Lung function deteriorates after 2 years in children with cystic fibrosis (CF), according to a new study published in the Journal of Cystic Fibrosis.

The study also showed that the isolation of Pseudomonas aeruginosa before 6 months of age and minor abnormalities in infant lung function tests are associated with a higher preschool Lung Clearance Index (LCI) in these patients.

A team of researchers from the UK analyzed 67 children with CF identified through newborn screening and compared them to 41 healthy controls. They previously reported that the computed tomography (CT) images and the lung function of the children were relatively normal at 1 year and 2 years, respectively.

The researchers then followed the children to preschool age or aged 3 to 6 years. In the present study, they report that children with CF had poorer lung function compared to children the same age without the disease. The isolation of P. aeruginosa before 6 months of age was a highly significant predictor of abnormal preschool LCI.

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These data show that the LCI increases between 2 years and preschool age in children with CF and that the early growth of P. aeruginosa is the strongest clinical predictor of this deterioration, the researchers concluded.

“Minor abnormalities of LCI and CT during infancy are also associated with future lung function decline, and may be helpful in identifying children who will benefit from intensified therapy,” they wrote. They said that relatively minor changes in lung function and abnormalities in CT scans should not be ignored and treatment should start before 2 years of age.

The LCI is a sensitive measure of ventilation inhomogeneity that reflects abnormalities in the smaller airways, which is accepted as being the site of early lung injury in CF. P. aeruginosa is the major cause of lung infection in patients with CF.


Aurora P, Duncan JA, Lum S, et al. Early Pseudomonas aeruginosa predicts poorer pulmonary function in preschool children with cystic fibrosis. J Cyst Fibros. Published online May 1, 2022. doi:10.1016/j.jcf.2022.04.013