Antimicrobial peptide levels are linked to airway inflammation, bacterial colonisation and exacerbations in chronic obstructive pulmonary disease

[摘要] Antimicrobial peptides (AMPs) are effectors of host defence against infection; inflammation and wound repair. We aimed to study AMP levels in stable chronic obstructive pulmonary disease (COPD) and during acute exacerbations of COPD (AECOPD); and to examine their relation to clinical parameters and inflammatory markers.The 3-year Bergen COPD Cohort Study included 433 COPD patients and 325 controls. Induced sputum was obtained and analysed for levels of the AMPs human cathelicidin (hCAP18/LL-37) and secretory leukocyte protease inhibitor (SLPI); and for the inflammatory markers interleukin (IL)-8; IL-6 and tumour necrosis factor-xcexb1 (TNF-xcexb1) using immunoassays. Systemic hCAP18/LL-37 and vitamin D levels were also studied. Treating AMPs as response variables; non-parametric tests were applied for univariate comparison; and linear regression to obtain adjusted estimates. The risk of AECOPD was assessed by Cox proportional-hazard regression.Sputum AMP levels were higher in patients with stable COPD (n=215) compared to controls (n=45); and further changed during AECOPD (n=56); with increased hCAP18/LL-37 and decreased SLPI levels. Plasma hCAP18/LL-37 levels showed a similar pattern. In stable COPD; high sputum hCAP18/LL-37 levels were associated with increased risk of AECOPD; non-typeable Haemophilus influenzae colonisation; higher age; ex-smoking and higher levels of inflammatory markers.Altered levels of selected AMPs are linked to airway inflammation; infection and AECOPD; suggesting a role for these peptides in airway defence mechanisms in COPD.

[学科分类] 呼吸医学