[Longitudinal evaluation of pulmonary function tests in children with newborn screening for cystic fibrosis. Relationships with pulmonary infection. Study of 40 children undergoing 744 pulmonary function tests].

OBJECTIVES:To report longitudinal assessment of pulmonary function in children with neonatal screening for cystic fibrosis and its relationships with Pseudomonas aeruginosa (PA) chronic infection, nutritional status, sex, age and genotype. POPULATION AND METHODS:Children benefited systematically of 3 visits a year with pulmonary function tests (PFT) and bacteriological examination. Forty children and 744 PFTs were analysed, with 38 children during at least 4 years. RESULTS:We reported a decrease of pulmonary function tests with chronic PA infection and the genotype DeltaF508/DeltaF508. The decline was gradual and not different between not infected and recently infected children. The PFTs of children infected for a long times were very deteriorate, probably due to the fact that they were infected with multiresistant strains of PA. CONCLUSION:We think that it is important to survey pulmonary function before 5 years old in these early infected children. We should determinate if the important decrease of PFT in these early infected children is due to infection by PA mucoid.