BLOOD AND BLOOD DERIVATIVES — COHN 431 



Despite the presence of these isoagglutinins in serum or plasma 

 individuals of all blood groups may be transfused with a pooled serum 

 or plasma. The plasma is rendered safe partly by neutralization 

 within the pool. The specific A and B substances have recently been 

 injected in more or less pure state and shown to increase the titer of 

 the recipient's plasma isoagglutinins. 



The isoagglutinins of the plasma are euglobulins which are ex- 

 tremely insoluble in the absence of salt near their isoelectric points. 

 Readily separated and concentrated over thirtyfold with respect to the 

 group-specific serum or plasma from which they are derived, they can 

 be used in the typing of whole blood. Indeed they may be prepared 

 with such high titers and avidity for red cells of the opposite type that 

 gross clumping observable to the naked eye is brought about in a matter 

 of seconds. The blood-grouping globulins are also being prepared 

 from Fraction 11 + III of group-specific plasma derived from the 

 blood of Red Cross donors and are beginning to be used by the Navy 

 for typing when whole-blood transfusion is indicated. 



THE IMMUNE PROPERTIES OF THE yGLOBULIN ANTIBODIES OF 

 NORMAL AND CONVALESCENT PLASMA 



Many of the antibodies to the variety of infectious diseases to which 

 man has been exposed are y-globulins. These substances have in the 

 last few years been concentrated and extensively studied not only chem- 

 ically but also immunologically. The antibodies to many of the 

 common infectious agents to which the population contributing the 

 blood had been exposed have been found. Indeed the large number 

 of blood donors in the Red Cross blood-donor program has made statis- 

 tical deduction valid and demonstrated that a population shows 

 heightened immunity following an epidemic of a special disease, such 

 as the recent influenza epidemic. 



The possibility of utilizing the y-globulin antibodies derived from 

 pooled normal plasma in the prophylaxis and therapy of any infectious 

 disease depends upon two factors : first, the concentration of specific 

 antibody in the blood of the adult population, which in turn is depend- 

 ent on previous exposures and on the persistence of these bearers of 

 immunity in the body and their distribution between blood and tissues ; 

 and second, the amount of antibody necessary to protect an individual 

 against the infection by passive immunization. 



The concentration over the pooled plasma thus far achieved by our 

 fractionation process is approximately twenty-five-fold if we compare 

 plasma with the concentrated solution of immune globulins being made 

 available to the Armed Forces, and through the Red Cross, to public 

 health agencies. As a result titers of certain antibodies, though not 

 necessarily of all, are comparable to those of the corresponding con- 



