ABSTRACT
BACKGROUND: To improve monitoring of lung diseases, we analyzed cytokines in exhaled breath condensate (EBC). The main challenge in measurement of cytokines in EBC is the low protein content, which requires concentration steps that conflict with the need for excessive fluid required by most commonly used kits. METHODS: Here, a multiplex bead array for the detection of interleukins (IL) -1beta, -6, -8, -10, TNF-alpha, and IL-12p70 was modified and validated for analysis in EBC samples. Furthermore, 33 healthy volunteers and 11 patients with acute lung injury were investigated. RESULTS: In patients with inflammatory lung diseases, cytokine levels for all investigated cytokines were higher in comparison to healthy smokers or healthy volunteers. DISCUSSION: Multiplexed immunoassays in highly sensitive approaches allow for cytokine detection in EBC. We found significant differences between patients and controls for all investigated cytokines.
Subject(s)
Breath Tests/methods , Cytokines/analysis , Adult , Aged , Female , Flow Cytometry/methods , Humans , Interleukin-1/analysis , Interleukin-10/analysis , Interleukin-12/analysis , Interleukin-6/analysis , Interleukin-8/analysis , Male , Middle Aged , Pneumonia/immunology , Pneumonia/metabolism , Reproducibility of Results , Respiration, Artificial , Respiratory Distress Syndrome/immunology , Respiratory Distress Syndrome/metabolism , Smoking/immunology , Smoking/metabolism , Tumor Necrosis Factor-alpha/analysisABSTRACT
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.
