been assumed by some that anaphylaxis, allergy 

 and idiosyncrasy are essentially the same. This may or may not be true. 



There are two apparent differences between idiosyncrasy and allergy or 

 anaphylaxis: idiosyncrasy is a hypersensitiveness disclosed by a primary dose 

 of the irritant; this hypersensitiveness persists after recovery from one or more 

 doses that precipitate symptoms of intoxication. 



Those who hold the opinion that anaphylaxis, allergy and idiosyncrasy are 

 basically the same, look upon luetin, mallein, typhoidin and tuberculin reactions 

 as anaphylactic manifestations. Until more is known it is unsafe to generalize. 



Sensitization to tuberculin may be general or localized. An animal afflicted 

 with active tuberculosis causing general toxemia shows a generalized hypersen- 

 sitiveness to tuberculin; should the disease become dormant, hypersensitive- 

 ness may continue at the same degree as when the disease was active or it may 

 be reduced; or, general sensitization may decline, but certain organs or tissues, 

 as the skin and conjunctiva, continue equally as sensitive in the dormant state 

 of the disease as they were in the active state. 



Local sensitization to tuberculin without generalized sensitization can be 

 produced in non-tuberculous animals. The instillation of tuberculin will 

 sensitize the conjunctiva of a healthy rabbit's or man's eye so that a second 

 instillation causes a violent local reaction, while a primary instillation in the 

 opposite eye, at the tune of the second instillation in the sensitized eye, pro- 

 duces no reaction. 



The recent investigations of Manwaring and Kusama show that in some 

 instances, at least, a dose of antigen administered to a sensitized animal im- 

 mediately acts on the lungs in a manner that greatly impairs or totally prevents 

 respiration and aeration of the blood. While such pathological changes account 

 for the respiratory distress commonly observed in anaphylactic attacks and 

 could be responsible for sudden death, they do not explain the paralysis. Other 

 investigators have shown involvement of other vital organs, especially the 

 kidneys. 



By perfusing the lung of a normal non-sensitized animal, with a mixture 

 of blood serum and antigen from a sensitized animal, the same pathological 

 changes are produced as occur in a sensitized animal following a dose of antigen. 



Manwaring and Kusama state that the serum of a guinea-pig immune to 

 horse serum, when mixed with horse serum makes it inert just as diphtheria 

 antitoxin neutralizes diphtheria toxin, so that the injection of a mixture of 

 immune guinea-pig serum and horse serum into a sensitized guinea-pig does not 

 produce any manifestation of anaphylaxis. They also report that a guinea-pig 

 immunized to horse serum enjoys immunity by virtue of substances in its blood 

 serum which act on horse serum and neutralize it before it reaches fixed tissue 

 cells. The fixed tissue cells of such immune animals are hypersensitive to 

 horse serum; this being shown by freezing the lungs of an immune guinea-pig 

 of their native blood and perfusing them with a mixture of normal guinea- 

 pig serum and horse serum, the p'erfusion causing a typical anaphylactic 

 manifestation. 



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