1973 Volume 22 Issue 7 Pages 486-493,502
Bronchial sensitivity to acetylcholine was measured on subjects selected from three groups, i.e. Group A: asthmatic subjects whose asthma had ceased three years or more before testing, Group B: asthmatic subjects having asthma attack currently, Group C: non-atopic normal subjects. Sensitivity of bronchi to inhaled acetylcholine was quantitatively presented as the "respiratory threshold for acetylcholine": the minimal amount of the inhaled agent which causes the initial decrease of FEV_<1.0> greater than 10 per cent from standard. IgE concentration and IgE antibody titer to mite allergen in the sera of the subjects were also determined. Following results were obtained: 1. IgE antibody titers to mite allergen were clearly elevated in Group A or in Group B as compared with low titer in Group C (p<0.01), but no difference was found statistically between Group A and Group B. 2. Serum IgE concentration ranged 10-2250 unit/ml in Group A, 10-3400 unit/ml in Group B and 10-600 unit/ml in Group C, respectively. 3. Twelve (60 per cent) from 20 cases of Group A showed low bronchial responsiveness to inhaled acetylcholine and four cases responding intensely to the agent, whereas Group B contained a large proportion who reacted moderately or markedly. Three of four cases in Group A who responded intensely to acetylcholine revealed the low concentration of IgE. No significant correlation between the respiratory threshold for acetylcholine and IgE concentration of sera was obtained. These findings suggest that the bronchial sensitivity is important factor for asthmatic attack, though serum concentration of IgE might be another important factor.
