AGGLUTININS AND PRECIPITINS 105 



Reactions to Transfusion. The effects on the body of introducing 

 high titer hemagglutinins have been studied experimentally in normal 

 animals and in those which have been splenectomized. In normal animals 

 there is found agglutination of red blood-corpuscles with embolism in 

 liver, lungs and other viscera. The liver is often found to show hyaline 

 necrosis in connection with the emboli. The spleen is large and dif- 

 fluent, and there are small areas of necrosis as well as phagocytosis of 

 erythrocytes by endothelial cells. Necrosis is also found in the fol- 

 licles of lymph-nodes. Multiple hemorrhages may also be noted. After 

 splenectomy the phagocytic function of the spleen is taken over by the 

 lymph-nodes. The incident hemolysis in either case leads to hemo- 

 globinemia and hemoglobinuria, but in splenectomized animals the 

 threshold of excretion of hemoglobin is somewhat higher than in 

 normal animals. 



In severe and fatal reactions in man the phenomena are not likely 

 to be so marked. Phagocytosis of erythrocytes by the recipient's leuco- 

 cytes has been observed. We have performed autopsies on twelve 

 cases in which transfusion was practised shortly before death, in three 

 of which the death was at least in part due to the use of unsuitable 

 blood. In all of these the spleen was considerably enlarged (170, 

 390, 400 grams), and in one there were multiple small hemorrhagic 

 infarcts. One case showed enlarged soft white lymph-nodes. The 

 bone marrow was normal in all. All showed marked cloudy swelling 

 of the kidneys. Two showed hemoglobinuria, and in one of these 

 there was post-mortem staining by hemoglobin. In the case with 

 multiple infarcts of the spleen 50 c.c. Group II blood had been given 

 to a Group III recipient, and there was neither hemoglobinemia nor 

 hemoglobinuria. In the case with hemoglobinemia and hemoglobin- 

 uria about 700 c.c. Group III blood was given a Group I recipient. 

 Unfortunate accidents led to these errors, and the groups were dis- 

 covered subsequent to the operations. In the nine cases where the 

 transfusions were satisfactory the spleen was either normal or if 

 enlarged was accompanied by septicemia. 



Chemical Agglutination of Erythrocytes. Blood-corpuscles are 

 agglutinated not only by various sera but also by certain chemical sub- 

 stances. Gay has examined the function of the tonicity of the sur- 

 rounding medium in determining iso-hemagglutination and maintains 

 that the bloods of that group whose cells are non-agglutinable (Group 

 I) are constantly of higher total molecular concentration than the 

 other bloods. He further states that a " simple hypertonic solution 

 of CaCl 2 , but more particularly solutions hypertonic both in respect to 

 NaCl and CaCl 2 , produces a cohesion of any human blood after sev- 

 eral hours resembling iso-agglutination." Studies of hypotonic solu- 

 tions and of variations of any considerable degree in hydrogen ion 

 concentration have been rendered difficult because hemolysis is likely 

 to occur under these conditions and render conclusions difficult. Land- 

 steiner and Jagic in 1904 were the first to call attention to the fact that 

 a well-defined colloid, namely silicic acid, agglutinates erythrocytes. 



