Presented at the Neonatal Society 2010 Autumn Meeting.
Hoo A-F1,2, Chudleigh J1,2, Ahmed D2, Lum S2, Wallis C1, Bush A3, Costeloe K4, Stocks J2, on behalf of the London CF Collaboration
1 Respiratory Medicine, Great Ormond Street Hospital for Children NHS Trust, London
2 Portex Respiratory Unit, UCL Institute of Child Health, London
3 Paediatric Respiratory Unit, Royal Brompton & Harefield Hospitals NHS Trust, London
4 Neonatal Unit, Homerton University Hospital NHS Foundation Trust, London
Background: Newborn screening (NBS) for cystic fibrosis (CF) has been available throughout the UK since 2007. NBS should potentially enable early intervention to preserve lung health and nutritional status in such infants. Prior to designing early therapeutic trials it is, however, essential to know both how feasible it is to recruit families into longitudinal studies with objective outcome measures of lung structure and function, and the extent of any baseline defects in lung function within the first few months of life in these children. We hypothesised that, when compared with prospective age-matched controls, NBS infants with CF have similar lung function at ~3 months of age. Research ethics committee approval was granted for this study.
Methods: All children presenting from the CF NBS programme from six centres comprising the London CF Collaboration were invited to participate in a study involving infant lung function (LF) under sedation at 3 and 12 months plus a combined CT, bronchoscopy and BAL under GA at ~12 months. Identical LF measurements were undertaken in prospective age-matched healthy term infants recruited from the Homerton University Hospital.
Results: During the past 20 months, 84 infants have screened positive for CF of whom 8 were ineligible (co-existent morbidities or moving away from area). Of the 76 eligible babies, 53 (70%) have consented to participate. LF assessments have been undertaken at 3 months in 51 CF infants (mean age at test: 10.9 [SD 2.3] weeks) and 36 healthy controls (12.4 [2.3] weeks). The lung clearance index (LCI: a measure of ventilation inhomogeneity) was significantly higher (95% CI: 0.1; 0.8, p<0.01) and forced expired volume in 0.5 second (FEV0.5) significantly lower (95% CI: –1.6; –0.7 z-scores (1), p<0.001) in infants with CF when compared to healthy controls. Of the 23 CF infants who have now reached one year of age, all have completed their follow-up lung function test and 22 have had their CT and BAL, with one awaiting an appointment.
Conclusion: Despite early diagnosis of CF, early implementation of prophylactic antibiotics and dietary support, lung function was significantly impaired by 3 months of age in those diagnosed with CF by NBS. Recruitment is continuing, but preliminary results suggests that it is feasible to recruit infants with CF diagnosed by NBS to a longitudinal study of lung function and structure within the first months of life.
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1. Lum et al, Pediatr Pulmonol 2010, 45:906–913