Development of immune reactions in serum disease

The occurrence of immune reactions to horse serum and their relationship to the development of serum disease in man, we have studied by two methods: first, the sensitiveness of the skin to intravenous injections of 0.02 c.c. of horse serum, undiluted or diluted ten times or one hundred times with 0.85 per cent. NaCl; and secondly, by determining the presence of anaphylactic antibody in the blood serum of the patient by transference to guineapigs through passive sensitization.

Eleven patients have been studied, who have received for therapeutic purposes from 4 c.c. to 350 c.c. of horse serum, in the form of diphtheria antitoxin, antimeningococcus serum or anti-pneumococcus serum, intravenously, intraspinally or intramuscularly. 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 intracutaneous 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.