Early Pseudomonas aeruginosa predicts poorer pulmonary function in preschool children with cystic fibrosis.

BACKGROUND

We previously reported relatively normal pulmonary function (2 years of age) and computed tomography (CT, 1 year of age) in cystic fibrosis (CF) newborn screened (NBS) infants. We now report follow up of these children to preschool age.

METHODS

67 NBS children with CF and 41 healthy controls underwent pulmonary function tests in infancy (∼3 months, 1 year and 2 years) and at preschool (3-6 years). Broncho-alveolar lavage (BAL) and CT were undertaken in those with CF at 1 year. Primary outcomes at preschool were lung clearance index (LCI) and forced expired volume (FEV). Risk factors for lung function impairment were identified by regression modelling, emphasising factors that could be identified or measured in the first 2 years of life.

RESULTS

At preschool age children with CF had poorer lung function than controls, mean(95% CI) difference in LCI z-score: 1.47(0.96;1.97) and FEV z-score -0.54(-0.98; -0.10). Isolation of Pseudomonas aeruginosa before 6 months was a highly significant predictor of raised (abnormal) preschool LCI, associated with a mean (95%CI) increase of 1.69(0.43, 2.95) z-scores, compared to those with no Pseudomonas aeruginosa during the first 2 years of life. Including 2 year LCI and 1 year CT data in the predictive model increased the r from 13% to 61%.

CONCLUSIONS

Lung function deteriorates after 2 years in NBS children with CF. Isolation of Pseudomonas aeruginosa before 6 months and minor abnormalities of infant lung function tests and CT in infancy are associated with higher preschool LCI.