Lung function is abnormal in 3-month-old infants with cystic fibrosis diagnosed by newborn screening
- Ah-Fong Hoo1,
- Lena P Thia2,
- The Thanh Diem Nguyen2,
- Andrew Bush3,
- Jane Chudleigh1,
- Sooky Lum2,
- Deeba Ahmed2,
- Ian Balfour Lynn3,
- Siobhan B Carr4,
- Richard J Chavasse5,
- Kate L Costeloe6,
- John Price7,
- Anu Shankar8,
- Colin Wallis1,
- Hilary A Wyatt7,
- Angela Wade9,
- Janet Stocks2,
- on behalf of the London Cystic Fibrosis Collaboration (LCFC)
- 1Respiratory Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- 2Portex Respiratory Unit, UCL Institute of Child Health, London, UK
- 3Department of Paediatric Respiratory Medicine, Imperial College & Royal Brompton & Harefield Hospital NHS Foundation Trust, London, UK
- 4Department of Paediatric Respiratory Medicine, Barts & The London Children's Hospital, London, UK
- 5Queen Mary's Hospital for Children, Epsom & St Helier University Hospitals NHS Trust, Surrey, UK
- 6Neonatal Unit, Homerton University Hospital NHS Foundation Trust, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
- 7Department of Paediatric Respiratory Medicine, Kings College Hospital, London, UK
- 8Department of Child Health, Lewisham Healthcare NHS Trust, London, UK
- 9Centre for Paediatric Epidemiology & Biostatistics, UCL Institute of Child Health, London, UK
- Correspondence to Dr Ah-Fong Hoo, Respiratory Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK;
Contributors Conception and design of the study: JS, AB. Supervision of the study: JS. Research governance issues including ethics committee approval: JS, JC. Setting up of recruitment process: AFH, JC. Technical training, supervision and audit of data collection/analyses: AFH. Recruitment of infants with CF: AB, IBL, SBC, HAW, JP, RJC, AS. Recruitment of healthy control infants: KLC, AFH, DA, LPT, TDN, JC. Data collection/analysis and interpretation of results: JS, AFH, LPT, TDN, JC, SL. Statistical analyses: AFH, JS, AW. Drafting the manuscript: AFH, JS, LPT, IBL, AB, CW. Approval for intellectual content: all authors.
- Received 10 February 2012
- Accepted 25 May 2012
- Published Online First 29 June 2012
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.
- 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
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.