Inflammation in Achromobacter xylosoxidans infected cystic fibrosis patients

Abstract

Background: Achromobacter xylosoxidans infection may cause conspicuous chronic pulmonary inflammation in cystic fibrosis (CF) patients similar to Pseudomonas aeruginosa and the Burkholderia cepacia complex (Bcc). Evolution in lung function was compared in chronically infected patients. Cytokine concentrations in CF patients with and without chronic infection were compared to healthy controls.

Methods: Cytokines in serum and sputum were measured using multiplex bead based immunoassay.

Results: Sixty CF patients, 11 with A. xylosoxidans, 11 with Bcc, 21 with P. aeruginosa and 17 non-infected CF patients were compared to 11 healthy controls. A. xylosoxidans patients were younger, but had a FEV(1) decline similar to P. aeruginosa patients. Bcc patients had the steepest decline in FEV(1). Serum levels of G-CSF, IL-6 and TNF-alpha were significantly higher in CF patients compared to healthy controls. Chronically infected CF patients had significantly higher serum levels of IFN-gamma and IL-6 compared to non-infected CF patients. Bcc patients had significantly lower serum G-CSF and A. xylosoxidans patients had significantly higher sputum TNF-alpha compared to the other groups of chronically infected patients.

Conclusion: A. xylosoxidans can cause a level of inflammation similar to P. aeruginosa in chronically infected CF patients. A. xylosoxidans is a clinically important pathogen in CF and should be treated accordingly.