102 



Scientific Proceedings (74). 



form of diphtheria antitoxin, antimeningococcus serum or anti- 

 pneumococcus serum, intravenously, intraspinally or intramuscu- 

 larly. Nine of the eleven cases developed serum sickness. 



All of the cases, whether or not they developed serum disease, 

 showed sooner or later a positive specific reaction to the intracu- 

 taneous injection of horse serum. This was never obtained before 

 the seventh day following the first therapeutic injection of horse 

 serum and was first observed between this day and the eighteenth. 

 It was never demonstrable until after the appearance of serum 

 disease. 



Anaphylactic antibodies could not be demonstrated in the two 

 cases that did not develop serum disease. In all of the other nine 

 cases these antibodies were found at some time in the serum of the 

 patient. In but one case did they appear before the onset of 

 serum disease and then on the fifth day after the therapeutic 

 injection of horse serum. Neither in this instance nor in any 

 other was the anaphylactic antibody demonstrable in the patient's 

 serum during the early part of serum sickness. In all nine cases 

 the anaphylactic antibody was present in maximum concentration 

 at the close of the serum sickness and in one instance persisted for 

 sixty-eight days after the disease. In two cases in which the 

 original attack of serum sickness was followed by a relapse, the 

 antibodies could not be definitely demonstrated until the end of 

 the relapse, that is twenty-one and twenty-four days after the 

 therapeutic injection of horse serum. In several instances it was 

 possible to sensitize guinea-pigs both passively and actively to 

 horse serum with portions of the same specimen of blood serum 

 drawn from the patients towards the close of the serum sickness, 

 thus demonstrating that some of the proteins of horse serum and 

 antibodies for the proteins of horse serum may exist at the same 

 time in the circulation in man. 



These experiments show that anaphylactic antibodies for horse 

 serum appear in maximum concentration in the blood serum 

 towards the close of serum sickness and suggest that their presence 

 in the circulation in large amounts determines the recovery from 

 this disease. 



