Changes in local and systemic inflammatory markers in cystic fibrosis patients chronically infected with Burkholderia cepacia complex

<b>Background:</b> Chronic infection with <i>Burkholderia cepacia</i> complex (Bcc) in patients with cystic fibrosis (CF) is associated with accelerated loss of lung function and increased mortality. In current literature there are a lot of the data on Bcc genetics, quorum sensing system, and virulence factors. However, very little is known about the changes of host inflammatory response during chronic Bcc persistence. <b>Objectives:</b> This study’s aim was to perform cross-sectional analyses of local and systemic biomarkers in CF pediatric patients who were chronically colonized with Bcc and those who were pathogen-free. <b>Methods:</b> 44 Bcc-infected and 56 Bcc-free patients were enrolled into the study. Blood and sputum samples were collected at the end of routine course of antibiotic therapy. Plasma ACTH and MMP-3 levels, as well as neutrophil elastase and cytokine concentrations in the sputum and plasma samples were assayed with commercially available kits. <b>Results:</b> There was a significant increase in sputum TNFα level in Bcc-infected patients compared to Bcc-free subjects. Bcc-infected patients demonstrated increased ACTH levels and elevated plasma elastase concentrations. In contrast, the levels of other systemic biomarkers including MMP-3 IL-17F, IL-18, IFNγ, TGFβ1were evidently lower than those in Bcc-free subjects. <b>Conclusion:</b> Decreased levels of systemic biomarkers in the patient with chronic Bcc infection may relate to more aggressive antibiotic therapy as well as Bcc-induced alterations of host inflammatory response. Further studies are needed to better understand the specific nature of the host-pathogen interactions during chronic Bcc colonization.