Atopy and bronchial reactivity in older patients with cystic fibrosis

Abstract

We studied 25 adolescent and adult patients with cystic fibrosis (CF) and 25 control subjects to determine if the prevalence of atopy and bronchial hyperreactivity was increased in this disease. Results showed that atopic symptoms, as defined by history, were more frequently present in the CF patients. Prick testing of the skin produced positive reactions in 88 % of the CF group and 360% of the control subjects (p <0 001), and the mean number of reactions per subject was significantly higher in the former group (p < 0 001); reactions to fungal antigens were strikingly positive in the CF group. The CF patients had a significantly higher mean serum IgG4 (p <000 1), IgE (p <00 1), and higher mean eosinophil count (p > 0 05). Clear-cut bronchial hyperreactivity was demonstrated in the CF group compared with control subjects. Bronchial provocation with 400 jig of histamine led to a greater than 15 % fall in the preinhalation FEV, in 35 % of the CF subjects compared with 40% of the control group, with a mean percentage fall of 15 % and 3 % respectively (p < 0 00 1). In the CF group a greater than 15 % rise in PEFR occurred in 32 % after inhalation of the parasympatholytic, ipratropium bromide (54 jig), and in 270% after inhalation of the sympathomimetic, fenoterol (400 pg). No correlation was found between bronchial reactivity and atopic status, HLA phenotype pattern, or disease severity. The cause of the increased prevalence of atopy and bronchial reactivity in CF patients remains unknown. However, it is clear that a trial of bronchodilator therapy is warranted in adolescents and young adults with CF.