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 _0.75 ). 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 _0.75 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 ² 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.
Competing Interests: Declaration of Competing Interest Dr Aurora received grant funding from Action Medical Research, The Henry Smith Charity and the Cystic Fibrosis Trust for this work. Other authors have no conflicts of interests to declare.
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