WS07.2 Bronchoalveolar lavage in children with cystic fibrosis and increasing Lung Clearance Index

Objectives Lung Clearance Index (LCI) is a promising tool to identify early lung disease in children with cystic fibrosis (CF). This retrospective study presents the findings in bronchoalveolar lavage (BAL) in children with CF and an increasing LCI-value and the possibility to reverse the LCI-value with a BAL-directed therapy. Methods 70 children with CF were monitored annually between October 2007 and April 2014 with Multiple Breath Washout (MBW) using SF6 as tracer gas. During this period 23 of 70 children (median 6.6 yrs, range 0.8–13.8 yrs) with an increasing LCI (not responding to treatment) or positive pseudomonas (PA) serum antibodies with negative PA sputum cultures underwent 31 BALs (minimum 1.9 yrs between BALs performed in the same child). Antibiotic treatment was ended 3 days prior to BAL. Results LCI and BAL-neutrophils correlated significantly (r = 0.572, p=0.001). In children with LCI≥7.8, 18 of 21 BAL-cultures were positive (≥1000 cfu/ml or a positive fungus culture) and only 2 of 10 BAL-cultures were positive when LCI Conclusion An increasing LCI in CF patients correlates with neutrophil inflammation and infection in BAL. An increasing LCI might be an indication for BAL to achieve a more effective treatment. Fungus may play an active role in causing neutrophil inflammation and an increasing LCI.