Article Text
Abstract
Background Long-term benefits of newborn screening (NBS) for cystic fibrosis (CF) have been established with respect to nutritional status, but effects on pulmonary health remain unclear.
Hypothesis With early diagnosis and commencement of standardised treatment, lung function at ∼3 months of age is normal in NBS infants with CF.
Methods Lung clearance index (LCI) and functional residual capacity (FRC) using multiple breath washout (MBW), plethysmographic (pleth) FRC and forced expirations from raised lung volumes were measured in 71 infants with CF (participants in the London CF Collaboration) and 54 contemporaneous healthy controls age ∼3 months.
Results Compared with controls, and after adjustment for body size and age, LCI, FRCMBW and FRCpleth were significantly higher in infants with CF (mean difference (95% CI): 0.5 (0.1 to 0.9), p=0.02; 0.4 (0.1 to 0.7), p=0.02 and 0.9 (0.4 to 1.3), p<0.001, z-scores, respectively), while forced expiratory volume (FEV0.5) and flows (FEF25–75) were significantly lower (−0.9 (−1.3 to −0.6), p<0.001 and −0.7 (−1.1 to −0.2), p=0.004, z-scores, respectively). 21% (15/70) of infants with CF had an elevated LCI (>1.96 z-scores) and 25% (17/68) an abnormally low FEV0.5 (below −1.96 z-scores). While only eight infants with CF had abnormalities of LCI and FEV0.5, using both techniques identified abnormalities in 35% (24/68). Hyperinflation (FRCpleth >1.96 z-scores) was identified in 18% (10/56) of infants with CF and was significantly correlated with diminished FEF25–75 (r=−0.43, p<0.001) but not with LCI or FEV0.5.
Conclusion Despite early diagnosis of CF by NBS and protocol-driven treatment in specialist centres, abnormal lung function, with increased ventilation inhomogeneity and hyperinflation and diminished airway function, is evident in many infants with CF diagnosed through NBS by 3 months of age.
- Infants
- CF
- lung function tests
- newborn infant screening
- cystic fibrosis
- lung physiology
- respiratory measurement
- asthma guidelines
- exhaled airway markers
- paediatric asthma
- paediatric lung disease
- paediatric physician
- paediatric lung disaese
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Footnotes
Funding This study is supported by grants from the Cystic Fibrosis Trust, UK; Special Trustees: Great Ormond Street Hospital for Children, London, UK; Smiths Medical Ltd, UK; Comprehensive Local Research Network, UK. It was also supported by the NIHR Respiratory Disease Biomedical Research Unit at the Royal Brompton and Harefield NHS Foundation Trust and Imperial College London.
Competing interests None.
Patient consent Obtained.
Ethics approval Ethics approval was granted by the North Thames Multi-centre Research Ethics Committee (REC) (#09/HO71/314) and local REC of the participating specialist centres.
Provenance and peer review Not commissioned; externally peer reviewed.
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