Comparative histologic and immunologic studies in rabbits of induced hypersensitivity of the serum sickness type. II. The effect of sensitization to homologous and cross-reactive antigens on the rate of antigen elimination and the development of allergic lesions.

Sensitization of rabbits with bovine albumin and the cross-reactive antigen, egg albumin, increased the rate of bovine albumin elimination following its intravenous administration. Elimination of this antigen was complete in 7 and 10 days respectively instead of approximately 2 weeks as in unsensitized normal animals. The peak incidence of allergic tissue alteration was proportionately accelerated. Certain qualitative and quantitative differences between the histologic responses of the sensitized and unsensitized rabbits were noted. These differences were probably due to the shorter period of antigen-antibody interaction in the sensitized animals in which the antigen was quickly eliminated. The temporal relationship between the histologic and immunologic responses in sensitized animals adds further support to the hypothesis that the lesions which occur after the injection of foreign protein are the result of antigen-antibody combination.