Exhaled breath condensate cytokine patterns in chronic obstructive pulmonary disease

Abstract

Differences in cytokine patterns in stable chronic obstructive pulmonary disease (COPD), exacerbated COPD, smokers without apparent COPD, and healthy volunteers should be of interest for pathophysiological and therapeutic reasons. Methods including lavage, biopsy and sputum have been employed to investigate cytokines in the lung. For asystematic comparison, exhaled breath condensate (EBC) appears to be well suited. We investigated healthy volunteers, smokers without apparent COPD, stable and exacerbated COPD patients (+/- inhalative steroids) and finally those whose exacerbation made mechanical ventilation inevitable, for a more complete picture of inflammatory cytokines in COPD. We chose EBC because it is non-invasive and can be used repeatedly in spontaneous breathing individuals and during mechanical ventilation. EBC cytokines (IL-1 beta, IL-6, IL-8, IL-10, IL-12 p 70, TNF-alpha) were assayed from a single sample using a multiplex array test kit. We observed a significant increase of all cytokines in acute exacerbation compared to stable COPD, smokers, and volunteers. Stable COPD and volunteers exhibited only small differences in cytokine pattern with respect to IL-1 beta and IL-12 (P<0.01). Smokers had increased levels of all investigated cytokines (P<0.01) compared to non-smokers and, with the exception of IL-1 beta, to stable COPD. Inhaled steroids resulted in reduced levels of IL-1 beta, IL-6, IL-8, IL-10, and IL-12 (all: P<0.01) in stable COPD (all: ex-smokers) with dose dependency for IL-8, IL-1 beta and IL-12. EBC analysis successfully characterized important differences in stable COPD compared to exacerbation or smoking and non-smoking healthy individuals.

Biomarker reproducibility in exhaled breath condensate collected with different condensers

“…The overall level of detection was 46-97%, which was much better compared with cytometric bead array in small samples in children (,50%), and in large 1,000-2,000-mL lyophilisated samples in adults (3-100%) [6,[23][24][25][26]. When compared with conventional (solid-phase) immunoassays, multiplexed immunoassays detect bioactive and inactive molecules, have a growing analytical range, are rapid (take hours instead of days to perform), have good precision (CV 10-15%), are not interfered with by drugs, and have simple protocols [7].…”

Association Between Single-Nucleotide Polymorphisms in Interleukin-12A and Risk of Chronic Obstructive Pulmonary Disease

“…It had been observed that increased expression of IL-12 was observed in lung epithelium cells and exhaled breath condensate of a COPD patient (Gessner et al, 2005). Thus, IL-12 may be an important factor in causing inflammatory diseases and be one of the candidate genes in the pathogenesis of COPD.…”

“…Interleukin (IL)-12 is a 70-kDa heterodimer composed of two disulfide-linked subunits of 35 kDa (IL-12A) and 40 kDa (IL-12B) (Ma et al, 1996;Maes et al, 1999;Commins et al, 2010). As an important immunoregulatory cytokine with an antagonistic effect of the Th1/Th2 cytokine balance, IL-12 provides a functional link between innate and acquired immune responses (Miteva and Stanilova, 2008), and it has been reported that IL-12 expression increased in tissues derived from a variety of inflammatory and autoimmune disorders, including COPD (Gessner et al, 2005). These suggested that IL-12 may be an important factor in causing inflammatory diseases and be one of the candidate genes in the pathogenesis of COPD.…”

Exhaled Breath Condensate: An Overview

“…A 1 ml EBC sample (collected in 7 minutes for example), can be lyophilized and resuspended into 50 uL -a 20-fold concentration. The advent of multiplex bead arrays has allowed for the tiny reconstituted volumes to be used for multiple immunoassays concurrently, opening up an exciting potential, with proof of concept already in place (20), to gain a broad window on the balance among cytokines (or other mediators) in the airway lining fluid during any respiratory state. The issue of variable dilution remains (unless dilution factors are analysed), but the ratios among the cytokines are likely valid as long as sufficient assay controls have been performed.…”