Abstract
Airway disease in cystic fibrosis (CF) is characterised by impaired mucociliary clearance, persistent bacterial infection and neutrophilic inflammation. Lipoxin A4 (LXA4) initiates the active resolution of inflammation and promotes airway surface hydration in CF models. 15-Lipoxygenase (LO) plays a central role in the “class switch” of eicosanoid mediator biosynthesis from leukotrienes to lipoxins, initiating the active resolution of inflammation. We hypothesised that defective eicosanoid mediator class switching contributes to the failure to resolve inflammation in CF lung disease.
Using bronchoalveolar lavage (BAL) samples from 46 children with CF and 19 paediatric controls we demonstrate that the ratio of LXA4 to leukotriene B4 (LTB4) is depressed in CF BAL (p<0.01), even in the absence of infection (p<0.001).
Furthermore, 15-LO2 transcripts were significantly less abundant in CF BAL samples (p<0.05). In control BAL, there were positive relationships between 15-LO2 transcript abundance and LXA4/LTB4 ratio (p=0.01, r=0.66) and with percentage macrophage composition of the BAL fluid (p<0.001, r=0.82), which were absent in CF.
Impoverished 15-LO2 expression and depression of the LXA4/LTB4 ratio are observed in paediatric CF BAL. These observations provide mechanistic insights into the failure to resolve inflammation in the CF lung.
Abstract
Reduced 15-LO2 expression in the lower airways of children with CF, associated with a depressed LXA4/LTB4 ratio http://ow.ly/tzZWa
Footnotes
This article has supplementary material available from erj.ersjournals.com
Support statement: This work was supported by grants from the National Children’s Research Centre, Ireland (E10/08), the Health Research Board of Ireland (1403 HRA_POR/2011/21) and Institut National de la Santé et de la Recherche Médicale, France.
Conflict of interest: Disclosures can be found alongside the online version of this article at erj.ersjournals.com
- Received June 21, 2013.
- Accepted February 3, 2014.
- ©ERS 2014