Paroxysmal Hemoglobinuria 



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in chilling the patient's blood to 0° C. for 30 minutes, and then 

 warming it to 37° C. In normal blood no hemolysis occurs 

 after the blood has been warmed to 37°. More consistent re- 

 sults are obtained by using serum and a suspension of washed 

 red cells, and by adding complement. This auto-hemolysin has 

 been the subject of a number of studies which need not here 

 be reviewed. The reaction has been shown to be an antigen- 

 amboceptor-complement reaction with the characteristic that the 

 hemolysin unites with the red cells only at a low temperature. 

 It has also been shown that the combination of corpuscles and 

 hemolysin occurring at low temperatures is at least partially 

 broken up at higher temperatures, and that an iso-hemolysin 

 demonstrated by chilling, as well as the auto-hemolysin, is pres- 

 ent. 



During the past three years we have had an opportunity to 

 study the blood of three patients who are subject during the 

 winter months to typical attacks of hemoglobinuria. Unless 

 otherwise stated, the Landsteiner reaction has been done in our 

 work by using 0.25 c.c. of serum, and 0.1 c.c. of a 5 per cent, 

 suspension of washed red blood cells, and adding as complement 

 0.1 c.c. of pooled guinea pig serum diluted 1 : 10. The volume 

 is made up to 0.5 c.c. with normal salt solution, and the tubes 

 are then kept at 0° C. for 10 minutes, and in the water bath at 

 37° for 2 hours, when readings are made. Control serums and 

 red cell suspensions were always from the same blood group. 



In contrast with most sensitizing antibodies, this auto-hemo- 

 lysin may show marked thermolability. In one of our cases 

 45° C. for 30 minutes destroyed the hemolysin so that it could 

 not be reactivated by addition of fresh complement. The tem- 

 peratures required to destroy the hemolysin in the other two 

 cases were 47.5° C. and 55° C. 



The demonstration of the presence of the auto-hemolysin is 

 usually accomplished by chilling the serum-erythrocyte-comple- 

 ment mixture to 0° C, but obviously such a low temperature is 

 not present at the site of the in vivo reaction. It seemed worth 

 while, therefore, to determine the highest temperature at which 

 the union of hemolysin and erythrocyte occurs. Two of the 

 hemolysins sensitized at temperatures from 0° C. to 12° C. ; 

 the third did not sensitize above 8° C. It seems quite possible 

 that the blood in the superficial capillaries may, in cold weather, 



