SIGNIFICANCE OF ALLERGY 547 



2. That the most important factors in the type of immunity 

 (partial, i.e., not absolute) to the tubercle bacillus resulting 

 from vaccination or infection are mononuclear phagocytes 

 and humoral elements. 



3. That in the tuberculin allergic inflanunation in the guinea 

 pig a more efficient mechanical barrier favoring localization 

 is laid down than in the hypersensitive rabbit. 



4. That within limits the degree of injury to the tissues in an 

 area of allergic inflammation may affect the amount of local 

 fixation of the infectious agent. Too large a dose of the 

 bacteria may lead to a breakdown in the local mechanism of 

 fixation and permit a more rapid spread to the regional lymph 

 nodes in an allergic animal than in a normal one. 



5. Allergic inflanimation unsupported by specific immunity fac- 

 tors fails to prevent the escape of bacteria from the area 

 of allergic inflammation. 



It would seem from the above discussion that many of the ap- 

 parent contradictory conclusions can be, in a measure, recon- 

 ciled. In this connection a few other observations may be of in- 

 terest. Teale (1935) is of tlie opinion that " hypersensitiveness 

 is due to the state of tlie tissues which cannot deal with the specific 

 antigen even when it is completely saturated with the homologous 

 antibody." Woodruff and Willis (1939) conclude that there is a 

 partial reciprocal relationship between the allergic state of in- 

 fected guinea pigs and the number of bacteria found in the 

 lungs. Corper (1940) has attempted to compare tuberculin al- 

 lergy due to infection with anaphylactic hypersensitiveness to 

 tubercle proteins. Apparently further work is indicated before 

 it can be evaluated. 



Effect of Primary Lesion in Children Upon Subsequent Infec- 

 tion. — At the present time there is considerable discussion as to 

 the effect of initial or primary infection on subsequent tuber- 

 culous lesions in man. It is quite generally held that primary 

 infection with the tubercle bacillus immunizes the individual and 

 in part at least protects against later infections from exogenous 

 sources. Myers and Harrington (1934) conclude from their study 

 of a very large number of children that five times as many of 

 those with initial positive tuberculin tests fall ill in later years 

 with tuberculosis as do those who on first examination give 



