S82 Airway Inflammation is Present by 4 Months in CF Infants Diagnosed on Newborn Screening
Introduction Cystic fibrosis (CF) newborn screening (NBS) allows early introduction of treatment, often before any symptoms arise with the aim of reducing airway infection and inflammation. UK nationwide screening began in 2007.
Aims It is usual clinical practise at our centre to perform fibreoptic bronchoscopy (FOB) at the age of 3 months for all children with CF. The aim of this study was to establish the presence of infection and degree of inflammation in airways in the NBS cohort. Bronchoalveolar lavage fluid (BALF) was cultured and examined for cellular inflammation.
Results Infants diagnosed by NBS undergoing routine FOB who had either BALF absolute cell count or differential cell count assessed were included in the study. 44 infants (48% female), median age (range) 15 (7–28) weeks met these criteria. The majority of these infants were symptom free however 13 (29%) had bacterial isolates from their BALF. Comparable data are also available for 71 children with established CF (median age 9.5 years; range 1.9–16.7 years) of whom 46 (65%) were BALF culture positive and for 6 healthy controls (median age 12.3 years, range 10.5–15.4 years).
Cellular inflammation was present in the airways in infants diagnosed by NBS, both in those who were culture positive and negative in their BALF. Absolute BALF cell count and neutrophil differential were significantly higher in both NBS and established CF patients compared with healthy controls (p<0.02). Median absolute cell counts and neutrophil differentials can be seen in table 1. For both NBS and established CF, in those who had bacteria isolated from their BALF, an increase in neutrophil differential was seen compared with those culture negative at the time of FOB although this did not reach significance in the NBS group. (NBS CF p= 0.05, established CF p<0.01).
Conclusion Our results demonstrate that inflammation is already present by 4 months of age in asymptomatic infants diagnosed through NBS, although at a lower level than seen in established CF. The results underscore the importance of early surveillance and lend support to the evolving focus on this age group for interventional trials.