Distribution of XXXX inhalation challenge responses in a selected adult population.

@entity1 @entity565 @entity281 @entity56 @entity2710
To determine bronchial reactivity patterns in adults, 211 subjects, 22 to 86 years of age, underwent a @entity2710 challenge in a Natural History of Asthma study. The diagnosis of @entity565 or nonasthmatic @entity56 was based on a standardized respiratory questionnaire. Subjects were nonsmokers and had not had an @entity281 for 1 month. Intradermal skin tests were done to a battery of common antigens. The @entity2710 challenge response was expressed as the area under the dose-response curve integrated to a 35% fall in the FEV1 or 800 breath units. Thirty-three subjects with @entity565 , 47 normal subjects from normal families (NF), 59 normal subjects from families with @entity565 (AF), 31 allergic subjects without @entity565 , 23 subjects with questionable @entity565 , and 18 subjects with prior @entity565 were studied. Overall, 50% of the subjects without @entity565 had a negative response to @entity2710 . There was a difference (p less than 0.02) in the distribution of log10 @entity2710 area under the dose-response curve integrated to a 35% fall in the FEV1 or 800 breath units responses in normal subjects from NFs compared to normal subjects from AFs. The allergic subjects from AF had a greater degree of bronchial reactivity compared to normal individuals from NF. The age of the normal subjects had an influence on the degree of bronchial reactivity. @entity2710 challenge studies in adult @entity1 need to be interpreted with age and family history in mind.
