Q2 IMMUNITY 



determined that persons giving a negative reaction need not receive immuniz- 

 ing doses of anti-toxin. About 80 percent of adults and 30 to 40 percent 

 of children are immune. A negative reaction seems to indicate that the blood 

 contains Ko c.c. more unit of anti-toxin per cubic centimeter. 



Isoagglutinin and Isohemolysin 



There are frequently in the blood of animals, ly tic and agglutina- 

 tive anti-bodies for the red cells of other members of the same 

 species. By this is meant that if the blood of a man be mixed with 

 that of another the cells of one of them may be clumped or dis- 

 solved. This is of considerable importance to the surgeon who 

 wishes to transfuse blood, for were he to use a donor whose blood 

 was unlike that of the recipient the latter would have a serious 

 chill, indications of blood destruction and shock, and he might die. 



These two substances are probably independent in action but 

 are so commonly found acting in harmony that they may be con- 

 sidered inter-dependent. Landsteiner and Jansky divided persons 

 into four groups according to their agglutinin and agglutinogen. 

 Moss made the same observation but classified them differently. 



JANSKY'S GROUPING 



Serum 

 Cells I II III IV Percent 



I 42.84 



II + + 10.36 

 HI + + 41-38 

 IV + + + 5-42 



This means that the cells of Type I are not agglutinated by an] 

 of the serums, whereas the cells of Type IV are clumped by 

 serums but their own. 



Agglutination is accomplished according to Landsteiner by tw< 

 agglutinins a and b which are both contained in serums clumping 

 all type of corpuscles, whereas both are absent in serums clumpii 

 no cells. Agglutinable bodies, represented by a and b, are suppos 

 to be present in the respective cells which can be clumped, absent 

 in the others. Group I therefore contains agglutinins A and B 

 but does not contain agglutinable bodies a and b. Other groups 



