Aerosolized antigen dose-response studies in asthmatic monkeys.

This study used rhesus monkeys which had consistent respiratory responses to a standard (single dose) aerosolized concentration of A. Beginning at lower concentrations of A which did not produce an airway response, fourfold increases in concentrations of A were aerosolized until an airway response occurred. Compared with the single-dose SAC after the TAC, some consistently reactive animals did not respond to the SAC, the maximal concentration of A used for testing. Thus the TAC may result in an acute form of airway desensitization. Animals vary in the threshold concentrations of A required to produce an airway response. A repeat challenge with the threshold antigen concentration during the same experiment resulted in a second response generally greater than the initial response at the same concentration. When the SAC system was similarly evaluated by repeat challenges with the same A concentration, the second response was generally less than the first. Different methods for evaluation of pharmacologic inhibitors of IgE-mediated airway responses may be developed from this rhesus model of asthma.