ISOHEMOLYSINS 393 



found the serums of cancer, pneumonia, and Addison's disease to be 

 actively hemolytic for normal corpuscles. Weil, Crile, Blumgarten 

 and Whittemore, and others have found a large proportion of the serums 

 of lower animals and man suffering with malignant tumors to possess 

 hemolytic activity for normal erythrocytes, and that a reaction based 

 upon this property may have diagnostic value. While isohemolysins 

 are to be especially found in the serums of cancerous persons, and the 

 corpuscles of tuberculous persons are hypersensitive and readily hemo- 

 lyzed, reactions based upon-these observations are not specific, although 

 they may have some diagnostic value in relation to other symptoms. 

 It is well to remember this property of cancer serum, especially in making 

 blood transfusions. 



The results of many isohemolytic tests with human sera and cor- 

 puscles by different investigators have shown that human isohemoh^sins 

 may be present, and that they have a practical importance in relation 

 to the dangers of blood transfusion. The consensus of opinion is to the 

 effect, however, that hemagglutinins are of more importance in this 

 connection. The technic of these tests is given on page 311. 



Production of Immune Hemolysins. Hemolysins are readily pro- 

 duced by injecting suitable animals with several doses of red blood- 

 corpuscles. For this purpose rabbits are commonly employed. Some 

 hemolysins are more readily produced than others; for example, anti- 

 sheep hemolysin is easily prepared, whereas it is far more difficult to 

 secure a potent antihuman hemolysin. The various methods employed 

 in preparing hemolytic serums have been described in the chapter on 

 Active Immunization of Animals. Antisheep hemolysin for conducting 

 the Wassermann reaction is readily prepared by giving a rabbit three or 

 four intravenous injections of 5 c.c. of a 10 per cent, suspension of washed 

 sheep's cells in sterile normal salt solution at intervals of three days. 

 The blood-cells should always be washed three or four times with an 

 excess of salt solution to remove all traces of serum, in order that pre- 

 cipitins may not be produced and anaphylactic shock of the inoculated 

 animal avoided. 



The portion of the erythrocyte that is responsible for the production 

 of hemolysins is a moot question. Bordet and von Dungern maintain 

 that the stroma is the exciting agent; Nolf and others believe that the 

 stromata produce hemagglutinins, and that the hemoglobin is chiefly 

 concerned in the production of the hemolysin. 



General Properties of Hemolysins. Hemolysins are highly resistant 

 antibodies, and are easily preserved. Sterile immune serum may be 

 inactivated by heating in a water-bath for half an hour at 56 C., and 



