Objective: In patients with cystic fibrosis, bronchial hyperreactivity is a common finding that has not been conclusively associated with atopy. The objective of the present study was to determine the relationship between chronic colonization or infection with Pseudomonas aeruginosa and bronchial hyperreactivity in a group of patients with cystic fibrosis.
Patients and methods: A nonspecific histamine bronchial provocation test was administered to a group of 32 cystic fibrosis patients with a mean (SD) age of 11.25 (3.7) years. The presence of atopy and of chronic colonization or infection with P aeruginosa was also studied.
Results: Nine of the 32 patients (28.1%) studied showed bronchial hyperreactivity. The clinical status of these 9 patients was significantly worse and all were colonized or infected with P aeruginosa. Atopy was present in 17 of the 32 patients (53.1%) in the study group, but in only 3 of the 9 patients (33.3%) with bronchial hyperreactivity. Bronchial hyperreactivity was significantly associated with colonization or infection with P aeruginosa (P< .001), but not with atopy (P=.12). In the patients without atopy, colonization was significantly associated with bronchial hyperreactivity (P=.017). In the group with normal lung function (forced expiratory volume in 1 second >/=80%) this association was also significant (P=.044), while the association between bronchial hyperreactivity and atopy was not (P=.11).
Conclusions: The results of the present study suggest that in patients with cystic fibrosis, bronchial hyperreactivity may be associated with colonization or infection with P aeruginosa, and that this may be a more important risk factor for bronchial hyperreactivity than atopy.