Risk factors for bronchiectasis in children with cystic fibrosis.

BACKGROUND Bronchiectasis develops early in the course of cystic fibrosis, being detectable in infants as young as 10 weeks of age, and is persistent and progressive. We sought to determine risk factors for the onset of bronchiectasis, using data collected by the Australian Respiratory Early Surveillance Team for Cystic Fibrosis (AREST CF) intensive surveillance program. METHODS We examined data from 127 consecutive infants who received a diagnosis of cystic fibrosis after newborn screening. Chest computed tomography (CT) and bronchoalveolar lavage (BAL) were performed, while the children were in stable clinical condition, at 3 months and 1, 2, and 3 years of age. Longitudinal data were used to determine risk factors associated with the detection of bronchiectasis from 3 months to 3 years of age. RESULTS The point prevalence of bronchiectasis at each visit increased from 29.3% at 3 months of age to 61.5% at 3 years of age. In multivariate analyses, risk factors for bronchiectasis were presentation with meconium ileus (odds ratio, 3.17; 95% confidence interval [CI], 1.51 to 6.66; P=0.002), respiratory symptoms at the time of CT and BAL (odds ratio, 2.27; 95% CI, 1.24 to 4.14; P=0.008), free neutrophil elastase activity in BAL fluid (odds ratio, 3.02; 95% CI, 1.70 to 5.35; P<0.001), and gas trapping on expiratory CT (odds ratio, 2.05; 95% CI, 1.17 to 3.59; P=0.01). Free neutrophil elastase activity in BAL fluid at 3 months of age was associated with persistent bronchiectasis (present on two or more sequential scans), with the odds seven times as high at 12 months of age and four times as high at 3 years of age. CONCLUSIONS Neutrophil elastase activity in BAL fluid in early life was associated with early bronchiectasis in children with cystic fibrosis. (Funded by the National Health and Medical Research Council of Australia and Cystic Fibrosis Foundation Therapeutics.)