Comparison of the Histopathology of Immediate and Late Asthmatic and Cutaneous Responses in a Rabbit Model

Abstract

The histopathologic changes in the skin and lung in the immunized rabbits are summarized in Table 1. At 30 minutes, cutaneous reaction sites and the submucosa of large airways displayed interstitial edema and vessel dilatation, while the small airways remained uninvolved. At 6 hours, both cutaneous reaction sites and the submucosa of large airways showed a moderate perivascular and interstitial cellular infiltrate with residual edema. In addition, the bronchiolar walls showed an intense, widespread mixed cellular infiltration. Similarly, there was widening of the vessel adventitia due to lymphatic dilatation and leukocyte infiltration. At 48 hours, while the edema had cleared, there was an increase in the mixed cellular infiltrate about both pulmonary and skin vessels and large and small airways. These observations showed that immunized rabbits challenged with antigen develop cutaneous and pulmonary inflammation. In conclusion, the immediate and late cutaneous responses in the rabbit model are similar to those described in the human skin. In this rabbit model, pulmonary changes are similar to those found in the skin. Thus, the pulmonary pathology in the rabbit model may be similar to the pathologic events that occur in allergic humans who have immediate and late asthmatic responses following an encounter with an antigen.