Clinical correlation of epithelial barrier dysfunction related to neutrophilic inflammation in cystic fibrosis

<b>Introduction:</b> Cystic Fibrosis (CF) is characterized with chronic inflammation with neutrophil and related cytokines in aırway secretions. We aimed to measure the levels of neutrophil related inflamatory markers such as nitric oxide(NO), IL-8, IL-17, LTB4 and neutrophil elastase(NE) as well as e-cadherin in exhaled breath condensate(EBC) and to determine their correlation with clinical findings. <b>Methods:</b> We consecutively enrolled CF patients in our clinics aged above five years who could cooperate for exhaled breath condensate to this case-control study(n=30). The age and sex matched control group(n=26) was enrolled consecutively among the patients. Spirometry was performed during the stable period and EBC samples were obtained for measurement of the markers. <b>Results:</b> Mean age of subjects enrolled was 12.1(4.2)years and %40 were positive for Pseudomonas Aeroginosa(PA) in sputum. Subject who had PA in sputum cultures had significantly lower FEV1, FVC, FEF25/75 values compared to the ones without PA(P=0.002,P=0.002andp=0.005). EBC NE levels were significantly higher in the CF patients compared to non-CF controls(p=0.004).NO, IL-8, IL-17, e-cadherin, NE or LTB4 levels in EBC of CF patients were not related to PA infection, FEV1 levels or hospital admission in the last year. <b>Conclusion:</b> NE levels in EBC, as a marker of neutrophilic inflammation suggested to play an important role in pathogenesis, are higher in CF patients compared to non-CF controls. This is independent of acute infection and is evidence to persistence of neutropilic lung injury. EBC NO, IL-8, IL-17, e-cadherin, NE and LTB4 levels as inflammatory markers, are not correlated with disease progression or clinical findings.